EFFECT OF INSECT-FUNGUS INTERACTIONS ON AFLATOXIN PRODUCTION IN STORED HORSEGRAM
EFFECT OF INSECT-FUNGUS INTERACTIONS ON AFLATOXIN PRODUCTION IN STORED DOLICHOS BIFLORUS
Department of Botany, Nizani College, Osniania University, Hyderabad - 500 001, India.
Background and objectives
Extensive information is available on incidence and levels of various mycotoxins in cereals and oil seeds. Data on mycotoxin contamination in pulses is meagre (1) & (2), though they are second to cereals as human food in India. Studies on one of the protein rich pulses, Dolichos biflorus were carried out to know how far low risk pulses are free from aflatoxin contamination under severe insect infestation in storage.
Results and conclusions
No aflatoxin was reported in field and freshly harvested seeds despite the occurrence of Aspergillus flavus. After 6 months of storage, however, the samples were positive to one or the other aflatoxins with the concentration range of 10-350 ug/kg. Forty-five percent were insect damaged and less than 12% normal seed samples were aflatoxin positive. The highest amount of aflatoxin Bl occurred in insect damaged seed samples. Stored seeds were prone to insect infestation and samples turned to greyish white powder under severe insect pest damage. Insect infestation during storage promoted external seed-borne fungi (including toxigenic ones) to enter the seeds through the cracks and pores made by the insects subsequently leading to aflatoxin formation. A positive correlation between the length of the storage time and levels of aflatoxin was observed.
1. Sinha, R K, 1980. Biological Bulletin of India 2, 76-77.
2. Reddy, B N, Nusrath, M. 1983. Current Science 52,1024.