Drought Tolerance and Seed Coat Biochemical Resistance to Aspergilus flavus Infestation and Aflatoxin Contamination in Peanut

Drought stress severity leads to Aflatoxin B1 (AFB1) contamination (AC) increases in peanuts. Identifying drought-tolerant (DT) genotypes with resistance to Aspergillus flavus (A. flavus) colonization and/or infection could contribute to developing peanuts varieties resistant to aflatoxin contamination in the semi-arid tropics. This study aims to identify DT genotypes with seed coat biochemical resistance to A. flavus infestation and aflatoxin contamination. Experiments were carried out at ICRISAT Sahelian Centre to assess peanuts genotypes under intermittent water-stress (WS) regime imposed at pod filling stage and well-watered (WW) conditions. Parameters including pods yield and its components, A. flavus colonization incidence, aflatoxin contamination and seed coat total polyphenol (SCTPP) were investigated. The findings revealed significant decrease of pods yield and its components, except the number of immature pods per plant (IMPN) and the aflatoxin contamination which increased up to 67% and 55% respectively. Genotypes ICG 2106, ICG 311, ICG 4684, ICG 4543, and ICG 1415 revealed drought tolerance and low aflatoxin content. Furthermore, these genotypes showed a significant relationship between the aflatoxin resistance and the seed coat total polyphenol under the two water treatments (r2 = 0.80; r2 = 0.82), suggesting that despite WS, their seed coats were maintained intact, resulting in minimized aflatoxin contamination under an intermittent water deficit.