Amplification and detection of polymorphic sequence-tagged sites in Lathyrus sativus

A simple procedure was developed to convert Lathyrus sativus defence-related expressed sequence tags (ESTs) into mappable genetic markers by using PCR. Twenty-nine STS primer pairs were generated on the basis of sequence information from an L. sativus cDNA library. These primers were used to screen for polymorphisms between 2 L. sativus accessions, ATC 80878 and ATC 80407, resistant and susceptible, respectively, to Mycosphaerella pinodes infection. All 29 primer pairs amplified PCR products in both accessions, 11 of which amplified multiple RAPD-like products. The remaining 18 primer pairs amplified single monomorphic products. Following cloning, sequencing, and database searches, 17 of 18 PCR products were confirmed to have amplified the targeted genome region. Ten of these 17 STS primer pairs revealed polymorphisms between ATC 80878 and ATC 80407 when PCR products were digested with a range of restriction endonucleases. These results suggest that the STS-based PCR analysis will be useful for generating informative molecular markers in L. sativus for future genome mapping experiments.