콩 소청2호의 균주 특이적인 역병 저항성 유전자좌

Two Isolate-specific Resistance Loci for Phytophthora sojae in the Soybean Socheong2

Phytophthora root rot attributable to infection by the soil-borne oomycete Phytophthora sojae causes serious damage to susceptiblesoybeans grown in poorly drained soil. Management of this disease depends primarily on Rps (resistance to P. sojae) resistance genes. Theobjective of this study was to map resistance to two P. sojae isolates (40412 and 2457) in a Daepung × Socheong2 recombinant inbred linepopulation. Of these two varieties, Socheong2 is resistant to the two isolates, whereas Daepung is susceptible. Single-marker analysis of varianceand linkage analyses using a high-density genetic map identified different resistance loci for each isolate. A genomic region of 36.2~37.4Mbp on chromosome 3 was identified as being associated with resistance to isolate 40412, explaining 18% of the phenotypic variance (PV),whereas, a 2.1~2.6-Mbp region on chromosome 18 was significantly associated with resistance to isolate 2457, accounting for approximately26% of the PV. An additional region of 53.1~53.3 Mbp on chromosome 18 was also significantly associated with resistance to isolate 2457. All three loci coincide with genomic regions where an Rps gene or partial resistance have been mapped in previous studies. The respectivelocus showed significance for only one or the other of the isolates, indicating an isolate-specific interaction. From this finding, it can beinferred that isolates 40412 and 2457 are characterized by different avirulence genes, and that Socheong2 has at least two Rps genes thatinteract with each isolate. The finding of multiple Rps loci specific to an isolate within a single soybean genotype is a unique discovery. Socheong2 will accordingly be a useful genetic source for breeding resistance to multiple P. sojae isolates.