DNA Markers for Resistance to Post-Harvest Aflatoxin Accumulation in Arachis hypogaea L.
Aflatoxin contamination causes economic loss for the global peanut (Arachis hypogaea L.) industry and raises human and animal health concerns. Peanut genotypes with resistance to aflatoxin accumulation should be an important part of an integrated aflatoxin management program. This study was conducted to identify AFLP markers tightly linked to genetic factors controlling reduced aflatoxin accumulation. A segregating F2 population was generated by crossing high-aflatoxin producing cultivar Gregory with low-aflatoxin producing interspecific tetraploid line GP-NC WS 2, phenotyped for aflatoxin accumulation using an in vitro assay, and screened with AFLP markers previously identified to be associated with reduced aflatoxin accumulation. An F-test was used to determine whether markers were associated with the trait, a genetic linkage map was generated, and interval mapping was used to identify regions of the genome that influence aflatoxin accumulation. Gregory produced significantly more aflatoxin than GP-NC WS 2, and the F2 population exhibited high-parent heterosis. Thirty-five of 38 AFLP markers used to screen the F2 population had segregation distortion favoring the A. hypogaea cultivar. Six markers were significantly associated with reduced aflatoxin accumulation at the 5% significance level. Thirty-three markers were included in a genetic linkage map covering 60 cM and a putative QTL was identified at map position 9 cM. Linked markers could be utilized in a marker-assisted selection program to identify individuals that support low levels of aflatoxin accumulation.
Advisor:Thomas G. Isleib; Susana R. Milla-Lewis; Gary A. Payne; David A. Dickey
School:North Carolina State University
School Location:USA - North Carolina
Source Type:Master's Thesis
Date of Publication:04/23/2009