Comprehensive Genomic and Molecular Breeding Efforts to Understand Genetic Control of Aflatoxin Contamination in Peanut

Peanut production, quality and trade is predominantly affected by aflatoxin contamination especially under rainfed conditions making produce unfit for human and animal consumption because of its carcinogenic effect. Hence, finding the resistance source is the need of the hour for aflatoxin resistance breeding. Attempts are therefore being made to use different genomic approaches to tackle this challenge. In the first approach, RNA-sequencing of resistant (J 11, ICGV 91278) and susceptible (JL 24) genotypes has been carried out to study the resistance to in-vitro and pre-harvest colonization of seeds by Aspergillus flavus (strain AF-11-4). The preliminary results in the in-vitro seed colonization showed several differentially expressed genes in control and infected samples of resistant and susceptible genotypes, which provide the insights of the probable resistance mechanisms. In the second approach, peanut ‘reference set’ was screened for aflatoxin contamination across four environments at Niger and the analysis is underway to identify marker-trait associations for aflatoxin contamination. As there are no bi-parental populations reported for aflatoxin resistance in peanut, multi-parent advanced generation intercross (MAGIC) populations are being developed for aflatoxin resistance along with other important agronomic traits as the third approach. In summary, combined approaches will provide entities responsible for aflatoxin contamination and their use in aflatoxin-free peanut improvement.