Vol. 10, Issue 1 (2021)

Author(s):
B Laxmi Prasanna, K Alekya, G Rekha and K Suman

Abstract:
Rice (Oryza sativa L.) productivity is significantly constrained by biotic and abiotic stresses, with bacterial leaf blight (BB), caused by Xanthomonas oryzae pv. oryzae (Xoo), being a major biotic threat. BB can cause yield losses ranging from 20-80%, with symptoms including Water-soaked spots, pale yellow leaves, and linear yellowish-brown lesions. The disease thrives in warm, humid conditions, particularly in irrigated and wetland ecosystems. Management strategies for BB include chemical control, biological control, and host plant resistance. Among these, host plant resistance, governed by resistance (R) genes such as Xa4, Xa21 and xa13 offers an eco-friendly and sustainable solution. Also yield improvement remains a central goal in rice breeding programs, challenged by stagnation due to environmental stresses and suboptimal agronomic practices. It is a complex quantitative trait influenced by genetic and environmental factors, is determined by both direct traits (e.g., grain weight) and indirect traits (e.g., plant height, panicle length). Recent advances in molecular and conventional breeding have enabled the identification and utilization of yield-enhancing genes like Gn1a, sd1, and GS3, contributing to significant yield gains. Intorsion of these genes through MAS helps in accelerated breeding. These advancements highlight the transformative potential of integrating molecular and conventional breeding approaches to unlock genetic yield potential and drive sustainable agricultural productivity.