Identification of bacterial blight resistance gene Xa7 in rice (Oryzae sativa L.) through STS marker.

Bacterial blight caused by Xanthomonas Oryzae pv. Oryzae (Xoo) is the most destructive disease of rice that limits rice yield in all major rice-growing regions of Pakistan, especially in irrigated lowland conditions. Since bacterial pathogen is difficult to manage, development of host plant resistance is the most effective mean to control this disease. In this investigation, a major gene (Xa-7) conferring broad spectrum resistance to various races of the pathogen has been identified in various varieties and advance lines of rice by STMS marker. Out of 74 rice varieties, 31 to 44 showed the presence of Xa-7. Identification of Xa7 gene in rice could be utilized for increasing the level of resistance of existing rice varieties.