Genetic Susceptibility to Rot
David Silverberg wrote:
: Someone asked what makes certain iris rot when no others will. If we
: investigate the hybridizer and his practices you will find that in many
: instances that there is a lot of line breeding ( iris incest if you will
: !!!). Continued practice will alway magnify the weak spots in the genetic
: character, as with the classic biological case studies of the Jukes and the
: Kallikaks (sp?). I may be right or I may be wrong. COMMENTS?????
"Never say 'always' or 'never' ! " -- Herb McKusick
I certainly agree that too much line-breeding can lead to problems, just as too
much out-crossing can make it difficult to recover desirable traits. The
"secret" to success is maintaining an appropriate balance.
In this case, I think it depends a great deal on whether the hybridizer has been
consciously selecting for rot resistance. After doing so for many years, I've
found I have better results from crossing clones that are "cousins" (sometimes
rather distant ones) than from crossing to either sibs or half-sibs or from
crossing "unrelated" ones.
Next question for the opinion poll: how distant must the relationship be, for a
cross to be considered an "outcross"?
Sharon McAllister (firstname.lastname@example.org)
Coping with monsoon season in southern New Mexico