Association between aflatoxin contamination and N2 fixation in peanut under drought conditions

Document Type: Research Paper

Authors

1 Department of Agronomy, Faculty of Agriculture at Kamphaeng Saen, Kasetsart University, Nakhon Pathom 73140, Thailand.

2 Department of Plant Science and Agricultural Resources, Faculty of Agriculture, Khon Kaen University, Khon Kaen 40002, Thailand.

3 School of Crop Production Technology, Institute of Agricultural Technology, Suranaree University of Technology, Nakhon Ratchasima 30000, Thailand.

4 Crop Genetics and Breeding Research Unit, USDA/ARS, Coastal Plain Experiment Station, Tifton, Georgia 31793, USA.

Abstract

Traits related to nitrogen fixation may be used as indirect selection criteria for
aflatoxin resistance in peanut. The aim of this study was to investigate the
relationship between N2 fixation traits and aflatoxin contamination in peanut under
different drought conditions. Eleven peanut genotypes were evaluated under three
water regimes for two seasons in the field. Data were observed on kernel infection
by Aspergillus flavus, aflatoxin contamination, total nitrogen content, N2 fixation
and its related traits viz. nodule number, nodule dry weight and nitrogenese
activity. Drought stress reduced total nitrogen content and N2 fixation, but it
increased kernel infection and aflatoxin contamination. Total nitrogen content, N2
fixation and its related traits had negative and significant effects on kernel infection
and aflatoxin contamination especially under drought conditions. In addition,
negative correlations between kernel infection and aflatoxin contamination with
drought tolerance index (DTI) of N2 fixation traits were also found. The results
indicated that the ability to maintain high N2 fixation under drought conditions of
peanut genotypes can result in better resistance to aflatoxin contamination.

Keywords