Modernization in plant breeding approaches for improving biotic stress resistance in crop plants

Abstract

Biotic stresses are a potential threat to global food security. The origin of new pathogens and insect races due to climatic and genetic factors is a major challenge for plant breeders in breeding biotic stress resistant crops. Yield losses due to biotic stresses have resulted in 800 million people underfed in the world. Reduced yield due to biotic stresses and increasing food demand put international food security at risk as 70% more food will be required in 2050. This review describes and compares the conventional and molecular genetics methods being used for breeding biotic stress resistant crops. In the past, classical breeding approaches like introduction, hybridization, composite crossing, multiline, and backcross breeding were utilized for this purpose. However, these methods were slow, expensive, and hectic for developing resistance in crops. Furthermore, breakdown of resistance due to fast evolving pathogens could not be coped with using these time consuming methods. Therefore, molecular genetics approaches like mutation, marker assisted selection (MAS), genomics, recombinant DNA technology, targeted induced local lesions in genome (TILLING), and virus induced gene silencing (VIGS) were adapted by breeders to develop effective resistance in crop plants in a shorter time. TILLING, being a nontransgenic method, is expected to become the most powerful tool for this purpose.