ANALYSIS ON xa-5 FOR RESISTANCE TO BACTERIAL BLIGHT AMONG RICE LANDRACES IN VIETNAM

In this study, recessive gene xa-5 used as materials for screening leaf blight resistance, using 13 bacterial races at Mekong provinces and compared to check varieties. Bacterial leaf blight caused by the bacterial pathogen Xanthomonas oryzae pv oryzae (Xoo) limits rice yield in all major rice-growing regions of the world, especially in irrigated lowland and rainfed conditions where predisposition factors favor disease development to epidemic proportions. Since bacterial pathogens are difficult to manage, development of host plant resistance is the most effective means of disease management. To combat the problem of resistance breakdown, this study aims at using DNA marker-aided selection (MAS) to detect varieties that have BBL resistance genes such as xa-5. Using SSR marRers namely RM122 and RM13 linRed to xa-5 on chromosome 5; it indicated that MAS provided the very useful information for developing strategies to develop resistance genes in rice breeding programs to improve varieties in Vietnam. Reywords. Bacterial leaf blight, Xanthomonas oryzae pv oryzae