Evaluation of Groundnut Genotypes for Resistance to Early Leaf Spot Disease and Preharvest Aflatoxin Contamination

Abstract

Aflatoxin caused by Aspergillus flavus is a major field to storage contaminant in groundnut seed production, whereas defoliation diseases  in groundnut caused by Passalora arachidicola and Nothopassalora personata are two of the most yield-limiting biotic stresses.  The present study was to identify groundnut genotypes with resistance to leaf spot disease and preharvest aflatoxin contamination.  Thirty-three groundnut genotypes originating from crosses between Schubert × 43-09-03-02 and TS32-1 × 60-02-03-02 including three  checks: Manipinta, Chinese and ICGV03401 were evaluated in screenhouse and field studies. In the screenhouse experiment, the groundnut genotypes were arranged in a Complete Randomized Design with three replications. The field experiment was laid in a 9 × 4  alpha lattice design with three replications. Results revealed that A. flavus population in the soil increased when the fields were  inoculated with the A. flavus isolate. Again, results show that these groundnut genotypes namely, L024, L030, L078B, L086A, L092 and  L096, showed resistance to leaf spot disease infection. Also, except for L020B, which respectively showed a B and B aflatoxin of 71.5 and  72.0 ppb under field conditions and 1 2 132.1 and 131.5 ppb in pots, the remaining genotypes did not accumulate any aflatoxin at the preharvest level. In conclusion, the study identified groundnut genotypes L024, L030, L078B, L086A, L092 and L096 to be resistant to early  leaf spot disease and preharvest aflatoxin contamination. These genotypes could be tested in the future for their yield and stability under  diverse environments and released as varieties.