Marker assisted gene pyramiding for blast Magnaporthe grisea resistance in rice Oryza sativa L Cv HUR 4 3

Abstract

Despite the significant increase in the area under rice in the recent years, the newlineyield and productivity level of varieties is greatly affected by many pests and diseases. newlineIn India, bacterial leaf blight and rice blast are the two major diseases which cause newlinesignificant yield losses. Rice blast, caused by Magnaporthe grisea, is one of the most newlinedevastating rice diseases worldwide. The annual loss of rice yield caused by blast was newline10 to 30%, estimated to be enough for feeding and#8776;60 million people. Breeding efforts newlinehave aimed to introduce blast resistance (R) genes into susceptible elite cultivars. newlineHowever, resistant cultivars often remain effective for only a few years due to newlinepathogenic variability of M. grisea. Therefore, breeding for cultivars that display newlinebroad-spectrum and durable resistance has become a priority in rice improvement newlineprograms throughout the world. In order to sustain the yield levels of rice varieties, it newlineis highly inevitable to develop disease resistant varieties and it will be highly newlinedesirable to deploy genes conferring resistance to rice blast in elite rice varieties. newline