Genetic variation vis-à-vis molecular polymorphism in groundnut, Arachis hypogaea L.

Recent studies on the genus Arachis using molecular markers have revealed very little demonstrable polymorphism in the cultivated groundnut, A. hypogaea. This has led to the hasty generalization that the groundnut lacks genetic variation. However, this is in complete contradiction to the results of other lines of investigations into the origin and evolution of A. hypogaea. Further, a characterization of the world collection for various traits also shows significant levels of variation for almost all genetic traits. The literature review in this article suggests that the lack of genetic variation was inferred because of an inadequacy in the material studied, and the range of techniques used to study molecular polymorphism. A comprehensive and rigorous examination of the material available in the groundnut world collection, either by improving current techniques, or by using such advanced techniques as SSRs and AFLP could well reveal polymorphism at the molecular level.