Molecular markers useful for detecting resistance to brown stem rot in soybean

Brown stem rot (BSR) causes vascular and foliar damage in soybean [Glycine mar (L,) Merr.], Identification of plants resistant to BSR by inoculation w ith Phialophora gregata (Allington & W,W, Chamberlain) W, Gams is laborious and unreliable because of low heritability, Molecular markers linked to th e resistance gene could be used to screen for resistant individuals and has ten the development of BSR resistant genotypes. The objective of this study was to develop molecular markers for efficient identification of BSR resis tant plants in a breeding program. Seventeen resistant and 29 susceptible c ultivars and plant introductions as well as recombinant inbred lines derive d from a cross between BSR 101 and PI 437.654 were assayed by PCR-based mar kers derived from RFLPs K375I-1 and RGA2V-1, Satt244, or developed from bac terial artificial chromosome (BAC) sequences. The DNA markers that were dev eloped tag the BSR locus and are informative in a diverse range of soybean germplasm, Markers detected different banding patterns between resistant an d susceptible genotypes, The PCR-based markers will most likely be useful i n screening for BSR resistance and allow soybean breeders to transfer rapid ly resistance derived from Rbs(3) to improved cultivars or soybean lines. T he markers are relatively easy-to-use, inexpensive, and highly informative. Soybean breeding efforts ran now be designed to incorporate the use of mar ker information when parental genotypes possess contrasting banding pattern s.