Biotechnological Strategies for Development of Aflatoxin-Free Crops

Abstract

Aflatoxins are secondary metabolites produced by the fungal genus Aspergillus (mainly A. flavus and A. parasiticus) that contaminate various agricultural commodities, but most prevalent in maize, groundnut, and cotton. Considered to be potent carcinogens and teratogens to humans and farm animals, aflatoxin contamination gets accentuated by hot and dry weather conditions, insect feeding and mechanical damage during and after harvest, and improper storage conditions. Growing global concerns about aflatoxin contamination have prompted search for effective control measures and specific regulations to limit exposure to these mycotoxins. Cultural practices include use of resistant varieties; control of insect pests, timely harvesting, proper drying, storage, sorting, and cleaning of harvested produce curtail aflatoxin contamination to some extent, and biological control strategies such as use of atoxigenic A. flavus strains have proven efficient in preventing infection by aflatoxin-producing strains. Genetic engineering for aflatoxin resistance through gene overexpression and recent development in area of transgenics through host-induced gene silencing of aflatoxin biosynthesis pathway genes have provided promising results in several crops such as cotton, corn, and groundnut. This book’s chapter provides comprehensive overview on the various strategies and also updates the status of research to achieve aflatoxin resistance in crop plants. The role of various factors affecting aflatoxin contamination is also discussed that help to take appropriate measures for successful control of aflatoxin resistance. The availability of advanced molecular techniques, cutting edge tools and technologies provides greater potential to the development of markers and QTLs for aflatoxin resistance speeding up the development of durable aflatoxin-resistant varieties.