Monday, November 11, 2019

Did We Give Up on the Recessive Amoenas too Early?

By Kevin Vaughn
Amoenas and variegatas have long been favorites of iris growers.  The early amoenas and variegatas were all derived from I. variegata and had many problems associated with that species, chiefly very veined hafts, and a pattern of striped falls rather than solid ones.  Breeders were persistent in their work, despite poor germination of crosses involving amoenas. Cultivars like the Dykes Medal winner dark purple amoena ‘Wabash’ and variegatas like ‘Mexico’ and ‘Pretender’ were very popular irises in their day and had covered up most of the problems in this breeding line.  In fact, ‘Wabash’ topped the AIS popularity poll for many years. Crosses of these recessive amoenas to yellow amoenas resulted in the unusual green amoena ‘Frosted Mint’ (one of my childhood favorites) and red amoena ‘Repartee’. (Editor's note: Kevin sent images of seedlings as examples and I do not have numbers for any of these photos, but they give an idea of what he is getting out of these lines.)

A revolution happened in the 50’s when Paul Cook found that I. reichenbachii had a dominant inhibitor of the TB anthocyanins in the standards only, resulting in amoenas, neglectas, and bicolor patterns only dreamed about in the past.  Paul’s ‘Whole Cloth’ won the Dykes Medal and most deservedly so as it was not only a beautiful iris but an important breeders’ iris as well. Almost all breeders made a few crosses with ‘Whole Cloth’ and generally with good results.  Moreover, these dominant amoenas had seed that germinated well and the flowers had none of the veined hafts so typical of the recessive amoenas of the past. People flocked to these amoenas, basically dropping the old recessive amoenas, although Jesse Wills, Catherine and Kenneth Smith and a few other brave souls kept the recessive amoenas going for a while. Catherine Smith’s ‘Bread and Wine’ may be the last of these, in the 1970’s.

In the MTBs, recessive amoenas and variegatas are alive and well!  In fact, if you breed MTBs you can’t help but getting them in spades.  As I looked through my patch of MTB seedlings this past spring, I saw many colors and patterns that I have not seen much or at all in the TBs.  The variety of variegatas is quite staggering, including those with patterning of colors on the falls, stitching on the standards, and several just in STRIPES.  In the opposite direction, my ‘Booyah’ and many of its seedlings had nearly solid falls with minimal haft marks. Amoenas followed the same patterns, with some striped variations in delicate stripes and some all-over versions as well as nearly solid colored falls.  When Rick Tasco, Roger Duncan and Keith Keppel stopped by one day, they were equally impressed in the variety of colors and patterns that were occurring in these recessive amoenas and variegatas.

When these recessive amoenas and variegatas are crossed into the plicatas and then recombined the variety of plicata patterns also increased with lots of strong bitoned and bicolor plicatas plus unusual distributions of the dots and spots.  I inherited a number of Jean Witt’s seedlings and she had explored these variegata-influenced plicatas a good bit. Crosses with them give even further variations. Some of these plicatas have the looks of things that Rick Ernst got out of his ‘Ring Around Rosie’ lines.  These tetraploid lines may have some variegata influence too.

Catherine Smith sent me a plant of ‘Repartee’ when I was a kid. I was impressed with how red the falls of that iris are and especially so when it bloomed in my garden in 1968!  Amazingly it still looks very red to me. ‘Repartee’ is a cross of the purple neglecta ‘Grosvenor’ with a yellow amoena and that overlay of strong purple with an inner yellow layer gives a very red effect.  Admittedly, ‘Repartee’ has some problems. The stalk is awful with buds toed in and the form of the flower is a bit “blobby”, although I have seen worse.
Fortunately yellow amoenas have improved a LOT since 1968 and I crossed several of them onto ‘Repartee’.  The F1 crosses of ‘Repartee’ X yellow amoenas gave almost all red amoenas/ pale variegatas. The stalks on these were much better than ‘Repartee’ and the forms began to approach the yellow amoenas.  Rather than sibbing these seedlings, I crossed them once again to yellow amoenas, hoping to obtain even better form. Those seedlings bloomed in 2018 and the improvements were noticeable. Much better forms and quite red falls were the norm.  Interestingly, several of these seedlings didn’t have solid falls but rather a splashed phenotype. Yellow amoenas have the dominant inhibitor I that suppresses anthocyanin production but the anthocyanins in amoenas are not fully inhibited by this gene.  It is possible that these anthocyanin-free sectors are due to some partial inhibition by I.  None of these is quite a finished product but they are interesting and with quite good color and very vigorous plants.  I’ll see ~50of the best of these red amoenas sib crossed (best form X best color) in the spring. I don’t expect any introductions from this line in the near future, but it’s been fun to see what the recessive amoenas can do.

This makes me wonder out loud whether we were wise in giving up on recessive amoenas too early despite their many problems.  Hopefully there will be a few more brave souls out there to use them in crosses.

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