Mas Breeding Of Rice Resistance Xa23 To Bacterial Blight And Anther Culture

RM206 is a PCR(SSR) marker linked to the Xa23 gene resisting rice bacterial blight (BB), In this paper, some issues about genetic polymorphism, the condition of gene segregation and rice breeding of resistance to BB are discussed in 386, 384, 385, 387 and F1, F2, F3, F4, BC1, BC2 Population of (384x386), (385x386), (387x386) . At the same time, the materials of F2 containing RM206 were cultured. The results are following.(1) The results show that RM206 represents a good polymorphism among the materials studied, and the gene segregation coincides with the law of gene segregation in F2, BC1, BC2. Therefore MAS of Xa23 is a accurate approach in rice breeding.(2) 384,385,387 are susceptible to BB with some good agronomic traits. 386 contains dominant Xa23 conferring resistance to BB. The objective of this study is to improve the BB resistance of 384,385,387 by introgressing Xa23 gene, into 384,385,387 with 386 as the donor RM206 linked tightly with Xa23 as DNA marker. BC1 progenies of containing RM206 identified using PCR screening and with agronomic traits including plant type, grain type and days to heading etc similar to 384 or 385,387,were subsequently backcrossed to 384 or 385,387 and to generate BC2. BC2 were subsequently selected using the same approach. Among the BC1 plants, RM206(Aa) 76, 54,72 plants, were the most samesimilar to 384,385,387 in the agronomic traits. Among the BC2 plants, 110,80,90 plants selected from the fields were amplified by PCR, RM206(Aa) 48,41,38 plants were respectively obtained. The BC2 materials of RM206 obtained will render precious materials to breed the three improved lines 384, 385, 387 .The breeding of the three improved lines can increase resistance to BB.(3) We used RM206 to survey plants of F2, F3, F4, Among the F2 population, RM206 89, 157, 158 plants were respectively obtained. Among the F3 population, RM206 71, 82, 73 plants were respectively obtained. Among the F4 population, RM206 (AA) 11,14, 9 plants were respectively obtained. The F4 materials of RM206 (AA) obtained will render precious materials to breed rice resistant varieties to BB.(4) The materials were selected by MAS from F2 population of (384x386),(385x386),(387x386) and contain RM206. The anther of F2 materials were cultured. 28,47,35 anther callus were respectively obtained from F2 population of (384x386), (385x386) and (387x386).The rates of the callus induction respectively are 0.74%, 0.92%, 0.63%. 1, 2 green plantlets were obtained respectively from the callus of F2 of (384x386),(385x386). The success of haploid plant is key to haploid breeding of these materials. Haploid breeding can shorten the period of rice breeding, and increase selection efficiency.