title: Genetic analysis and molecular mapping of resistance gene to Phakopsora pachyrhizi in soybean germplasm SX6907.
abstract: In this study, Rpp6907, a novel resistance gene/allele to Phakopsora pachyrhizi in soybean, was mapped in a 111.9-kb region, including three NBS-LRR type predicted genes, on chromosome 18. Soybean rust caused by Phakopsora pachyrhizi Sydow has been reported in numerous soybean-growing regions worldwide. The development of rust-resistant varieties is the most economical and environmentally safe method to control the disease. The Chinese soybean germplasm SX6907 is resistant to P. pachyrhizi and exhibits immune reaction compared with the known Rpp genes. These characteristics suggest that SX6907 may carry at least one novel Rpp gene/allele. Three F2 populations from the crosses of SX6907 (resistant) and Tianlong 1, Zhongdou40, and Pudou11 (susceptible) were used to map the Rpp gene. Three resistance responses (immune, red-brown, and tan-colored lesion) were observed from the F2 individuals. The segregation follows a ratio of 1(resistance):2(heterozygous):1(susceptible), indicating that the resistance in SX6907 is controlled by a single incomplete dominant gene (designated as Rpp6907). Results showed that Rpp6907 was mapped on soybean chromosome 18 (molecular linkage group G, MLG G) flanked by simple sequence repeat (SSR) markers SSR24 and SSR40 at a distance of 111.9 kb. Among the ten genes marked within this 111.9-kb region between the two markers, three genes (Glyma18g51930, Glyma18g51950, and Glyma18g51960) are nucleotide-binding site and leucine-rich repeat-type genes. These genes may be involved in recognizing the presence of pathogens and ultimately conferring resistance. Based on resistance spectrum analysis and mapping results, we inferred that Rpp6907 is a novel gene different from Rpp1 in PI 200492, PI 561356, PI 587880A, PI 587886, and PI 594538A, or a new Rpp1-b allele.
authors: Oil Crops Research Institute of the Chinese Academy of Agricultural Sciences, Wuhan, 430062, China.
authors: Haifeng
authors: H
authors: Chen
authors: Sheng
authors: S
authors: Zhao
authors: Zhonglu
authors: Z
authors: Yang
authors: Aihua
authors: A
authors: Sha
authors: Qiao
authors: Q
authors: Wan
authors: Chanjuan
authors: C
authors: Zhang
authors: Limiao
authors: L
authors: Chen
authors: Songli
authors: S
authors: Yuan
authors: Dezhen
authors: D
authors: Qiu
authors: Shuilian
authors: S
authors: Chen
authors: Zhihui
authors: Z
authors: Shan
authors: Xin-an
authors: XA
authors: Zhou
mesh_terms: D001487:Basidiomycota; D002874:Chromosome Mapping; D032461:Chromosomes, Plant; D060467:Disease Resistance / Q000235:genetics*; D017343:Genes, Plant; D005819:Genetic Markers; D005838:Genotype; D018895:Microsatellite Repeats; D010641:Phenotype; D010935:Plant Diseases / Q000235:genetics / Q000382:microbiology; D013025:Glycine max / Q000235:genetics* / Q000382:microbiology
chemical_list: D005819:Genetic Markers