Occurrence of Mycotoxins and Toxigenic Fungi in Groundnut (Arachis hypogaea L.) Seeds in Andhra Pradesh, India

Abstract

Andhra Pradesh is one of the major groundnut growing states in India. A total of 182 groundnut samples collected at harvesting from farmers fields in five districts, namely; Anantapur, Chittoor, Cuddapah, Kurnool, and Mahaboobnagar, during 1999 and 2000 rainy seasons were evaluated for the presence of mycotoxins (both aflatoxins and zearalenone) and toxigenic fungi. In samples collected from each district, average seed infection by Aspergillus flavus and Fusarium spp. was 11.9-18.3% and 5.6-12.8% in 1999, and 9.5-14.1% and 9.4-11.9% in 2000, respectively. Among the samples collected, 20.3% and 16.5% were contaminated with aflatoxin in 1999 and 2000, respectively, and in 11.4% and 8.7% of the seed samples collected in two seasons, the aflatoxin content was >30 <TEX>$\mu\textrm{g}$</TEX>/kg. An alarming aflatoxin content of 851.9<TEX>$\mu\textrm{g}$</TEX>/kg was found in samples collected from Anantapur district during the rainy season in 1999. Zearalenone was not detected in any of the samples collected in 1999, while 2 out of 103 samples collected in 2000 were contaminated with 35.1 and 129.4<TEX>$\mu\textrm{g}$</TEX>/kg. Under in vitro cultural conditions, 35.8% of the 173 A. flavus isolates collected from the groundnut samples produced aflatoxins at concentrations of 94.3-1598.6 ng/<TEX>$\textrm{m}{\ell}$</TEX> and 3% of the 266 Fusarium spp. isolates produced 98.1-847.3 <TEX>$\mu\textrm{g}$</TEX>/g of zearalenone. The results emphasize the need for a more systematic and regular monitoring of pre-harvest aflatoxin contamination.