Enhancing Resistance to Aflatoxin in Groundnut Through Seed Coat-Mediated Lignification

Abstract

Groundnut (Arachis hypogaea L.) is an important oilseed crop of the world. Aflatoxin contamination of seeds by Aspergillus flavus is limiting groundnut quality and trade in India. Thirty-six groundnut genotypes were evaluated for A. flavus incidence and aflatoxin accumulation using in-vitro seed colonization assay and under field conditions. The study identified one high oleic acid line ICGV 15090 with low A. flavus severity (1.0) and aflatoxin accumulation (1358.63 ppb) and infection percentage of 9.33 with aflatoxin contamination of 2.59 ppb under both the conditions. The genotype ICGV 15090 also recorded high cellulose (120 mg/g cell wall), anthocynanin (0.22) and lignin (3.55%) contents in the seed coat. The negative correlation between aflatoxin and lignin content (r = -0.67) indicated the role of seed coat cell wall lignin in conferring resistance to aflatoxin contamination in groundnut. Breeding for lignin fortification in seed coat can be explored to inhibit A. flavus infection and aflatoxin contamination in groundnut.