Hot on the heels of a recent nibble on breeding cowpeas for Striga resistance comes a paper in GRACE on the diversity being exploited by cowpea breeding programmes in the US and Africa. It turns out that these programmes are using non-overlapping sets of genetic material and that therefore
US and Asian breeding programs could increase genetic variability in their programs substantially by incorporating germplasm from West Africa, while national programs in West Africa should consider introgression of Asian germplasm and germplasm from other parts of Africa into their programs to ensure long-term gains from selection.
That’s what we mean when we talk about global interdependence in plant genetic resources, I guess. And that’s why the International Treaty was negotiated: to facilitate the exchanges of germplasm necessary to broaden plant breeding programmes worldwide.
Interesting… But, reading the study I am left wondering how well founded their conclusion is. It would actually be more conspicuous if the breeding lines from the US and West Africa showed the same pattern of genetic diversity.
Perhaps you’d like to expand on that in a follow-up post?
Well, you would expect and hope for them to display a different range of polymorphism because they have been selected and bred for widely different conditions, right? Breeding will always lead to narrowing of the genetic base of the breeding population as the breeder both wants to fix certain alleles and get rid of others. The neutral markers analyzed in this study seem to be a good indicator for this process. However, in the discussion part of the study one can read: “Despite substantial phenotypic variability observed in US germplasm for many morphological and developmental traits, US cowpea breeding programs appear to lack genetic diversity.†My feeling is that they get two things mixed up: 1) Conserving and maintaining the broadest possible range of the geenpool of cowpea is important. 2) Breeding relies on selection of suitable subsets of this genepool. The confounded mix would be: All cultivars should contain as much genetic diversity as possible.
Dear sir,
I am a student of agriculture in India.Kindly give me the details about the intraspecific cross between Vigna ungiculata (subspecies ungiculata and sesquepedalis).They are the important grain and vegetable types in southIndia.On crossing will they form an intermediate variety.
Yours faithfully
Rm.Nagalakshmi