Bacterial Leaf Blight in Rice: Exploring Pathogen Life Cycle, Resistance Genes, and MAS Breeding Strategies

Rice (Oryza sativa L.) is one of the most important food crops grown in various agro-climatic conditions and is the staple food for more than half of the world’s population. More than 3.5 billion people depend on rice for more than 20 % of their daily calorie requirement (Maclean et al., 2013). Globally it is grown over 165.25 m ha with the production of 509.87 million tonnes milled rice (FAOSTAT, 2021). However, the production of rice is being adversely affected by various biotic and abiotic stresses. Bacterial leaf blight (BLB), caused by Xanthomonas oryzae pv. oryzae (Xoo), is a major disease affecting rice production worldwide, leading to significant yield losses. It is a serious problem in South-West monsoon season (Kharif season). It is a vascular disease and the symptoms can be visualized in terms of drying and yellowing of leaves which starts from the leaf tips and proceed downward. Understanding the pathogen’s life cycle and its interaction with rice plants is crucial for developing effective management strategies. This review provides a comprehensive overview of the biology and epidemiology of Xoo, highlighting its infection mechanisms and life cycle. We explore the genetic basis of BLB resistance in rice, focusing on the identification and characterization of Resistance genes (R genes) that confer immunity against various Xoo strains. The integration of these R genes through conventional breeding and advanced molecular techniques such as Marker-Assisted Selection (MAS) has led to the development of resistant rice varieties.