Submitted to: Plant and Animal Genome Conference Proceedings
Publication Type: Proceedings
Publication Acceptance Date: 1/1/2009
Publication Date: 1/10/2009
Citation: Lee, S., Wamishe, Y., Jia, Y., Liu, G., Jia, M.H. 2009. Mapping two major resistance genes in an indica cultivar Zhe733 to the race IE-1K of Magnaporthe oryzae. In: Proceedings of Plant and Animal Genome XVII Conference, January 10-14-2009, San Diego, CA. W506. Interpretive Summary:
Technical Abstract: Resistance (R) genes in rice confer resistance to races of Magnaporthe oryzae that contain the corresponding avirulence genes. The race IE-1K of M. oryzae recovered from the southern US overcomes R gene Pi-ta. The objectives of the present study were to identify new resistance sources to IE-1k and provide genetic map information of the resistance loci in rice chromosomes. Three isolates TM2, S1, and 94071 of the race IE-1k were used to identify R genes from a newly introduced resistant indica rice cultivar Zhe733 using a recombinant inbred line population from a cross of KBNTlpa/1-1 and Zhe733. The ratios of 3 resistant: 1 susceptible in RIL of an F10-11 KBNTlpa/1-1/Zhe733 population indicated that two major R genes in Zhe733 confer resistance to isolates TM2, S1, and 94071. To determine chromosomal locations of the resistance loci to IE-1k, a total of 118 polymorphic Simple Sequence Repeat (SSR) markers were further analyzed in 167 F10-11 RIL of KBNTlpa/1-1/Zhe733 population using composite interval mapping. Two major R genes designated as Pi41(t)/ and Pi42(t)each providing complete resistance to TM2 were identified on chromosomes 8 and 11, respectively. Pi41(t) and Pi42(t) also confer resistance to other US races IB-1, IB-45, IB-49, IB-54, IC-17, IE-1, IG-1, and IH-1. The Pi41(t)/gene is linked to SSR marker RM72 at the genetic distance of 0.9 cM and Pi42(t)/ was 0.2 cM from SSR marker RM1233. RM72 and RM1233 identified in this study should be useful for facilitating the incorporation of Pi4l(t) and Pi42(t) into advanced breeding lines by marker-assisted selection.