Durable Resistance of Rice to Major and Emerging Diseases: Current Status

Rice (Oryza sativa) is one of the most dominating cereal crop and half of the world has chosen it as staple food. Rice production has increased significantly but the productivity is not increased significantly to combat the global need. One of the major constraints of low productivity is biotic stresses faced by rice growers. Some of the important biotic stresses of rice are major diseases like brown spot, bacterial blight, blast, sheath blight and, few emerging but significant diseases like false smut, bakanae and sheath rot play crucial role in reducing yield per unit area and quality of rice. Host plant resistance is the most effective, economic and eco-friendly approach of mitigating disease like biotic stress problem.

The objective of this review is to compile data related to resistance in rice against various major and emerging diseases as well as their application to develop gene pyramided varieties that increase resistance to those pathogens to achieve durable resistance.

Diseases are one of the most important constraints for sustainable or demanding production level as well as maintaining different quality parameters of the rice. Different management practices including majority by chemical means, are not always the solution as they add production cost many times vis-à-vis causing pollution in every aspect. Thus, the development of durable resistant varieties is the best approach.

An array of robust molecular markers and genetic map of the crop has made the application of marker assisted selection possible for the traits controlled by resistant genes or quantitative trait loci (QTLs) to induce durable resistance in the crop.

A comprehensive assessment on identification, sources and deployment of resistance genes/QTLs of major and emerging diseases of rice will help in development of varieties of rice with durable resistant to major and emerging disease-causing pathogens.