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Date: | Mon, 5 Feb 2007 20:37:57 -0500 |
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Another great post Peter! I love this history and I am glad you see value
in dusting this work off for another look. The remarkable thing about the
program that Frank Pellet and Dadant got off the ground in 1935 was how
quickly their population responded to selection. The history of this
program is covered briefly in the newest edition of Laidlaw and Page. It
is reviewed in much more detail by:
Rothenbuhler, W. C. 1958. Genetics and breeding of the honey bee. Annu.
Rev. Entomol. 3: 161-180.
Spivak, M. and M. Gilliam. 1998. Hygienic behavior of honey bees and its
application for control of brood diseases and varroa; Part I. Hygienic
behavior and resistance to American foulbrood. Bee World. 79(3): 124-134.
I have often wondered how to square the moderate-low heritability of
hygienic behaviour with the rapid increase in AFB-resistance in the
breeding program Pellet started. One obvious difference is that Pellet's
assay was a to put a 2 x 2.5 inch insert of AFB-infected comb into each
prospective breeder. With a different assay it was likely that their
selection "net" may have "dragged" in a number of other more heritable AFB-
resistant traits... thus the rapid gain. This is of interest to me
because it suggests that their may be considerable fruits to be picked by
taking a second look at other AFB-resistance traits. I know of one
excellent attempt, which was tragically cut short, to look at AFB-
resistance in larvae. The preliminary work demonstrated considerable
differences between two commercial bee stocks in Denmark (the heritability
of this difference remains unknown).
http://www.planteinfo.dk/bier/tolerance.pdf
It is indeed interesting how breeding for disease-resistance has again
entered onto the stage. The ABJs in the 1940s are a veritable battle of
opinions for and against breeding vs. sulfa. Sulfa won the day. The last
report from the aforementioned breeding program is in 1949, when it seems
to have disolved into a hybrid breeding program... anyone know the rest of
this story? Steve Taber was an avocate of breeding for hygienic behaviour,
and then Dr. Spivak renewed this work in the 1990s with some absolutely
top-rate research. The revival is in full swing.
The lack of interest to date may have to do with the low priority AFB-
resistance has among beekeepers. Denis van Englesdorp was the first to
demonstrate to me how little interest there was. In 2000 he surveyed
Ontario beekeepers. He gave them 100 points to allocate among a number of
important traits. While they allocated 35 points to honey production and
10 points to varroa resistance, AFB resistance garnered a measley 7 points
(behind overwintering ability, reisistance to tracheal mites, and more-or-
less tied with spring build up). I suspect AFB-resistance has moved up in
importance, but nonetheless it has a way to climb in the eyes of the
beekeeping industry before queen breeders give it attention, particularily
given its moderate-low heritability of HB.
van Engelsdorp, D. and G. W. Otis. 2000. Application of a modified
selection index for honey bees (Hymenoptera: Apidae). J. Econ. Entomol.
93(6): 1606-1612.
I do not, however, believe that economics should be the only thing
deciding whether a trait is bred for. There is an arguement that the
decision to give up line breeding in corn in favour of hybrids was not a
biologically-based decision, but rather one based on the fact that
investment was more readily raised for the latter because the F2 are not-
viable.
http://www.findarticles.com/p/articles/mi_m1132/is_v38/ai_4325182/pg_1
Thanks again Peter for brining this topic up.
Adony
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