Inheritance of resistance to kernel infection by Aspergillusflavus and aflatoxin accumulation in groundnut

Abstract

Aflatoxin contamination in groundnut is one of the major barriers in international groundnut trade. Aflatoxin may cause human cancer, hepatitis and liver cirrhosis. The objectives of the study were to determine: (i) the level of resistance to Aspergillusflavus and aflatoxin accumulation in selected groundnut genotypes. (ii) the gene action for resistance to kernel infection by Aspergillusflavus and aflatoxin accumulation and (iii) heritability for Aspergillusflavus and aflatoxin accumulation resistance. Eighteen groundnut genotypes were evaluated in the laboratory. Nine genotypes selected were crossed in North Carolina II mating design of four by five parents and theF2 seeds obtained were evaluated in the laboratory for percent-severity kernel infection (PSKI3 and PSKI7), percentage kernel disease incidence (PKDI3 and PKDI7) and aflatoxin accumulation. Significant variation for PSKI3, PSKI7 and PKDI3 were observed. Baker’s ratio for both PSKI3 (0.73) and PSKI7 (0.67) were high, whilelow Baker’s ratio of 0.49 for aflatoxin accumulation was observed. Narrow–sense heritability of 66%-74% and 35%-46% for PSKI7 with A.flavus and aflatoxin accumulation were respectively observed. High narrow-sense heritability and additive variance for A.flavus indicate that the alleles for resistance to A.flavus can be easily transmitted to the offspring through recombination.