Abstract:

【Objective】 A new rice bacterial blight resistance gene from the wild rice species Oryza minuta (Acc. No. 101133) was transferred into Oryza sativa L. (IR24). Identification and molecular mapping of the resistance gene was carried out to put it into practical use in the future. 【Method】 A BC2F2 population and its F3, F4 families were used for molecular mapping of Xa35(t), and Bulked Segregant Analysis (BSA) was adopted to survey SSR markers. 【Result】 Through genetic analysis and identification of resistance spectrum, Xa35(t) showed a high level of resistance to PXO61, PXO112 and PXO339, but susceptible to PXO86 and PXO99 after inoculation with five strains of Xanthomonas oryzae pv. oryzae (Xoo), suggesting it is a new dominant bacterial blight resistance gene in the long arm of chromosome 11. With SSR marker analysis, the Xa35(t) locus was mapped to a region of about 1.80 cM. This locus, co-segregated with marker RM144, was 0.7 cM from marker RM6293 on one side and 1.1 cM from marker RM7654 on the other side in rice chromosome 11. 【Conclusion】 Genetic analysis and identification of resistance spectrum revealed that Oryza minuta (Acc. No. 101133) harbors a new rice bacterial blight resistance gene, designated as Xa35(t).

Key words: Oryza minuta')">Oryza minuta, rice bacterial blight, genetic analysis, gene mapping