ỨNG DỤNG CHỈ THỊ PHÂN TỬ LIÊN KẾT VỚI CÁC GEN Xa7, Xa21 ĐỂ TẠO VẬT LIỆU KHỞI ĐẦU PHỤC VỤ CHO CÔNG TÁC CHỌN TẠO GIỐNG LÚA KHÁNG BỆNH BẠC LÁ

In this study, a total of 14 SSR markers linked to two major resistance genes for bacterial blight, Xa7 and Xa21, was used for DNA polymorphism survey among BB resistant gen donors and susceptible but elite rice varieties. The investigation showed that two markers P3, RM20573, and a marker pTA248 were appropriate markers for screening the offspring generation introgressed two major resistance genes, Xa7 and Xa21, respectively. The introgression of these two resistance genes was determined on two BC2F2 backcross populations, derived from the donor, IRBB62 (containing three major resistance genes Xa4, Xa7 and Xa21) and two recurrent parent, BC15 and Hoa Sua (HS). The results showed that, for the BC15/IRBB62// BC15 population, there were two plants containing single resistance gene, Xa7, one plant with two resistance genes Xa7 and Xa21, and all of these genes were heterozygous. Out of 36 individuals from the population HS/IRBB62//HS, 15 plants harbor single gene, Xa7 as homozygous, 5 plants harbor single resistance gene, Xa21 as heterozygous, and 8 plants carried both genes, Xa7 and Xa21. This is very important material source for the research on bacterial blight resistance in rice breeding in the near future.