Screening of Rice Genotypes for Bacterial Blight of Rice under Artificial Inoculation in South Gujarat Conditions

Rice (Oryza sativa L)is considered as queen of the cereal crops because of its importance as staple food of about half of the world’spopulation (Qudsia et al., 2017). India has the world’slargest area and is the second highest producer of rice. Rice is considered one of the most strategic commodities for the world; not only linked with global food security but also closely connected with economic growth, employment, social stability and regional peace (Yadev and Kumar, 2018). The production of rice worldwide in 2023-2024 was about 518.14 million metric tons which increases by 0.87 per cent, whereas the production in India during 2023-2024 was about 134 million metric ton changes by seven percent as compared to production in previous five years. With a production of 118.87 million tonnes and a productivity of 2722 kg per hectares, rice is grown on an area of 43.66 million hectares in India (Anonymous, 2021). As opposed to Gujarat, where rice is grown on 0.90 million hectares, producing 2.14 million tonnes and yielding 2365 kg per hectare (Anonymous, 2022). In terms of its nutritional content, over two billion people in Asia alone derive 80 percent of their energy needs from rice, which contains 80 percent carbohydrates, 7–8 percent protein, 3 percent fat, and 3 percent fibre (Chaudhary et al., 2018). In tropical and subtropical rural and urban settings, rice accounts for between four percent and 70 percent of caloric intake (Hossain and Fischer, 1995). A report suggests that the history of domestication and cultivation of rice in China as old as 7700 years (Zong et al., 2007). The bacterial leaf blight disease of rice caused by Xanthomonas oryzae pv. oryzae and causes a huge loss in terms of quantity and quality of rice. In world, due to this disease yield loss was estimated approx 50 percent (Shekhar et al., 2020) and in India 81.3 percent (Prasad et al., 2018; Swati et al., 2015). Bacterial leaf blight early symptoms appear on the leaf blades at tillering stage, starting from lower plant parts and then reaching to above ones (Goto, 1992, Cha, 1982). Inmost damaging cases, yellow to white stripes are seen just inside the margins of the leaf blades, turning yellow and at the end results in mortality of leaf tissues (Ou, 1985). At the seedling stage, the “Kresek” phase is the most damaging phase of bacterial blight (Chahal, 2005). Rice farmers worldwide experience significant yield losses due to bacterial blight. This disease, which is prevalent in the southern region of Gujarat, appears annually, causing substantial damage to rice crops.