Submitted to: American Peanut Research and Education Society Proceedings
Publication Type: Abstract Only
Publication Acceptance Date: 4/15/2004
Publication Date: 12/15/2004
Citation: Lei, Y., B. Liao, S, H. Jiang, C. Holbrook, and B. Guo. 2004. Molecular marker for resistance to seed infection by Aspergillus flavus in peanut. Proc. Amer. Peanut Res. and Educ. Soc. 36:79-80. Interpretive Summary: not required
Technical Abstract: Aflatoxin contamination is an important constraint to the peanut industry throughout the world. Genetic improvement for host resistance to fungal infection and aflatoxin production has been among the approaches for integrated management of the problem. However, progress in breeding for resistance has been slow. One of the main constraints has been the lack of a cost-effective method for identification of resistance in breeding materials or segregating progenies. Hence there is a need to develop a rapid and reliable screening method for selecting Aspergillus flavus infection resistance in peanut. Here we report a DNA marker closely linked with resistance to A. flavus infection using AFLP technique on bulked segregant pools derived from F2 progeny of Zhonghua No.5 × J11. The two parents and their 108 F2 were tested for their reaction to A. flavus infection by inoculation under laboratory conditions. The infection index ranged from 0.205 to 0.913. The resistant parent, J11, was confirmed as resistant with an infection index as 0.231, while the susceptible Zhonghua No.5 had an infection index as 0.894. The DNAs of the two parents were extracted and tested with AFLP protocol. From the 256 primers pairs (EcoRI/MseI ) tested, twenty-four pairs showed polymorphism between the two parental lines. Then, the DNAs of 12 F2 segregating lines extremely resistant and susceptible to seed infection in the resistance identification were pooled and analyzed by the previously identified polymorphism primers and four primers pairs generated special bands in the resistant group. The polymorphic loci were further analyzed in all the F2 single plants. Two polymorphic markers linkaged with seed infection resistance were identified, one was about 440bp and the other was about 520bp. Based on analysis using MAPMAKER/EXP3.0, the former marker linkage distance to the resistant gene is 3.5cM while the latter was 9.4cM.