Glycine max strain:PI399073 Genome sequencing

Phytophthora root and stem rot (PRR) caused by Phytophthora sojae Kaufm. & Gerd. is one of the most damaging diseases of soybean and management is principally done by planting cultivars with race-specific resistance (Rps genes). A novel Rps gene was identified in the South Korean landrace PI 399073 and mapped to a region on chromosome 13. The objective of this study was to identify tightly linked molecular markers to facilitate its introduction into high yielding adapted cultivars. Resistance to P. sojae isolate OH25 was evaluated with eight separate Williams (rps8/rps8) x PI 399073 (Rps8/Rps8) populations, of which the phenotypic ratios were highly skewed. In a graphical genotype generated from three Williams x PI 399073 BC4F2 populations, Rps8 and resistance to P. sojae isolate Butmu was associated with a 2.23 Mbp region on chromosome 13. Next generation sequencing was subsequently used to assemble ~90% of the 2.23 Mbp in PI 399073.