Abstract:

Bacterial wilt disease is a serious threat to peanut production in China. Understanding the genetic diversity in peanut genotypes with bacterial wilt resistance and enhancing the germplasm resources are helpful for peanut breeding for disease resistance. In this study, the DNA polymorphism among 31 genotypes with various bacterial wilt resistance including 4 botanical types from 2 subspecies of cultivated peanut were assessed by SSR and AFLP analysis. Polymorphism in morphological characters and seed chemical composition were also analyzed. The results indicated that there was enough polymorphism in the peanut genotypes with bacterial wilt resistance based on SSR and AFLP analysis. The SSR-based genetic distance was bigger than the AFLP-based genetic distance among the 31 genotypes. But the cluster based on SSR data was very similar to that based on AFLP data. Considering the botanical type, origin and pedigree of the genotypes used in the study, the cluster based on SSR data was conformed with that based on morphological and seed quality characters. However, there were a few differences between the cluster through AFLP approach and that through morphological and seed quality characters. The distances between the high yielding varieties with bacterial wilt susceptivity “Zhonghua 5” and the genotypes of Var. Virginia and Hirsuta were big relatively. But the distances between “Zhonghua 5” and “Yuanza 9102” as well as the two donors used widely “Xiekangqing” and “Tanshan Sanlirou” were small.

Key words: Peanut, Germplasm with bacterial wilt resistance, DNA polymorphism, SSR, AFLP, morphological polymorphism