FD my man! ... wish I could help out with pheno' hunting for you! Males generally tend to be narrow in build anyway, right? I guess you'd be looking for a real stick of a guy-
...
Another thing I've been curious about, when you fem, do you use that pollen on the same female, or more ideally-?- use another female with the desired traits? I'm wondering how much genetic shuffling there is even when pollen is made, not for sex of course, but other traits,... I'm thinking in terms of the meiosis process that has that chromosomal crossover event (dusting off the ol' biology memory here-LOL!) where the chromosomes swap portions before the ploidy reduction divisions begin,... I can see how full-on selfing will result in the highest % recurrence of the desired traits,...
ok, this post got long fast. sorry about that!
yep the back crossing method takes time and lots of plants. There is another way to visualize a breeding program though. Semi hybrids. If you have two populations that have already been subjected to extensive breeding (like white gem) than this way can save tons of time.
"The gain in constitutional vigour, derived from an occasional cross between individuals of the same variety, but belonging to distinct families, or between distinct varieties, has not been so largely or so frequently discussed, as have the evil effects of too close interbreeding." (Darwin, 1868).
vs a typical breeding program,
The back crossing method has a downside, inbreeding messes things up eventually. So you can work on selecting from each group independently and cross them each generation and get a still better result.
"it was discovered that maize hybrids between varieties of different endosperm types produced a higher performance than among varieties with the same endosperm type. This discovery, by F.D. Richey, suggested that crosses between geographically or genetically distant parents expressed higher performance and, hence, increased heterosis." -Brummer
"The maize yield advance can be attributed in part to successful harnessing of heterosis, or hybrid vigor. (The other part is due to decreasing the number of unfavorable alleles in breeding populations [Waiters et al., 1991]). Early maize breeders astutely observed that certain populations, when crossed together, produced progeny better than the average of the parental populations (midparent heterosis) or than the better parental population (high-parent [HP] heterosis) (Hallauer et al., 1988). Heterosis has been observed for most agronomically important quantitative traits, though yield is the most widely discussed."
-Brummer "Capturing Heterosis in Forage Crop Cultivar Development"
