HYBRIDIZING BASICS

 FOR AIS GARDEN JUDGES AND YOUTHS OF ALL AGES

By Donald (Don) Matthews Spoon, Ph. D.  Fall, 2011. Winterberry Gardens. Cross Junction, VA.

Iris Crossing. Parts of this article were prepared for training AIS garden judges on the basics of hybridizing bearded irises - the pogons - that can have exotic fragrances and a complete rainbow of colors to attract pollinators.  Bearded irises are placed in classifications based on stalk heights and time of blooming: MDB-miniature dwarf bearded (under 8”) earliest, SDB-standard dwarf  (8” to16”) early, IB-intermediate (16” to 27.5”) middle, BB-border (16” to 27.5”) late, MTB-miniature tall  (16” to 27.5”) late, and TB-tall (over 27.5”) late.  The in between height classifications, SDBs IBs, BBs, and MTBs are called medians. In this article, a cultivar without class designation is a TB.  As president of the Chesapeake & Potomac Iris Society of Region 4, I am directing this summary article to our seven new iris hybridizers, youths 13, 14, 16 and 18 years old, plus three over 19.  We have two spring hybridizing clinics where youths may each make five crosses. We provide a hybridizing kit for each youth.  I follow their successful seedpods and prepare their seeds; they then plant in their own gardens. Watching with their parents, these youths with their friends gleefully crossing irises in our garden is pure joy.  They are the future, great hybridizers of the American Iris Society.  Hybridizing irises, like life, may be like a box of chocolates.  We do not know what we will get.  But learning to be a chef who knows the recipes of the confections may remove some of the mystery.  Yet, hybridizing bearded irises will always be more mystery than science.  Your hybridizing tweezers, like a magic wand, can create wonderful beauty.   

Easy Genetics. This article has been expanded to be clearer and more complete than the 7-page handout in large font, used in the garden judges training.  One participant, after looking over the handout, asked me if it was written in English.  Many believe that Genetics is Greek to them, it goes over their heads and is beyond their comprehension.  Actually, the basics are like the simplest forms of math, like 1+1=2, 2+2=4, and 4 divided by 2 is 2.  To master Genetics and all its advanced textbooks, for its many applications, would take many lifetimes.  There are many thousands of published papers just on the Genetics of Arabidopsis thaliana, the rockcress in the mustard family.  To be a successful iris hybridizer, just take the time to learn the basic Genetics presented in this relatively short article.  Remember the words of Thomas Jefferson, “Luck favors the prepared mind.”  Increasing your basic knowledge of Genetics can increase your chances for hybridizing success. 

Easy Lexicon.  Scientific terminology comes mostly from Greek and Latin. The genus name Iris is from the Greek name for their rainbow goddess.  The scientific word for bearded irises is “pogon” from the Greek word for beard.  Whereas “bearded” can be replaced by a different native word in the 7,000+ spoken languages of our 7,000,000,000 humans, the scientific term POGON is always spelled, pronounced, and used to mean the same thing in any language.  Pogon separates the bearded irises from the beardless that are called “apogon” or without beards.  This article uses about 50 scientific words, while avoiding as many as possible.  Most educated people know over 50,000 words in their own native tongue.  It seems a small task to add to your repertoire of words 50 scientific terms that can be written and pronounced, and have the same meaning in every languages on earth.  I was often told, “Use of a dictionary (lexicon) will not cause irreparable brain damage.”  Learning to use correctly 50 scientific terms, such as locus and allele, could allow you to grasp the basic genetic concepts needed to successfully hybridize irises.

Glorious Rebloom. We held our judges training in the third week of October, during our Region 4 fall meeting, to showcase many reliable rebloomers in full bloom.  Many of these began reblooming in early September; and some like MDB ‘Trimmed Velvet’, SDBs ‘Purple Joy’ and ‘Ray Jones’, and TB ‘Corn Dance’ are so cold hardy, they may continue reblooming until Thanksgiving in our zone 6b.  As we continue to intercross the best fall rebloomers, they will produce seedlings that rebloom earlier, even in July and August, with more flower stalks, and with better cold hardiness to withstand fall and spring frosts and freezes.  We envision in the near future when these new rebloomers will compete with chrysanthemums for their vibrant fall colors, growing and reblooming in large, deep pots, then planted in a garden to enjoy in spring and fall. Ginny had a dream about driving around Winchester and being awed by the reblooming irises that blanketed the neighborhoods.  My dream is that many youths and youthful minded iris growers will decide to become iris hybridizers so Ginny’s dream can come true.   

“Live Long and Prosper”.  For many hybridizers, their incentive for growing, blooming, and hybridizing irises, is to sell their introductions to support their hobby, themselves, or even their family.  A hybridizer who masters the procedures and concepts summarized in this article could be seeing their first seedlings bloom in two years and begin selling their first introductions in four to five years.  Eventually, they could clear over costs up to $10,000 or more per acre of planted irises if they use their land as well as their advertising and purchasing funds wisely.  You could support a family of four on a five-acre iris farm with good topsoil. 

Their Plot.  May I suggest to parents that they offer to their youths a sunny garden plot solely for them to tend of up to 40 by 40 feet.  There they can grow their collection of iris cultivars for breeding stock and learn how to hybridize bearded irises as an avocation or possibly a vocation.  They will get lots of sun and exercise and eventually earn spending money, and maybe even enough to buy their first vehicle.  Each iris cultivar is a living plant with tens of thousands of genes and the ability to produce gloriously beautiful flowers.  Bearded irises are the regal queens of any garden scene and are cherished by gardeners as a choice perennial. They are among the easiest perennials to grow, especially the reblooming cultivars.

Top Start from Oz.  Repeating the crosses in both directions of top award winners is a good way to start.  The brilliant cross that produced for Australian Barry Blyth the zone 9 rebloomer and Wister Medal winning ‘Decadence’, was ‘Temple of Time’ X ‘Louisa’s Song’.  Barry has championed making crosses in both directions, pod X pollen and pollen X pod parents, as the results can be quite different.  The potential diversity of seedlings in such a cross is over a quadrillion (at least 24 X 24, 24 times or 24 factorial), and repeating the crosses of other hybridizers should be encouraged.  You may also want to add a few self crosses of your tallest and most vigorous cultivars or seedlings.  Crossing your best cultivars or seedlings back on either parent or its sibling can produce some unique offspring, some superior to either parent.  Always save your second best sibling from a cross that produced an exceptional seedling for sibling crosses.  Some successful hybridizers believe in limiting their inbreeding at first cousin crosses, yet the results obtained with closer inbreeding in tetraploids such as self, sibling, and parent crosses speak for themselves.  Such aversion to closer inbreeding might delay successful progress.  For example, I crossed my Wister Medal winning ‘Uncle Charlie’ on a sibling of ‘Lady of Leoness’ from the reverse cross of ‘Honky Tonk Blues’ X ‘Silverado’ that produced ‘Uncle Charlie’.  From this reverse sibling cross, I obtained my ‘Orchid Dove’ that got the most votes for TBs at the Wisconsin AIS National Convention. ‘Orchid Dove’ has several recessive traits not found in either parent or grandparent.  I converted their two doses to four doses for hidden recessive traits and expressed lace, orchid pink coloration as seen in the Dykes Medal winner ‘Mary Francis’, dove blue pigment, etc. ‘Orchid Dove’ is a vigorous grower with good increase and is an excellent parent.  The master judge Perry Dyer said, “It is gorgeous!”  Once an introduction leaves your garden, any praise or awards it receives must be earned on its own merits.  AIS garden judges know that their greatest responsibility is to vote  for the cultivar and not its hybridizer, based on personal observations of garden clumps and not photographs or catalogs.  Personal observations of show stalks have limited usefulness as they lack performance in the garden.     

Selfed by Crawling Insects.  Random outcrossing seldom produces superior seedlings. In modern bearded irises there are few pods, except in a few dwarfs and MTBs, that are randomly crossed by flying insects like bees and bumblebees, as the stigmatic lips are too highly positioned.  This is why you do not have to remove the falls after making a cross as required with beardless irises. Those who have had success planting seeds from “bee crosses” such as Dick Sparling, most likely planted seeds from a selfing by crawling insects. Failure to remove all three stamens greatly increases the chances for such selfing. Most hybridizers throw away all pods they did not cross.  We plant the seeds from such pods on the best cultivars assuming they are self crosses, and have obtained some of our most unique seedlings with good vigor from these mystery pods.  Test self crosses gave similar seedlings.  We make about 50 self crosses each year that set few pods, yet they can express novel recessive traits and even uncover a new, hidden mutation.  Selfing the same flower rarely works.  To make a successful self, use mature pollen from an older flower on a newly opened flower.

Look-a-likes.  In outcrossing, using look-a-likes is usually more successful than unlikes, in which few seedlings will surpass either parent. Likes X likes is especially important when the traits you are pursuing are recessives like tangerine beards or the plicata pattern.  Once you learn how to hybridize, you will often cross unlikes, as a pink on a plicata.  For example, cultivars carrying two recessive, unexpressed doses of plicata like the vigorous, modern-flowered bicolor ‘Little John’, with pink standards and lavender falls are useful when crossed on plicatas or variegated flower pod parents.  ‘Little John’ came from a cross of a pink times a reliable plicata rebloomer that gave it two doses of recessive plicata and zone 9 rebloom.  Richard Ernst got his Wister Medal winning ‘Ring Around Rosie’ with purple sanded fall pattern with yellow rim with a triple sibling cross {(sib x sib) Sibling X (sib x sib)} of the pink ‘Edna’s Wish’ on the complex plicata ‘Wild Jasmine’.  Ernst produced a series of beautiful cultivars such as ‘Carnival Ride’ and ‘Looky Loo’ using sibling crosses.  George Shoop was probably the greatest master of inbreeding, often using sibling crosses.   Study the crosses with dwarfs by the late Bennett Jones in his small garden plot and learn his successful methods. There are many knowledgeable hybridizers who will gladly answer your questions by e-mail, mail, or by phone when they are available, and even schedule you a visit to their garden at a time of day when they are not busy hybridizing.

Select and Collect.  Another successful strategy is to collect and use cultivars that are known to be great parents like ‘I Do’, ‘Vanity’, ‘Titan’s Glory’, ‘Suspicion’, ‘Queen’s Circle’, ‘Romantic Evening’, ‘Fancy Woman’, and ‘My Ginny’.  Select for your collection known rebloom carriers like ‘Spinning Wheel’, ‘Yaquina Blue’ and ‘Starring’ that are good parents.  Obtain some of the best reliable rebloomers including those that bloom early in the fall as well as late summer.  Select rebloomers with cold hardy stalks that can withstand early fall and late spring frosts.  Other growers may allow you to gather pollen in their gardens or give you flower stalks they entered in shows.  Buying or trading for the less expensive, best older cultivars will stretch your funds and still yield good seedlings. There are many ways to gain knowledge to invest wisely in the newest and best cultivars to use for your specific goals. You can attend local iris shows or regional and national conventions.  You can read iris books, catalogs, and articles from the AIS Irises, section publications (TheRebloomingIrisRecorder), and TallTalk. You can search through web sites for commercial sources of irises and the AIS website (irises.org) where you can click on the Iris Encyclopedia (wiki.irises.org).  Iris cultivars over 30 years old are called historics, those newly introduced in the last ten years we call moderns, and those in between we call classics.  As the years progress, there are now many inexpensive classics that are nearly as good as the best moderns.  There are many colors and color patterns found only in the historics and classics that lack reliable rebloom and need improvements in form and vigor.  Prices drop from $20-75 (SDBs to TBs) the year of introduction, to $5-15 in five years and $3-5 in ten years. Unlike daylilies, hostas, peonies, etc. costing hundreds of dollars when introduced, only two introduced TB irises, space age ‘Unicorn’ in 1954 and super rebloomer ‘Immortality’ topped out at $100.  Now, a few TBs are introduced at $75, but most are $35 - $60.  Buying cultivars you have seen performing well in private and commercial gardens in your climate zone is a good practice. Assembling about 100 choice cultivars selected specifically as breeding stock is a good start.  If you begin with a single goal where there is little competition, even 5 could be a good start.  You have to invest in maintenance of each cultivar you add to your collection, so choose each one carefully.  You should feel free to remove from your collection any that under perform in your zone. In your second year, you should have increase from your collection to sell.  In a few years, you will have your own vigorous reselects for planned crosses to reach specific goals and begin your program of successful line breeding. 

Lasting Signs.  For our permanent metal garden signs we use stainless steel signs from Kincaid Gardens, 11000 County Road 366, Savannah, MO 64485-2312 <www.kincaidgardens.com>. For a few labels, we use Brother P-touch ® laminated label maker with one inch wide tape for two lines for cultivar name, hybridizer, year of introduction, classification and rebloom.  For larger projects, we use Avery ® 5520 weatherproof address labels from the Staples catalog center.  With these Avery ® labels, you should use a laser printer that won’t wash off.  Ginny uses a database, either from Works or Excel. Then she selects the fields to print, and can make hundred of labels this way.  These laser printed labels last 10 years or more without fading while the stainless steel signs will last many lifetimes.  An inexpensive way to make signs to label reselects and seedbed crosses is to use 9” sections of 1” wide vinyl venetian blinds.  Insert, by the cut pointed end, halfway into the soil. Repeat the information in the top and bottom half so if the top is broken off by an animal, you still have it labeled.  A pencil will write on this vinyl surface and the graphite will stay indefinitely, unlike “permanent” markers whose ink is removed by sunlight in a year or less.  Rough handling of the vinyl surface, especially when wet, can rub off some of the graphite.  Punch a hole in the bottom pointed end of the vinyl strip.  Then wrap on itself a thick rubber band through the hole that will prevent the sign from heaving in winter.  Keep current your maps of all your garden plantings.  Animals can remove signs.   Making maps should be the first thing you do when you plant.

Introduce Yourself.  You will learn the value of selecting cultivars for introduction that are vigorous growers and have at least three increases per year. You should build up your stock before the year of introduction to at least 50.  This will take three or four years; however, in warm climate zones or with exceptional increasers you may reach this number in two years.  Eventually, you may master early seed germination methods, growth inside under lights or in a greenhouse, and even embryo culture to accelerate this process.  Plan to save at least 15 good plants to replant and increase back to 50 by the next year.   You will need 3 of your largest plants of your best cultivars to send to the AIS national convention where garden judges and experience growers will appraise its flowers, stalks, and two-year growth in 3 different guest gardens.  If you sell 25 plants at $40 each, you will gross $1,000.  In its first year of introduction, ‘Daughter of Stars’ that can have 8 increases per year, sold over 100 plants grossing over $4,000 from a 4’ by 8’ raised production bed.  A cultivar sold at $50 in 64 square feet would gross $10,000.  If you have a superior cultivar, hold back introduction until you have over 100 plants, or over 200 if it is also a reliable rebloomer.  You may have enough to send to some regional competitions. 

Sets in Classes.  Most modern bearded irises are TETRAPLOID (4N) with larger flowers, taller stalks, and sometimes more vigor, and their gametes are DIPLOID (2N).  Diploid historic cultivars and species have 2 sets (2N) of chromosomes; their gametes have 1 set (1N) called haploid.  Diploids very rarely make fertile offspring when crossed on tetraploids unless the diploid forms a gamete that does not reduce by half in meiosis and is diploid.  Diploids can be converted into tetraploids with colchicine and other chemicals, but this conversion requires careful procedures.  Most modern TBs, BBs, and MTBs have 48 CHROMOSOMES in 4 look-a-like sets of 12 different chromosomes and can be intercrossed producing fertile offspring.  Because of the bell shaped curve of possible stalk heights - a polygenic (many gene) trait - two parents with shorter stalks can produce occasional offspring with much taller or shorter stalks.  MDBs and SDBs can have variable chromosome numbers, yet many cross on one another producing fertile offspring.  SDBs X TBs crosses give IBs that are usually infertile hybrids with variable chromosome sets, but can have hybrid vigor; and some have limited fertility.  IBs bloom between the other classes and can be great, low maintenance garden plants.  IBs offer good possibilities for new hybridizers by crossing the best SDBs and TBs with similar traits.  For his first cross, Lowell Baumunk crossed rebloomers, TB ‘Best Bet’ X SDB ‘What Again’, and obtained a deep violet IB rebloomer, the incomparable ‘Midsummer Night’s Dream’ with some fertility that won the top AIS yearly IB award.  

Only You Decide.  It is good to chose unique cultivars for introduction; however, look-a-likes adding reliable rebloom and/or extraordinary garden performance can be big successes.  Seedlings with slight improvements over introduced look-a-likes should not be introduced.  In a garden training, Perry Dyer said, “If you have doubts about introducing your seedling, then don’t introduce it.” Yet, it is entirely your decision to make.  You can err on the side of being overly cautious. Other growers may really like your cultivar.  There is no such thing as a perfect cultivar with all pros and no cons, but some like IB ‘Starwoman’, ‘Stairway to Heaven’, and ‘Dusky Challenger’ come close.  If you added to them reliable rebloom, even down to zone 6, you would have a winning introduction.  ‘Dusky Challenger’ is pod fertile, yet rarely produces pollen; but it is a rebloom carrier, so even one well-planned cross might suffice.  Monty Byers was ready to compost ‘Thornbird’, but others liked it.  Monty decided to introduce it and it won a Dykes Medal.  It is one of the most widely grown and admired cultivars.

Karyotyping. To count the number of chromosomes, treat a growing root tip with cells in various stages of mitosis with colchicine.  This antimitotic agent dismantles the spindle fibers attached to each side of the kinetochore of the chromosome.  The spindle fibers would have pulled apart the two identical, joined chromatids of the chromosome into two newly formed cells.  We call these condensed structures arranged on the metaphase plate “chromosomes”, yet these x-shaped structures are two identically replicated chromatids. You can make a squash of these cells, then stain and photograph all the chromosomes.  Like ones can be arranged to form a karyotype that in humans has 22 similar X-shaped pairs, plus a pair of sex chromosomes, the X and small Y.  In a tetraploid iris, there would be 48 chromosomes, each composed of two chromatids, and you could arrange 12 sets of similarly shaped ones in rows of four.  In plants, there are no distinguishable sex chromosomes.  Some chromosomes have constrictions near their ends forming thinner, rounded satellites that can be deleted with their genes for various traits like those producing sexual structures.  Flat-tops may be deletions that lost the genes to form upturned standards, stamens, etc.   

Divide and Multiply.  In MITOSIS, cell division, the chromosome number and DNA sequence of nucleotides remains constant.  However, a SOMATIC MUTATION can occur either with a deletion or addition of chromosome material or by a POINT MUTATION with a nucleotide change that alters the three base DNA code that changes the amino acid sequence in a protein and its function.  Somatic mutations are called sports.  In MEIOSIS, reduction and division, the chromosome number is halved (2N to 1N in diploids or 4N to 2N in tetraploids) to produce gametes.  Similarly shaped, (HOMOLOGOUS) chromosomes (homologs) with two identical CHROMATIDS produced in cell division I of meiosis join together (SYNAPSE) as chromatid tetrads in diploids and octeds (8) in tetraploids.  This joining together allows many CROSSOVERS to occur, yet more often in the tetraploids than diploids. This synapsing of chromosomes to find their partners in each set is one of the great miracles of life considering that some sexually reproducing organisms have over a thousand chromosomes. In meiosis division II, there is no replication of the DNA, chromosomes, or their kinetochores that hold the two replicated chormatids of the chromosome together.  Meiosis division II, without replication, yields reduction of the chromosome number.  In meiosis division II in diploids, there is a tetrad of four chromatids of a set of two similar synapsed chromosomes.   In tetraploids there is an octed with eight chromatids to be separated into two cells. Which chromosomes of the pairs in diploids or the quartets in tetraploids that goes to either gamete is random, having either maternal or paternal origin.  This is the independent, random assortment of the maternal and paternal chromosomes and of all their particulate genes that can determine inherited traits. Crossovers are more likely to occur in genes further from the kinetochore.  Crossovers allow unlikely exchanges of paternal and maternal genes that change the expected gene frequencies in the gametes. 

Pogon Lowdown.  Bearded irises are higher plants producing long-lived seeds with two seed coats.  They are monocotyledons (meaning one seed leaf) with parallel vascular bundles in the leaves. Vascular bundles interconnect the whole iris plant appearing as veins in the flower parts.  They are wrapped in strength-giving sclerenchyma and have phloem carrying nutrients down to the roots and xylem vessels carrying water, minerals, and nutrients up from the rhizome and roots.  Large vascular bundles give stalks peripheral support; however, turgor pressure adds to the strength of the stalk that is lost if it is frozen or the plant is dug up while sending up stalks.  Some rebloomers with winter hardy foliage have winter tender stalks that cannot withstand an early fall freezing frost and lose turgor pressure and collapse.  

Pollen Grains are Plants.  Bearded irises, as higher plants, have an alternation of generation from gamete-producing gametophytes to dry tolerant sporophytes.  There is a double fertilization, the first producing the zygote and the second producing the endosperm.  When you make a cross you are adding hundreds of microgametophyte plants - the pollen - onto the stigmatic lip of the sporophyte. Less than 100 have a chance to succeed.  Each pollen grain responds to the sugary solution on the stigmatic lip to grow, as fast as possible, a pollen tube down through the style arm and perianth tissues to the central placenta tissue of the three chambered ovary, each with its double row of ovules. You can cross section an iris ovary and take a look for yourself.  Growing this microscopically thin tube takes about eight hours to reach the ovules in the ovary.  The pollen tube will grow through the short ovule stalk into the micropyle opening of the ovule that is a macrogametophyte plant.  This allows the gamete (2N) sperm nucleus to unite with the ovum, the gamete (2N) egg, to produce the (4N) zygote.  All of the protoplasts that develop into chloroplasts come from the ovule and none from the pollen grain. The pod parent provides all the chloroplasts that power photosynthesis and plant growth and vigor.  The zygote divides and develops into the multicellular new sporophyte plant embryo that is attached to an endosperm of stored food inside the seed.  The endosperm comes from the second fertilization when the second pollen tube nucleus enters the ovule and unites with two polar cells in the ovule to produce triploid (3N) cells in diploids and hexoid (6N) cells in tetraploids. The endosperm serves like a yolk sac that nourishes the germinating embryo. Only one pollen grain will doubly fertilize one ovule producing one embryo with its attached nutrient-rich endosperm.  (Processed white wheat is all endosperm.)  The developing seed coat covering comes from the sporophyte parent, while the embryo with its endosperm comes from two gametophyte parents.  As you can see, this is quite different from the reproductive process in diploid humans.  However, the end result is the same, two gametes unite to produce a zygote, doubling the chromosome number.

He and She.  Irises are neither he nor she, but HE AND SHE, being functional hermaphrodites like earthworms.  Both sexes are housed in one plant.  Usually, they are pod and pollen parent fertile, but sometimes only pod fertile, pollen fertile, or infertile.  Feel free to name irises with the first name of either males or females like ‘Clarence’ and ‘Suky’.  If you use first and last name, and they are living, you need a signed, consent letter from them, or if recently deceased from a first of kin to send to the AIS registrar.  Naming irises to honor friends, family, and celebrities gives real satisfaction, and many like ‘Edith Wolford’, and ‘Beverly Sills’ have won AIS awards and been commercial successes.  An excellent cultivar sells itself, yet a good name can help.  Names can define traits, such as ‘Sky and Sun’, sky blue with bright sun-like yellow beards, and the deep purple ‘Grape Harvest’ that smells like concord grapes.  Short names are good for dwarfs as they have smaller writing surfaces on their fans.  

FabulousFlower.  Long ago, irises were called swordlilies for their sword-like foliage and flags for their three upturned standards and three down arching falls.  (Standards are flags flown up above a castle and falls are banners hung down in front of a building.)  Each petal, as a modified leaf, has a broad blade and a basal claw that is narrow in standards and broad in falls.  Down the center of the fall’s claw is the beard made of an elongate caterpillar-like tuft of thin, multicellular epidermal hairs that add surface area to diffuse volatile oils and their dissolved perfumes.  The standards arch over to form a domed space where these fragrance-laden oils can be trapped and concentrated.  The insect pollinator sees the broad petals from a distance and the contrasting beard as it draws nearer.  Then, it detects the fragrance that increases as it lands on, or by, the beard and crawls down to the base of the fall’s claw where the cup-like nectaries offer a drink of sugary liquid.  On each side of the beards are the hafts where pigmented veins point the way to the two nectaries. Insects and hummingbirds that can see in the ultraviolet range can visualize the UV patterns in the flowers that serve as guidelines to the nectaries that are invisible to mammals like humans.  Beyond the beard, on each side of the arching fall, are the two shoulders of the fall. 

My mother said the iris flower is like a cathedral with three petals lifted up to the Trinity and three petals turned down as our body, mind, and soul.  She said each of us was the Creator’s cathedral where we were granted our lives.  She often told me to do nothing that would harm my cathedral.

It is a challenge to describe the beards, its colors and their distribution. The beard can be all one color or solid white.  No one has yet produced a solid, inky black beard on a white flower.  The base or throat, middle, and end can be different colors.  The beard hairs are often white or pastel at their bases and tipped darker or a different color.  I admire white-based hairs tipped violet as in MDB ‘Lotta Dotta’.  There can be a middle section of the hairs that is darkly pigmented sandwiched between the lighter end and base.

There may be more pigmentation, or a different color pigmentation, at the base of the standards and the falls.  The standards may have different pigment patterns on each side and some falls have color on their bottom sides like our ‘Sunny Butter’.  There can be darker pigmentation down the center of the standards or falls called the midline.  In plicatas, a line across the ground of the falls was called a “belly line”.  It now occurs on beautiful, modern cultivars.  There is a dominant modifying gene with dosage effects for this dark line crossing the white or pastel colored ground.  If this line were wide enough, it would make the two ground areas look like a cartoon character’s eyes.  In SDBs, a white or light pastel midline often dissects the darkly pigmented central pumila spot.  At the end of the beards extending down the falls can be a light spike that is a dominant trait that is passed on to its offspring.  If you break off a fall and a standard, you will have a better view of these color patterns in the standards, falls, and style arms.

The male parts of the flower are its three stamens composed of elongate anthers and supporting filaments.  The stamen with its anther has two parallel pouches with thousands of pollengrains and looks like a slender double popsicle on a single stick.  The female parts (ovary, style, and stigma) together are called the pistil – “the pistol packing momma”.  The ovary below is connected to the other flower parts by an elongate perianth tube to the six petals and three inner stylearms.  Each style arm arches upward and outward with its horizontal, upturned stigmaticlip extended across the widest portion and topped with two, tapered, thin crests.  There is a slight groove up the middle of the style arm on its out-facing surface where the stamen lies protected.   Each style arm and its crests act like umbrellas shielding the pollen grains of the anther.  Even in a light, driving rain, one style arm with its protected stamen may have dry pollen.  The style arms are beautifully sculptured with an internal midline ridge that is often more darkly pigmented.  The lateral sides are thinnest on their edges and the whole structure tapered down to its base.  The edges are often a different color creating a beautiful pattern seen from above if the standards are erect or open and not closed.  There is a “rule” that a flower with open standards should have an internal, beautiful pattern or lose points.  A self with petals and style arms, all of one color, would not need such an inner color pattern to improve its beauty.  This rule dictates that selfs must have closed standards. With increased substance, width, and ruffling many modern cultivars of necessity have erect or open standards.

Count Your Genes. Genesareparticulate, not mixed as titers in the blood as proposed by Charles Darwin, who had copies of Mendel’s papers in his study, apparently unread or unappreciated.  Also, Darwin obtained 3 to 1 ratios of traits in his own pea crosses, yet died not understanding that genes are particulate.  A linear location, LOCUS, plural LOCI, on a chromosome is the gene for a specific trait. In plant cells, most genes are in the linear DNA of the chromosomes in the nucleus; however, fewer additional genes are in the cytoplasm in the cyclic DNA of mitochondria and chloroplasts. Genes can be: 1. descriptive genes for recognizable traits, 2. modifying genes that can alter the degree of expression of the descriptive genes - may have dosage effects being most effective at four doses, 3. regulatory genes - HOMEOBOX genes that can switch on and(or) off a cascade of expression of many different genes, 4. jumping genes, TRANSPOSONS, inserted into plant cell DNA by retroviruses, and 5. cytoplasmic genes in the mitochrondria and chloroplasts.  Cytoplasmic genes of the chloroplasts do not follow the genetic laws of Mendel.  They are pod parent - maternally - inherited. Variegated foliage must be in the pod parent to obtain it in the offspring.  Most likely, other modifying genes in the chromosomes give a dosage effect so that only 5 to 10 % of the seedlings have variegated foliage.

Allele Appeal.  At each separate locus, it is possible to have only one, or two or more different alleles that can express different traits.  ALLELE is an essential term in genetic discussions.  The allele is the linear strand of DNA at a specific locus as the address of a specific trait.  Factor is still used to denote just the trait, like the tangerine factor; yet now, factor usually means a molecule with a specific physiological action.  The genotype (tttt) is the alleles at a locus on the four similar chromosomes in tetraploids, while the phenotype (tangerine beards or pink petals) is the expressed traits in the seedling. One dominant allele can prevent expression of three recessive alleles.  There are several dominant gene loci for yellow (Y) carotenes.  We say that yellow is dominant over the recessive tangerine (lycopene) allele, yet a flower can have a blend of yellow from xanthophylls mixed with red-orange lycopene to produce yellow-orange.  If a cultivar has only lycopene, it could be a spectrum red or used in crosses to intensify and produce one.

In Stitches.  At the locus named plicata, there are at least 8 different alleles for different expressed traits, with only 4 being present in a tetraploid; theoretically, in a cross, you could have all 8 in both parents. First, there is the “no pattern” dominant allele (Pl) that produces a self with anthocyanin pigmentation in the petals and style arms.  To be fully expressed, there must be four recessive doses of the allele, or it occurs only with other recessive alleles.  Some recessive alleles can express their traits mutually, like in a pecking order, pl > lu > gl.  Plicata (pl) has anthocyanin in “stitched” borders and around and in the beards, yet none in the central GROUND of the falls.  Luminata (lu) has anthocyanin reduced in veins and around petal edges and none in beards or around beards.  Glaciata (gl) has absolutely no anthocyanin in the flower.  There are minimal plicatas showing reduced anthocyanin in their borders, yet the style arms may be dark violet, and those like the white ‘Laced Cotton’ with no plicata pattern that with test crosses show it is a plicata. The genotype, (lu lu gl gl) produces a LUMINATA PATTERN, (lu lu pl pl) produces a FANCIATA PATTERN (described below), (pl pl pl pl) or (pl pl gl gl), etc. can give a PLICATA PATTERN, and (gl gl gl gl) a glaciata phenotype. In their flowers, glaciatas have no anthocyanins or their precursor molecules that turn violet in dilute HCl acid solution.  In the past, (pl subscript a) meant “all white” for glaciata, then called “ices”. This notation is both difficult to type and a misnomer as glaciatas can be white plus any color or color pattern of yellow, pink, red, and orange.  In the past, some of these patterns were called “fancies”.  I single out as “fancies” only luminata-plicatas (lu lu gl gl) as the fanciata pattern having light veins and edges and an anthocyanin wash over the falls and anthocyanin around and in the beards.  A modifying gene determines, with dosage effects, how very dark or very light the wash will be.  All the cultivars with the luminata pattern I have studied with test crosses had to have two doses each of luminata and glaciata alleles.  The (lu) allele may produce just the lightened veins, and (gl) the rest of the luminata pattern.  I have yet to find a cultivar that I felt strongly was a four-dose luminata.

Splish Splash.  Variegated flowers have a transposon inserted into the host chromosome that deactivates the single dominant allele at the plicata locus (Pl pl pl pl) so the three recessive plicata alleles can be expressed. When the transposon jumps off the (Pl) dominant gene reactivating it, the cells from its division produce anthocyanin pigmentation with the (Pl) self pattern. This jumping on and off creates the splishes and splashes of white or pastel and anthocyanin pigmentation. Bryan Spoon selfed ‘Millennium Falcon’ and got ‘Alessandra’s Gift’, the most vigorous variegated we grow, a rebloom carrier producing tangerine beards. It has two shades of jade in splishes and splashes plus a 2^nd variegation of violet wedges lined white.  Michael Sutton’s ‘Breaking Point’ has a variegated flower plus a nice space age adornment and reliable rebloom.  One of the best parents for variegated flowers is the 36” tall ‘Brindled Beauty’.  

Luck Be Mine.  My mentor, Dr. Charlie Nearpass, was convinced that to be a successful iris hybridizer you needed to learn all you could about their genetics.  He told me how he planted about 1,000 seeds from a single cross he made to try and express together three recessive traits that had a probability of about 1 in 500.  He was unlucky and got none.  Allan Ensminger spent forty years to produce a cultivar to honor his wife, ‘Gladys My Love’, that required expressing in one cultivar, three different recessives.  He also worked many years to produce a good garden plant with variegated flowers plus variegated foliage.  He got several, but none met his standards for introduction. Variegated foliage has a portion of its blades that are white with no chlorophyll, so they have reduced vigor.  Allan said his greatest successes came from following the lead of his seedbeds where he appraised over 250,000 seedlings.  He was trying to make a red, white, and blue plicata to name ‘Our Flag’ and produced the line that has led to most of the beautiful modern cultivars with variegated flowers.  Brad Kasperek added greatly to this line and won a Wister Medal for his variegated ‘Millennium Falcon’.  If your seedbed presents you with a new hybridizing goal, go for it.  If you learn how to inbreed, you can reach difficult goals in two to three crosses in less than ten years.  If you are both smart and lucky, you may reach your goal in one cross in two years.  A single inbred cross (selfing, sibling, or back on parents) can increase a hidden recessive allele from two to four doses allowing its phenotypic expression.  If there is only one dose, two inbred crosses can increase it first to two and then to four doses.  Relying only on first cousin inbreeding requires many more crosses and seedlings to go from one to four recessive allele doses with phenotypic expression of the trait.       

How to Cross.  Make carefully planned crosses designed to reach a specific goal.  If you can make the cross only one way, the more vigorous cultivar should be the pod parent that provides all the chloroplasts.  The best pod parent flower is a newly opened one.  It needs to have stigmatic lips moistened with its sugary solution that induces pollen grains to dehisce - burst open.  An older flower will provide anthers with their two linear pouches opened, exposing the puffy, mature pollen.  Anthers from a newly opened flower may not work; and once the stamen is removed, the pollen in the anther makes no further development and remains immature.  Gently remove all three stamens from the pod flower by grasping the thin, basal filament of the stamen and not the anther.  Place a Postem ® paper, cut square into a 5-cm plastic Petri dish, and with a pencil write date, name or seedling number, and goal.  Place the dish with the stamens in an 8 ½ by 11” tray covered with the thick piece of paper on which you record your crosses and pertinent notes.  The thick 20 weight paper (three hole punched) will shade the closed dishes that can heat up from the direct sun, and cause the pollen grains to die.  Place a stamen, puffy side up, in your palm and with your best hand grab with tweezers the anther in its middle.  With the puffy side down, apply pollen to all three or just one of the stigmatic lips.  The pollen tubes growing from one stigmatic lip can reach all of the ovules in the three chambers of the ovary.  Use an up stroke followed by a down stroke.  Do not repeat any swipes or pollen can be removed.  You can use the thumb and forefinger of your other hand to hold the style arm crest and gently pry open each stigmatic lip.  Wipe clean your palm and tweezers tips after each cross.  With pencil, write on a flexible plastic key tag, the date, cross number, and pod and pollen parents.  Tie this tag on the stalk below the flower. This tag will follow the cross.  When the seeds are planted, it can be secured with the cross sign wire or through a hole in the vinyl tag and will last several years.  If rain is predicted within two hours after you have made a cross, cover the flower with an open Ziploc ® bag with a corner cut out so heated air can escape. Record your cross using the “ladies first rule”.  Give the pod parent times (X) the pollen parent. Transpose with permanent ink or pencil, not ball points, all this cross information to bound record books.  Keep them in a dry, secure location.  For the computer literate, do not trust your hard drive or backup discs, rather rely on a laser printed hard paper copy for your permanent cross record folders.  Someday they may be kept in the AIS library.  Never take your precious record books into the yard or on a visit.  I make a second list of each year’s crosses on thick sheets written in permanent ink that are held in a clipboard or in a three ring notebook that can be taken into the yard or on a visit to discuss with others.  A laptop with your photographs is a great way to share your successes with other hybridizers.  A planned program of your best seedlings will be appreciated.  But let them share theirs too, you don’t want to be an “iris borer”.

Long Live Pollen.  Pollen, in 5-cm closed plastic Petri dishes in cold storage (45 F), will be viable up to six weeks and some survive to three or four months. You can save SDB pollen to cross on TBs a month later.  To insure pollen longevity, store your closed dishes with stamens in the refrigerator except when you are out hybridizing.  Frozen, in folded pieces of plastic film or gelatin capsules, pollen lasts over a year.   However, once thawed the pollen must be used in a few days and not refrozen. 

Pod Care and Seed Planting.  If you gently remove the two spathes or leaf-like valves at the base of the flower after you make the cross, aphids can not hide under them from predators like beetle larvae.  Aphids can harm the developing pod. You can cover the pod, once the flower parts are fully dried, with a loose, porous fabric secured at the stem with a twist tie, so verbena bud moths can not burrow into the pod and eat 10-30% of the seeds. The fertile ovary will swell into a pod in weeks, and in two months will turn tan, crack open, and the seeds fall out.  Avoid this by harvesting the mature pod and removing the seeds to a labeled paper lunch bag that is fully porous to air, but not impermeable plastic bags.  Double fold and crease the bag edge to ensure the seeds will stay inside and store upright in a cool, dry location in a larger open paper bag.  I arrange each bag with its seeds from one pod as to goals and renumber them,such as #2011-1.  This way, seedlings for the same goal will be close together for crossing.  I record in the permanent record books the original cross number as on the field record sheets.  In TBs, the pods may be as big as walnuts and have up to 100 seeds, in dwarfs, pecan sized with up to 50 seeds.  Plant directly into seedbeds in late October through early November at least 3 inches apart, in rounded depressions ¼” deep or twice the seed thickness, then covered with a little soil and gently patted flat. A ¼” layer of pine mulch can prevent rain from dislodging the seeds to the surface.  Plant seeds in pots - at least one gallon size - 1-2” apart and cover with a ½” mulch of short pine needles.  With pots, usually the seeds that do not germinate the first year are discarded when you transplant the seedlings; but you can hold the pot for another year or more and transplant the remaining seedlings that germinate.  Do not let the seedbeds or pots dry out.  In northern zones, the pots need to be in contact with the soil and mounded with sand.  You can cover the seedbeds and pots with wire to keep out animals. In zone 6b, seedlings begin coming up in early April. When the seedlings planted in pots have 4-6 leaves, replant them in seedbeds at least 6” apart.  In soil, seeds can germinate for up to 5 years.  You may get 40-60% germination the first year and 10-20% more the second year. Seedlings that come up in seedbeds the second year can not compete with larger seedlings that came up the first year and to survive need to be transplanted to a separate seedbed. 

Stratify?  You may want to try moist stratification in a refrigerator of the seeds from a cross by placing them in a porous fabric bag.  This method was developed by John Weiler and perfected by George Sutton.  I have used it often, but prefer planting seeds directly in a seedbed. You can make closed bags for the seeds from a cross with a 6” square of muslin labeled with a permanent marker for the cross.  Purse the edges and tie tightly with a twist tie.   Place the bags with securely enclosed seeds in a cut off milk bottle as a low tray.  Fill the tray to cover the bags with water and store in a cool place.  Rinse the trays daily for 7-10 days to remove germination retarding chemicals like abscissic acid. Pour off most of the water and refrigerate them below 50 degrees F for 90 days of vernalization. A maximum-minimum thermometer in the coldest part of the refrigerator can prevent freeze damage. The bags may need added water about once a week to stay slightly moist.  Check them at 70 and 80 days for emerging roots and before the roots elongate and penetrate the muslin.  Sutton uses sections of stockings with a finer mesh.  You may get nearly 100% germination.  However, the procedure has lots of chances for failure and is very difficult to master, especially planting the brittle embryos.  Try it first with some less valued crosses or “bee” pods.  

Uninventive incentives.  Dominant genes of cultivars usually express wild type traits from species that created the hybrid.  Modern traits for flower form, like wide and ruffled petals, come from recessive genes and their modifying genes. To be expressed, these traits from recessive genes must occur in four doses in tetraploids. In diploids, the Punnett square for the gene frequencies of Aa (dominant plus recessive allele) X Aa gives a potential of 1 in 4 offspring as aa expressing the recessive trait and three expressing the dominant.  In tetraploids, the similar cross of AAaa X AAaa with a Punnet square predicts 1 in 16 aaaa.  However, yields are nearer to 1 in 36, nearly a ten fold increased difficulty to express recessive traits in tetraploids compared to diploids.  AIS judges who place flower form above all else in a cultivar in competition for awards add decades of hybridizing efforts for a new form, color pattern, or color break to be acceptable to them as “a good garden flower”.  We must also ask if such “modern form” can create oversized, heavy flowers that with rain can hardly open or close without rotting.  Maybe, as one British author suggested, the natural, graceful lines of the wild iris flower are being lost. Those who write the AIS handbook guidelines need to ask, “Is this a wise incentive?” Also, should the 3 bud terminal goal that can lead to undesirable flower bunching be so highly valued, and is the seven buds per stalk minimum requirement for TB seedlings narrowly restrictive?  Many good seedlings do not appear at shows for the general public because of this “bud counter’s rule”.  Bud counts of 7 or more should never be used to rank higher a seedling of less overall quality.  Bud count is just one trait, and one that is highly dependent on growth conditions, climate zone, and seasonal influences.  We transplanted about a hundred TB cultivars from our gardens in Virginia to the Biosphere II site in Oracle, AZ and watched them growing there for three years.  In general, the cultivars with 5-7 buds in the East had 7-11 in the West and had bigger flowers with more ruffling.  Some like ‘Silverado’ were excellent in both the East and the West.

Two Pigment Paints.  Most pigmentation of the flower is in the upper and lower epidermal cells.  The water-soluble violet, blue, maroon, and cardinal red anthocyanin pigments are in the central fluid vacuoles. The lipid soluble yellow xanthophylls and carotenes plus pink, red, and orange lycopene pigments are in the cytoplasm. (Lycopene - a carotene - has no six-carbon rings on its two ends and does not dissolve in alcohol as do yellow carotenes and xanthophylls.)  I call the water-soluble pigments ANTHOCYANINS (or “CYANINS”, abbreviated AC) and the lipid-soluble pigments CAROTENES (or “CAROTINS”, CT).  There are different genes for pigment expression in the beards. A SELF (SF) can be one color with beards a different color.  A COMPLETE SELF (CSF) has beards of the same color.  Most of the color patterns in anthocyanins are also found in carotenes.   Anthocyanins and carotenes are independently superimposed onto one another as if painted on two separate, overlaid sheets of transparent plastic.

IA IC.  There is a dominant inhibitor of anthocyanins (IA), and one for carotenes (IC) at a separate locus.  {I add an A to the I, so I will not have to write (Is) in the next sentence that is the word is.}  (IAs) inhibits anthocyanin only in the standards producing amoenas, classically with white standards.  As hybridizers, we know all the carotene pigment patterns can occur, so a dominant anthocyanin amoena can have white as well as yellow, red, or orange standards and be bicolors.  The IA gene by inhibiting anthocyanin pigments in standards, style arms, and falls is responsible for most white, yellow, pink, and orange selfs.  One dominant dose can remove most of the anthocyanin.  However, you will know these cultivars are not glaciatas as there is always a tiny bit of anthocyanin pigment at the base of the falls.  Also, dilute HCl acid turns the flower violet, yet does not in glaciatas with no anthocyanin precursor molecules.  With IA inhibition, the anthocyanin is chemically cloaked but still there, while in glaciatas there is absolutely no anthocyanin or its precursor molecules.  It appears that this IA gene has a dosage effect and with four dosages white is whiter and the carotene pigments are purer and less greyed with the light lavender blue of anthocyanins.  Often this light lavender blue wash with low dosages of IA is removed after a few hours of exposure to sunlight as in Lloyd Zurbrigg’s ‘Immortality’ that then turns into a pure white.

Sweet Amoena.  Amoena - means pleasing - was once just recessive amoena in bearded irises with difficulties for its expression in tetraploids; yet it came with smooth hafts.  Paul Cook crossed yellow I. reichenbachii with TB ‘Shining Waters’ producing ‘Progenitor’ and by a series of back crosses to TBs secured the IAs gene (dominant anthocyanin inhibitor for standards only) producing ‘Whole Cloth’. He discovered a plicata-like, yet solid anthocyanin border pattern, and named it for his wife, ‘Emma Cook’, the EC pattern, an IAs variant as in ‘Queen’s Circle’.  The IAs gene is a good example of descriptive gene with DOSAGE EFFECTS. (A term with a long history is “NEGLECTA” meaning a bitone of violet-blue anthocyanin pigments with the standards lighter than the falls as in the lovely ‘Mystique’)  Four doses of dominant (IAs) produces an AMOENA with no anthocyanin in the standards that can be white, yellow, pink, peach, or orange. Three doses (IAs IAs IAs ias) give a SLIGHT BITONE.  Two doses gives a BITONE with lighter S. One dose gives a bitone with slighter lighter S. than the F. (as a violet-blue NEGLECTA), and four doses of recessive (ias) gives an anthocyanin SELF.  I propose a gene (A) at a different locus for dominant anthocyanin self that is darker and smoother than the plicata (PL) self.  Crossing a plicata with all recessive genes on a self may remove all (PL), and then the (A) will express a darker, smoother violet self.  This also works for anthocyanins like cardinal red and spectrum blue.  Amoena can be added to other patterns like plicata expressing the plicata pattern only in the falls.

Top Amoena.  Reverse amoena is when the anthocyanin pigment is more pronounced in the standards than in the falls.  It appears to be at a separate locus and this trait is dominant with dosage effects.  Many are trying to reach the goal of solid black standards with white falls and spectrum red beards.  This seemed a distant goal for the regular dominant amoena pattern, but Joe Ghio showed it could be done with his gorgeous ‘Starring’.  Keith Keppel won the Dykes Medal with the violet-blue reverse amoena ‘Crowned Heads’, but he may have topped it with his orange bearded ‘Friendly Fire’ and Wister Medal winner ‘Wintry Sky’.  There are many beautiful color patterns like yellow and brown in reverse amoenas.

Flower Power.  SUBSTANCE is the thickness, turgor, and strength of the flower parts that supports them in wind and rain. When frozen, this substance disappears and the petals lose their whiteness and are translucent and drooping.  TEXTURE is the surface of the flower parts like velvety falls that give them multicolor, shining sheen. DIAMOND DUSTING or GLITTER is produced by the raised epidermal cones acting as prisms. GLITTER can appear white, golden-yellow, or pink. SILVER LINING, produced by epidermal ridges, creates shining lines on petal edges as in ‘Sky and Sun’. The color white in irises is produced by the ability of the epidermal cones to produce a full spectrum of light as big enough droplets of atmospheric water make white clouds.  A frozen flower shows no white pigments in any pattern.

Fringing and Bubbles.  Lace (petal fringing) is variable. Lace is neither dominant nor recessive, coming from either parent and may require modifying genes with dosage effects to be expressed.  Lace can be slight toothed crenulations, pointed fringes, bubble lace as small, raised hemispheres, or even rare, long and pointed as in ‘Feathered Friend’, like in laced tulips.  Some older laced cultivars were cold tender and prone to bacterial soft rot.  These undesirable traits have been bred out of modern laced cultivars. Lace used to be restricted to pastel colored cultivars like ‘Feature Attraction’, but now heavy lace is appearing even in violet blacks like ‘Hollywood Nights’.  Nicely laced rebloomers are rare, suggesting a good goal. 

Ruffling and Fluting.  Heavy ruffling and wide petals are hallmarks of modern flower form and considered by some hybridizers and garden judges to be required for introduction. I believe that smooth edged petals called TAILORED are also beautiful. Tailored MDBs and SDBs with narrow blades and petals are delightfully petite and dainty.  Some believe the petals of even these dwarfs must be wide and ruffled to be worthy of introduction.  Graceful, sinusoidal RUFFLING can be lovely.  I prefer it to jagged, irregular ruffling.  Ruffling, like in a Dutchman’s collar or roller coaster, is called FLUTING.  Heavily ruffled and laced, wide flowers with heavy substance require especially sturdy stalks and strong anchoring roots.  It is encouraging that a cultivar with moderately wide falls like ‘Paul Black’ was awarded the Dykes Medal.  It makes a commanding presence in the garden with its great, sturdy stalks and beautifully ruffled dark purple blue flowers with contrasting orange beards.     

Flowers and Flat-tops.  Standards can be domed and CLOSED at the top hiding the interior, ERECT to slightly show the interior pigment patterns, OPEN completely, or even OUTSPREAD, pointing outward.  Falls can be horizontally flared, FLARED in a waveform, slightly arched, ARCHED, or UNDERCURVED (tucked under).  Charlie Nearpass had a system of five stars for evaluating his seedlings.  He only gave five stars to one seedling he named for his daughter, ‘My Katie’; a tall bearded with wide, beautifully flared falls.  Recently, some have tried to impose their “personal rule” that tall stalked TBs should not have flared falls, as they shouldbe viewed from a considerable distance where arched falls show more color.  I prefer viewing a clump directly in front of it so you look down on all the falls, flared or arched.  The standards and falls of irises are all petals, and they have no sepals.  Bearded irises and daylilies lost the homeobox gene for sepal development while doubling the homeobox regulatory gene for producing petals.  In irises, the regulatory gene for one set of three petals mutated to produce upturned standards.  FLAT-TOPS have no standards and six falls, and no stamens.  All flat-tops are sterile, but can make great garden plants, and some are reliable rebloomers. Iris flowers are bilaterally symmetrical coming from two cells each producing ½ of the flower split down the middle of one fall and between the two falls on the other side.  A point mutation at later divisions produces CHIMAERAS (or chimeras) with a petal or streaks of a different color or white.  Some chimaeras have ½ the flower white and the other half pigmented.  (Rarely, this happens in animals as in a cardinal that is white on one side and normal red colors on the other side.) 

Crossing for Borders. Homeobox genes control different realms (areas) of the flower turning on and off many different genes.  A semicircular delineation of the two major realms of the falls, the broad claw and blade, occurs in some cultivars at the end of the hafts and beards and the rest of the fall just before the lateral shoulders where the fall arches over.  (Some cultivars have deeper pigmented, elongate spots on both shoulders called THUMBPRINTS.)  This broad basal claw area has sub realms – hafts and beards – most likely under different homeobox regulatory control. The fall blade has concentric realms for control of multiple borders surrounding the fall center ending in dark HAIRLINE EDGES as in ‘Splashacata’.  One carotene border pattern is the HALO, a recessive trait perfected by Dave Niswonger, as in ‘Halo in Rosewood’ or in Bryan Spoon’s ‘Bright Morning Star’.  Borders with no anthocyanin pigment is an UMBRATA (shaded as by an umbrella) pattern, with anthocyanin only in the central area of the falls. This umbrata white or carotene border can be narrow to wide. Test crosses show that a modifying gene with dosage effects may control the width of this border.  Hybridizers are approaching umbrata patterns so wide in bearded irises that the central anthocyanin area forms small dark spots at the end of the beards resembling the signal spots in aril irises.

I’ll Be Back.  Bearded iris REBLOOMERS (RE) of similar form, color, and pattern may eventually replace look-a-like SPRING BLOOMERS in many gardens.  The buying public appreciates iris cultivars that extend the bloom season for two weeks or more into late summer and fall.  Beardless and a few bearded cultivars can be REPEATERS (RP) putting up additional stalks in June or July. Rebloomers have lost wild type, dominant traits by selection of four doses of recessive alleles: 1. LOSS OF SPRING ONLY BLOOM CONTROL. No rebloom is possible without four doses of recessive alleles of the gene locus that is called Frigida in Arabidopsis.  Cultivars with these four recessive doses, yet do not rebloom in any zone, that can produce rebloomers when crossed on rebloomers are called REBLOOM CARRIERS (REC).  Fall rebloom (FRE) is coupled with earlier growth and stalk formation in the spring when late frosts may occur. Rebloom in the fall will be at a similar photo-period (hours of sunlight) as in the spring.  2. LOSS OF PHOTO-PERIOD CONTROL.  Any of the dominant genes that produce photo-period control in four recessive doses can add shorter day, summer and longer day, later fall rebloom (SFRE). 3. LOSS OF SUMMER DORMANCY CONTROL.  Four doses of recessive dormancy alleles will remove the dominant summer dormancy controls allowing better midsummer rebloom in late June and July.  If all 3 traits are 4 dose recessives, you can have MULTIPLE (3 or more) rounds of blooming and reblooming occurring throughout the growth season, or ALL SEASON (ASRE), for your climate zone.  Your growth season may be down to 6 months in zone 4 and up to 12 months in zone 9.  Our all season rebloomer BB, pink and peach with tangerine beards, ‘Midsummer’s Eve’ sometimes puts up stalks with the MDBs and continues all season until the hard frosts of late November.  It is from the cross, ‘Immortality’ X pink ‘Enchanted World’ and shows that ‘Immortality’ carries two doses of recessive tangerine factor allele.  There are only about 25 such all season rebloomers, and beginning hybridizers should secure the best of them for their collections.  It is best to cross all season rebloomers on one another or cross them back on their parents or on siblings to keep all four recessive allele doses for all three of the required traits.  Rebloomers need support from high doses of dominant genes for vigor, increase, and resistance to bacterial soft rot, other diseases, and pests.  Without extra watering in prolonged summer droughts and added fertilizer in mid summer, late summer and fall rebloom may be minimal.  This limitation does not apply to some historic rebloomers like ‘July Sunshine’ that can rebloom without extra watering and fertilizer.  This valuable trait needs to be added to modern rebloomers.  To record a cultivar as reblooming in your zone it must at least open the top flower before a freezing frost hits the stalk.  Some rebloomers are SPORADIC, meaning they seldom rebloom.  This is not a reliable rebloomer, yet it can be used in crosses as a rebloom carrier.  Rebloomers that are reliable only in zone 8 and 9 when crossed on rebloomers from colder zones, 4-7, can produce offspring with reliable rebloom in these colder zones.    

Lycopene Scene.  Pink, peach, red, yellow-orange, and orange are produced by the carotenoid pigment, LYCOPENE (LP). This recessive allele (t) for lycopene expression in four doses (tttt) produces the “tangerine factor”.  If only one yellow dominant carotene gene (Y) is present, no lycopene is made.    Orange is probably a combination of lycopene with yellow xanthophylls.  If no yellow pigment is present as in some beards, the color is a true spectrum red (RHS 43A) as can be seen in the beards of ‘Signal Red’ and ‘Code Red’, whose color can vary with cultural conditions.  If any red color remains after removal with alcohol, even deep in the beard throat, then the genotype is (tttt). (Test crosses with cultivars with expressed lycopene only in the beard throat crossed on cultivars with lycopene pigmented petal and beards can produce similarly pigmented seedlings.)  A SDB sibling cross I made produced an MDB sized glaciata ‘White Ice’ with no anthocyanin and a cardinal red SDB seedling.  This showed that cardinal red (RHS 53A) is an anthocyanin pigment and not due to any lycopene.  Combining cardinal red anthocyanin with red lycopene in the petals produced a good flag red color (RHS 46 A/B) in our TB for 2013, ‘Red Hot Momma’.  The IC gene, dominant inhibitor of carotene, has a dosage effect.  Four doses (IC IC IC IC) make white flowers. Genes for lycopene expression in the beards are different so they can be red-orange on a pure white flower as in ‘Christmas Rubies’.  Four doses recessive (ic) give the most intense pink pigmentation as in ‘Ovation’.  There are many paths to producing the first signal or spectrum red (RHS 43A) self. The challenge is to obtain a cultivar with lycopene expression in the epithelial cells of the petals that is as intensely spectrum red (43A) as produced in the multicellular beard hairs of a few cultivars. A difficult pathway to a spectrum red complete self is with recessive glaciatas that would produce a translucent, luminous red color.  Progress with orange and red glaciatas could be quite rewarding.  However, the inbreeding required with recessive glaciata is a challenge to the hybridizer.  The secret may lie in finding other sources of recessive glaciata as when crossing two sky or medium blue cultivars with red beards.

Buz Lightyear.  Space age (SA) irises have adornments as petaloids at the end of the beards.  Some have two, one above the other, on each fall.  They can be pointed HORNS (HN) with and without beard hairs, elongate SPOONS (SN) with narrow blade-like tips like a teaspoon, elongate FLOUNCES (FN) with broader ruffled ends, bouquet-like POMPONS (PN) on thick claws, to the ‘Nth Degree’ by Tom Burseen, and beyond.  In space agers, homeobox genes for directing formation of the falls have been turned on in thick masses of cells at the ends of the beards to produce three new modified fall petals or petaloids. A pattern such as the border recessive halo, EC dominant border, or plicata is similar to the falls extending down the new “SA petal” (my term) as seen in ‘Momentous Occasion’.  Earlier, other hybridizers had this Space Age trait appear in their gardens; but it was Lloyd Austin who championed them.  Many of his introductions are retained in historic collections.  His initial cross was a selfing of Sidney Mitchell’s ‘Advance Guard’, and some early SAs had falls with unattractive middle crimping and vigor problems.  Now SAs, like those of Lloyd Zurbrigg, Jim Hedgecock, George Sutton, and his son Michael Sutton, lack such problems and can be great garden plants. Three Space Agers, ‘Thornbird’, ‘Conjuration’ and ‘Mesmerizer’ by Monty Byers, won the Dykes Medal.  A good SA parent that carries rebloom is Manley Osborne’s ‘Sky Hooks’.  Crossing SA X SA can yield diverse results yet also deformed monsters.  The SA gene is dominant, so use the most vigorous parent as pod parent, usually the non-SA.  Ideally, a cultivar should have all flowers with the same kind of SA petal. The full development of the SA petals is determined by climate and culture as seen in space agers such as ‘Thornbird’ that can have horns or spoons. The development of new SA cultivars has already reached amazingly unexpected levels.  Being dominant, SA petals could adorn any other goal.  Ben Hager believed adding space age adornments should give a “lift” - as to fly - to the beauty of the flower, as in the sky blue ‘Lady Sings the Blues’ by Jim Schroetter.  

Smooth Hafts.  Recessive anthocyanin amoenas have SMOOTH hafts lacking haft marks with darkened veins. I believe that the dominant wild type gene for this locus is HAFT MARKS that act as guides to insect pollinators to the nectaries at the base of the falls. This dominant may have dosage effects.  One dose would be haft marks beside the beards, two doses they extend into the shoulders or like a sunburst around the beards, three doses they extend half or more down the falls as in ‘Panama Hattie’, and four doses, the whole falls as in Ben Hager’s ‘Anything Goes’.   Another explanation is that a modifying gene with dosage effects is involved.  Haft marks were once avoided like the plague, but now can be beautiful.

Lotta Dotta.  I propose that at this haft locus are recessive alleles for anthocyanin pigmentation above the vascular bundles (LINES) and small spots (DOTS) between the bundles.  Having two doses of each you get the lines and dots (“speckles”) pattern of ‘Expose’ with its umbrata border. George Shoop’s ‘Fancy Tales’ is one of its ancestors.  Stitched plicatas can have anthocyanin borders that are solid, just lines, just dots, or both lines and dots.  I believe that the haft recessives lines and/or dots pattern has been superimposed on the recessive plicata pattern.  The unique ‘Splashacata’ out of plicata  ‘Purple Pepper’ has both lines and dots, but ‘Celestial Explosion’ has only dots, possibly with 4 doses of haft locus recessive alleles for dots. Placing on top of the plicata this line pattern we have dark veins running across the white ground as in our spider series such as SDB ‘Spiderman’ out of ‘Bordeaux Pearl’ X ‘Dinky Circus’.  We usually think of plicatas as having white grounds in their falls, yet it can be yellow, peach, and even yellow-orange as in the gorgeous Dykes Medal winner ‘Drama Queen’ and ‘Tuscan Summer’.  With his black plicatas like ‘Inside Track’ and ‘Oreo’, Keith Keppel may be conjuring up a spooky black plicata with intense orange ground.  Maybe, you will give a black plicata a spectrum red ground with an overlying spider web of black veins.      

Zonals, Sunbursts, and Whiskers.  There are color patterns where the anthocyanin is missing or reduced around the beards.  There appears to be two kinds of ZONALS.  The first zonal is where an area around the beard is white or pastel being completely without anthocyanin with defined, dotted, or serrated border. ‘Full Impact’ has such zonals in both the standards and the falls.  The second zonal has pigmentation that grades from very little to more as you move from the beards to the fully pigmented periphery of the falls as in ‘Victoria Falls’. This grading light zonal is present in many of the top awarded anthocyanin and carotene cultivars as it really sets off the beards.  Both types of zonals appear to be recessives with the first (zn) probably at the plicata locus and the second (z) may be at the (A) anthocyanin locus I have proposed. Another anthocyanin pattern is where the areas between the pigmented veins are wider and produce a white or pastel SUNBURST (sunspray) effect in a semicircular area around and beyond the beards.  These appear to be recessives as well, and there may be several kinds at different loci.  In SDBs, the anthocyanin pumila spot in the middle of the falls is dominant over not having this spot.  This PUMILA SPOT can have radiating pigmented veins forming dark WHISKERS extending out from the end of the beards as in SDB ‘Snow Tree’.  This whisker pattern in the center of the falls is rare in TBs like in my zone 8 rebloomer ‘Plum Pretty Whiskers’ that needs some improvements.  

Carotene Patterns.  Recessive carotene amoenas with white standards and yellow, peach, pink, or orange falls offer many challenges to the hybridizer, with white standards, spectrum red falls, and blue beards being the greatest challenge. Superimposing recessive carotene amoena on dominant anthocyanin amoena can produce black amoenas. The carotene pattern in yellow ‘Again and Again’ is similar to the anthocyanin pattern in ‘Suky’ and ‘Tall Ships’.  The carotene can be darker in the falls center as in Griff Crump’s lovely IB ‘Coral Chimes’ and for anthocyanin orchid pink in ‘Orchid Dove’.  A carotene border can be superimposed on an anthocyanin border to produce a brown or black border. Most patterns in anthocyanin can occur in carotene, superimposed or separate, yet the carotene patterns are more likely to be recessive.  Jean Witt and Lynn Markham expressed their belief that the anthocyanin pigment patterns could all occur as similar patterns in carotene pigments.  Our new knowledge of homeobox regulatory genes might explain this as these genes determine which of the two pigment systems are activated or deactivated in the various realms (areas) of the flower to produce the various pigment patterns.  Central to this controversy is whether there is an amber colored carotene that is not an anthocyanin pigment.  Pigment extraction and analysis is fairly easy and inexpensive, and such procedures could be useful for a truth seeking hybridizer. 

Heaven Scent.  A pleasant fragrance can add greatly to a cultivar.  Presently, the AIS registration form only asks you to check absent, slight, or pronounced and sweet, spicy, or musky. To me a “pronounced musky” smell would be unpleasant, and there are many spice fragrances.  I never met a bearded iris I did not smell and have found many other distinctive scents other than just sweet, spicy, and musky to describe them.  We have about 400 different smell receptors in our nasal epithelium and can distinguish about 100,000 different fragrances.  Earlier, there was an AIS fragrance robin ably led by Libby Cross of Region 4, and back then fragrance was considered more important.  Maybe the AIS registration form will be changed and allow us to write in grape, vanilla, chocolate, allspice, clove, rose, etc. for cultivar fragrances.  The genetics of fragrance seems to be dominant with dosage effects, so cross together the best scented ones.  Libby chose the best scented rose amoena I grew for her namesake, ‘Libby Cross’ that won the Region 4 Nearpass award for best introduced cultivar.  Our ‘Secret Santa’ and ‘Daughter of Stars’ have especially pleasant fragrances.  At our 2003 AIS National Convention a visitor in her 90s, in a wheelchair pushed by her son, stopped in front of a clump of my ‘Uncle Charlie’.  I gave her a flower to hold.  She put her nose into the flower and after a long pause she looked up at me and said, “This is how Heaven will smell”.  Most irises have unique fragrances.  Nearly blind at ninety-two years old, hybridizer Frank Jones was brought by a friend to our fall show.  When he was led up to the stalk of one of his own introductions, he smelled it and said with a knowing smile on his face; “This is my ‘Grape Adventure’ ”.    

X Files.  Here are some other useful hybridizing notes. Wide as well as long beards are dominant to narrow and short. Cross cultivars with widest and longest beards together.  Sturdy stalks are dominant to stalks that routinely fall over.  It may be better to save an exceptional seedling with this one recessive trait and make the cross to give it sturdy stalks.  Using a cultivar with just one dose of dominant allele for sturdy stalks will produce some good ones, and four doses will give all offspring with sturdy stalks.  Purple base foliage is dominant to lacking it.  Crossing two cultivars with PBF can produce seedlings with expanded distribution of the purple pigment.  Cultivars like ‘Opalescent Dream’ with spathes that stay green are rare.  This trait is recessive and you need to find another cultivar with it for your seedlings to have this trait. A point mutation in ‘Beverly Sills” changed this coral pink cultivar into a white cultivar that was introduced as ‘Beverly in White’.  Lace only in the style crests means the cultivar can produce laced offspring if crossed on a laced cultivar.  Cultivars that bloom earlier in the spring season is an indication they may be rebloom carriers, that do not rebloom, yet crossed on rebloomers produce rebloomers.  Crossing two rebloom carriers that do not rebloom may produce reliable rebloomers.  Two cultivars, each with only two doses for fall rebloom, may produce reliable rebloomers with four doses.  Multicolored (green, white, creamy yellow, and plum) variegated foliage cultivars produce foliage you can sell to florists for flower arrangements.  We need more vigorous cultivars by crossing the most vigorous pollen parents on multicolored variegated foliage pod parents. 

Green Scene.  Violet blue (VTBL) and spectrum blue (RHS 105B/C or true blue – BL) are two separate anthocyanin pigments controlled by separate dominant genes.  Both appear as separate streaks in the style crests of some cultivars. Inbreeding can isolate most of the spectrum blue from the violet blue as in our ‘America the Beautiful’ from selfing ‘Daredevil’ or completely isolate only spectrum blue as in our SDBs ‘Karen Jones’ and ‘Mir’.  John Weiler isolated the spectrum blue in his light turquoise ‘Navajo Jewel’ that I crossed on lavender blue ‘Clear Day’ producing my turquoise and sky blue blend, ‘Sky and Sun’. A cultivar with only spectrum blue times a spectrum yellow can produce a true green, turquoise, or teal color.  My SDB ‘Teagan’ (‘Winter Embrace’ X ‘Karen Jones’) has unique, true turquoise (RHS 115C/D) falls with yellow green (151C) hafts.  Crossing a cultivar with violet blue to lighter lavender-blue times a yellow cultivar may produce greyedgreen or olive offspring, but not a pure, spectral green color.

Color Me Beautiful.  Some judges feel that muted, greyed colors are “muddy”.  Any catalog for expensive clothes will show these colors are considered choice.  I say greyed shades and pastel tints of the basic hues are equally as attractive as “rich”, intense spectral hues.  I consider such views as prejudices based on one’s own eye for what is beautiful.  The real question is “As a whole, is the cultivar clump with its stalks and flowers a thing of beauty”.  For ‘Thornbird’ this is a resounding, “Yes”.

RHS 4 All.  All hybridizers should be strongly encouraged to describe their registered cultivars using the RHS (Royal Horticultural Society) color charts that are used by most plant societies.  The RHS charts are expensive; however, older sets are still usable and AIS affiliate clubs could purchase a new or used set for their hybridizers. They are free, on line with the Azalea Society, but you can not make a print copy.   

Minds in Line.  It would be helpful if all hybridizers used an alphanumeric naming system for their seedlings giving the year and cross number with seedling designating letters; especially for recessive traits, like orange beards and fall rebloom, that can vary greatly among siblings.  (Example: #2011-75 B.OR/FRE.)  The AIS printed registrations are communications to other hybridizers and could be in a more uniform language.  We use abbreviations E, M, and L for early, middle, and late bloom times within each class, and VE (very early) and VL (very late).  We use S. F. and B. for standards, falls, and beards.  I suggest we use ST to abbreviate style arms.  I prefer using VB for variegated blossoms.  The color is not “broken” but pied, batik, or brindled. “Variegated” has priority and BC means bicolor. VF is already used for variegated foliage.  Other abbreviations are: PBF-purple base foliage, SF-self, CSF-complete self, BC-bicolor, BT-bitone, NG-neglecta, AM-amoena, RAM- reverse amoena, VG-variegata as yellow S. and maroon or ruby red F., PL-plicata, LU-luminata, FC-fanciata, GL-glaciata, UM-umbrata, EC-Emma Cook, SA-space age, BD-blend, SB-sunburst (sunspray), and ZN-zonal.  A color has three properties: 1. HUE, its color in the visual light spectrum (ROYGBIV- red, orange, yellow, green, blue, indigo, and violet), 2.  INTENSITY, and 3. ADULTERATION with either white to give pastel TINTS or mixed with grey, black, or its complementary color as blue with orange, red with green, or yellow with violet to give SHADES.   Abbreviations for basic colors are: WT-white, BK-black, GY-greyed, PT-pastel or whitened, LT-light, DK-dark, R-red, OR-orange, Y-yellow, G-green, BG-blue green, BL-blue, PR-purple, VT-violet, LV-lavender, PK-pink, PC-peach, MU-mauve, BN-brown, MN-maroon, TN-tan, TQ-turquoise, TL-teal, and OL-olive.  You can hyphenate some of these like VT-BL for violet-blue, R-OR for red-orange, Y-OR for yellow-orange, Y-G for yellow-green, R-BK for red-black, etc.  These abbreviations are useful to record the traits of seedlings.

Boldly Go.  Garden judges can embrace the novel and diverse and resist the temptation to stifle hybridizers with rules based on personal preferences and fixed mind-sets.  They can encourage young and new hybridizers to introduce their creations with selected traits, such as vigorous growth with good increase, as well as durability that is resistance to cold, heat, drought, disease organisms, iris-eating pests, and weed competition.  Valuable goals include: extended and more reliable rebloom and in the colder zones 4 and 5, new SA flower forms, new color patterns, new variegated flowers and foliage, long-lived garden clumps that are floriferous bearing many stalks with long lasting flowers, and color breaks for spectrum red and blue, grass green, and blue greens like sea green, turquoise, and teal. Bearded iris hybridizing has awesome, unlimited horizons for youths of all ages.  “To infinity and beyond!” The beauty of irises brings us together to enjoy rewarding, lifelong friendships.



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