A short vignette about Barbara McClintock:
Before the Genes Jumped, 1930s
Youngsters here would benefit from learning more about her struggles with the scientific establisment in proving the existence of transposons in maize. Roses have a lot of ‘unusual’ genetics that are likely due to transposable elements.
Don, I have just read that article. it is above my head, but. great reading. I call it thought provoking. As you will know I am very newto this forum and seed raising. If this next part is not appropriate please delete it. Who amongst rose people are at this stage researching or researched the same principle, does that make sense, I have not explained myself very well.
Interesting article- there is at least one good book on the life of Barbara McClintock. She had what she called “A Feeling for the Organism”. Her work was pioneering, and when written up so complex that few people could grasp it. When I was in college, we had a genetics course taught by someone who worked out of the mainstream and her work was right at the top of the curiosities we considered. But until people knew about DNA replication and viruses integrating themselves into the genomes of organisms, her work was really hard to comprehend and appreciate. But I think sometimes the case is over-stated. Good geneticists certainly knew of her work, and a few understood it. That’s why she got the Nobel prize eventually. She gave a talk to our department when I was in graduate school in NYC, complete with beautifully striped ears of maize.
No one is really working on transposons in roses because you need a good genetic system to do that, and roses have a too long generation time for most geneticists, plus some self-infertility. That makes it really hard to get uniform lines like are available in maize or drosophila. There are traits in roses that probably are caused by transposons jumping. Stripes and spots would be the most obvious.
Another level of complexity that only came to light after McClintock’s death is the role of RNA in controlling what are called epigenetic traits. those may in part account for some of the reported maternal effects. Old-time breeders were of teh opinion that the male and female contributed different traits to roses, and that may be correct, though we are just about clueless as to what traits are controlled that way. And it may be different in different species. For sure all the caninae have a diffferent way of managing things, because of their peculiar breeding system.
I’ve written a few articles over the years about some of these things, in the RHA newsletter. So has David Z.
About nine years ago I was given a rose called Wendy (Schuurman NZ). It was pollinated with Abraham Darby and out of one hip, came 17 different variations of colour and bloom structure, as shown in the photograph below.
[attachment 275 068182b.jpg]
In the same year Wendy was pollinated with Altissimo giving these results.
[attachment 276 06881.jpg]
One of the reasons I used Wendy was, its parent White Dream was known to throw alot of sports and I thought with this instability happening good things could be bred out of it. Wendy its self has not sported for me but numerous numbers of its offspring have. It is unusual that it does not set hips by itself , but when fertilized at the right time will stick without any problems. Its seed viability is very good with most seed produced germinating very quickly. Stratification is around 5wks maximum, with germination occurring within that period. Most have germinated post stratification by 2wks.
F1 crosses of Wendy also display this ability to produce large numbers of variation in their offspring, as to F2 offspring, still working on it.
boy that bought some interest in the post??
Warren,
It was very interesting for me to see composite seedling pics like that. Your post inspired me to look up the three roses mentioned on HMF.
Do you have a pic of Wendy herself? I didn’t see anything that I thought would be her amongst the "Wendy"s on HMF. I think I see some painted petals on the Altissimo cross…which parent do they come from?
Being from a cold climate, I’ve never used Abraham or Altissimo. In fact, I just ordered my first Austin rose.
Dam, the time ran out and just erased my post.
Warren, I thought it was very interesting.
Also a new book came out that Michael Crichton almost completed dealing with the micro world. Plants are far outnumbered by insects and microbes and would not exist if they did not develop their own defenses. This made me think that along with breeding for decease resistance that we should let the plants develop their own defenses. People have already noticed a difference in cuttings vs. original plant but has anyone taken cuttings of cuttings and ran that out about ten times to see if the plant has improved? This is not as good as the original post but will have to do. Neil
I was trying to show if Wendy displayed those transposons traites. Not only are there variation within siblings bloom structure and colour but also in foliage(coarse to fine), height, plant structure and prickle (size , numbers and shape.) Louis Lens, who bred White Dream, used some interesting material in his breeding, Dame Elegant this spring, produced a flowering cane with 104 blooms, and one of the Wendy X Abraham Darby rejects did similar but with 180+ blooms/ cane. This was rejected because bloom structure was not that good.
Wendy F1 crosses have a continual repeat and when these F1’s are crossed with Modern Ht’s or floribunda’s , there is a kind of hybrid vigour about them. These offspring display growth vigour out growing both parents and bloom size reacts the same way.
Thanks for the link, Don, it was very good reading!
Those photos are wonderful, Warren! It really shows how different the offspring were form each other. I had hips from What a Peach that showed a large variety of different shapes and colors too and never thought of displaying them in such a manner.
I would agree with you there Seil, Don very good link, wild horses could not have dragged me away untill i had finished it