SSR Mapping and Confirmation of Soybean QTL from PI 437654 Conditioning Resistance to Reniform Nematode

Recently, reniform nematode (Rotylenchulus reniformis Linford and Oliveira) has been recognized to be a major problem on soybean [Glycine max (L.) Merr.] in the southern USA. Planting reniform nematode–resistant soybean cultivars is the most cost effective control method. With restriction fragment length polymorphism (RFLP) markers, Pioneer Hi‐Bred International, Inc. had previously identified quantitative trait loci (QTL) on linkage group B1 (LG‐B1) and another on LG‐L associated with reniform nematode resistance in a cross between ‘BSR101’ and PI 437654. In this study, we refined the QTL locations and identified additional QTL conditioning resistance to reniform nematode in a population of 228 recombinant inbred lines (RILs) from a cross of BSR101 × PI 437654. A QTL (R2 = 21%) conditioning reniform reproductive index (RI) was found on LG‐L and was flanked by Sat_184 and Satt513. Two other QTL were identified, one on LG‐B1 (R2 = 16%) and the other on LG‐G (R2 = 8%). These two QTL acted in an epistatic manner with lines homozygous for PI 437654 alleles at both QTL providing the lowest reniform RI. The 31 RILs from BSR101 × PI 437654 that were homozygous for the PI 437654 alleles at Satt513, Satt359, and Sat_168 averaged 1077 reniform eggs and juveniles (RI = 0.63), while the 33 RILs homozygous for the BSR101 alleles averaged 10606 (RI = 6.24). By screening the RILs population of ‘Prichard’ × ‘Anand’ we confirmed that the QTL on LG‐G and‐B1 conditioned reniform RI.