Breeding Louisiana Irises by George Arceneaux*
No iris devotee can hope to realize the full pleasure of his delightful avocation until he has made crosses and produced seedlings of his own. There is something closely akin to parental pride in the thrill experienced when a seedling of one’s own production “makes good”; yet strangely enough, for every serious hybridizer there are […]
Diploids from Tetraploids by Sam Norris*
One of my crosses, Professor Sigmund X chimera, as well as Joe Mertzweiller’s TD 87-34, show that diploid plants can result when the parent plant is a tetraploid. The book Haploids in Higher Plants answers some of the questions as to how this could happen. This can happen during the process of fertilization or in […]
Pondering Cultivar Names by Patrick O’Connor*
For a good while it has been past time to pick some names for new irises. I have quite a few seedlings that have paid their dues and have been waiting patiently. I am not sure why I procrastinate in reserving names and registering irises. Perhaps it is out of a fear that an iris […]
Hybridizing Variegated Tetraploid Louisiana Irises by William R. Bruner*
In 2000 as I prepared to row out my tetraploid Louisiana iris seedlings noticed that one of the tetraploid seedlings looked unhealthy or slightly chlorotic. Closer inspection showed that most of the larger leaves had streaks of yellow and cream. This tet seedling was planted along with its siblings in hopes that whatever was ailing […]
Tetraploid Louisiana Iris Hybridizing — Helpful Hints by William R. Bruner*
Over the past several years the late Samuel Norris of Kentucky and I have tried every trick in the book to get a higher number of tetraploid Louisiana iris seedlings. The two main obstacles seem to be poor seed set during bloom season and low germination of the few seed that are produced. With a little detective work and a […]
Efforts to Breed a True Red Louisiana Iris by Kevin Vaughn*
One of my first experiences with Louisiana irises was when I was a teenager in Massachusetts, growing a rather large collection of them on the protected west side of my parents house and heavily mulched for the winter with leaves and pine boughs. Two of the most impressive ones in that group were two brilliant […]
Variagated Louisiana Iris by Terry Aitken
Terry Aitken reports on a variagated Louisiana iris in his nursery in Vancouver, Washington and speculates what may have caused this to occur. We have been growing Louisianas in the Northwest for about 10 or 15 years. We have found that they pose a cultural challenge. Louisianas dearly love heat. The problem in the Northwest […]
Tetraploid Hybridizing – Problems Encountered
Before considering specific problems, we must answer the questions, What are tetraploids, and why the interest in them? The term “ploidy” or “ploidy level” refers to the number of sets of chromosomes in every cell of an organism, be it plant or animal. Every plant cell has a specific number of sets, with two sets representing diploids, three sets triploid, four sets […]
Colchicine-induced Polyploidy by Samuel N. Norris
ABSTRACT: The tetraploid breeding program of Mr. Norris includes both clonal and seedling treatment with colchicine, an alkaloid found in the autumn crocus, Colchicum autumnale. Clonal treatment involves injecting O.5cc of a 0.4% colchicine solution into the plant fan just above the growing point, concentrating on offsets which would be expected to bloom the following year. Chimeras normally are produced […]
Using Herbicide Treatments to Induce Tetraploidy in LA Irises
by Kevin C. Vaughn*, PhD Louisiana Irises and Comments on Existing Cultivars ABSTRACT: The herbicides trifluralin (TREFlAN) and oryzalin (SURFLAN) were selected as chemical compounds likely to increase ploidy levels in Louisiana irises. The compounds, while not as .toxic to animals, affect the development of plant tubulin protein in the same way as colchicine. Two batches of seedlings […]
