Quote:
Originally Posted by marktutt
I've trialed a lot of the cold tolerant varieties mentioned trying to deal with the weather fluctuations we see here in the spring. (Bower, I know I've grown both Cold Set and Siletz; I'll check to see if I still have seeds if you like.)
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Mark, if you find the seeds I'd love to grow them, thanks. I would like to see how the parthenocarpy trait plays out and compare with others.
Here are the notes and urls to research on parthenocarpy from my reading files last winter, mostly gleanings from abstracts. I'm sure the full papers contain more info so if anyone has read them I hope will share it with us:
parthenocarpy and cold weather fruit set:
http://www.actahort.org/books/200/200_16.htm
controlled by a single recessive gene. high GA in flower ovaries
additive effects of three recessive genes:
http://www.springerlink.com/content/v67u238260nx4548/
QTL's:
http://www.ncbi.nlm.nih.gov/pubmed/18231773
http://www.ncbi.nlm.nih.gov/pubmed/19700496
http://www.ncbi.nlm.nih.gov/pubmed/19619340
GMO parthenocarpy: re seedless.
http://www.ncbi.nlm.nih.gov/pubmed/16371162
cultivars with parthenocarpy:
[PDF] Genetics of the parthenocarpy for tomato varieties 'Sub-Arctic Plenty','75/59'and 'Severianin'
cultivar Nadja: parthenocarpy due to a single recessive gene:
http://www.springerlink.com/content/j46459731p800218/
cultivar Severianin : two recessive genes
http://www.springerlink.com/content/v272m3443w220t17/
in line RP 75/59: three recessive genes
http://www.springerlink.com/content/v67u238260nx4548/
E. Vardy, Dvora Lapushner, A. Genizi and J. Hewitt
linkage of one gene to diageotropica (dgt) located on chromosome 1 L site 152, dgt: "Plant habit prostrate due to reduced gravitropic response; growth retarded; stems and leaves droopy; cotelydons concave. Roots grow horizontally rather than downwards."
and a second gene to yellow verescent (yv) located on chromosome 6 L site 34
Light yellow-green leaves, paler at growing point, which has velvety appearance.
yv 2 yellow virescent
vel^2, vel1^2 Smaller, irregular bush; short internodes; soft yellow, velvety growing points shading to normal green below; smaller than vel.
yv -- yellow virescent Pale yellow-green; virescent foliage. several male sterile alleles are also described.
here's a full text piece of work on Severianin:
http://www.plantphysiol.org/content/122/2/471.full
here's one on determining parthenocarpy in the F2:
http://www.sciencedirect.com/science...04423887900112
I haven't re-read any of these to check or clarify my notes, but it looks like there are adverse phenotypes associated with several of the genes for parthenocarpy. This seems to be typical of other cold tolerance traits as well, afaict, with a few exceptions. So it's not surprising that many of the available cold tolerant earliest varieties are described as "semideterminate" or smaller plants.
Maybe being smaller is part of the strategy to survive cold....