Abstract:

Aflatoxin contamination is an important constraint to peanut industry worldwide. Genetic improvement for host resistance in peanut to fungal infection and aflatoxin production has been among the approaches for integrated management of the problem. However, the progress in peanut breeding for resistance to aflatoxin has been slow due to various reasons, among which, lack of cost-effective method for resistance identification in breeding materials or segregating progenies has been encountered in most breeding programs. Hence there is a need to develop a rapid and reliable screening method for selecting Aspergillus flavus infection resistance in peanut. Here we report two DNA markers closely linked with resistance to A. flavus infection using AFLP technique based on bulked segregant pools derived from F₂ progeny of Zhonghua 5×J11. J11 is resistant to seed infection by Aspergillus flavus and Zhonghua 5 is susceptible, two DNA markers linked with resistance to A. flavus infection were identified. The two specific fragments linked with seed infection resistance were, one about 440 bp which was named as marker E45/M53-440, and the other was about 520 bp, named as marker E44/M53-520, the former marker linkage distance to the resistant gene was 6.6 cM, while the latter was 8.8 cM. Twenty peanut genotypes with resistance to infection of A. flavus and seven susceptible genotypes were used to verify the reliability of the resistance markers, and high correlation between the molecular markers and the resistance result. The result shows that the potential of the markers which can be used in other resistant peanut genotypes to seed infection by A. flavus.

Key words: Peanut (Arachis hypogaea), Aspergillus flavus, AFLP merker, MAS