Identification of Anthracnose Resistance Markers in Lentil through Comparative Screening with Marker Sequences from the Model Legume >Medicago truncatula

Abstract

Developing anthracnose-resistant lentil cultivars can reduce labor and chemical costs as well as ensure wide production of lentil. Simple sequence repeat (SSR) markers, expressed sequence tag containing internal simple sequence repeat (EST-SSR) markers, and PCR-based expressed sequence tag (EST) markers that originate from cross-species sequence comparisons to the sequenced genome of the model legume Medicago truncatula (Mt), have enabled the recent development of transferable and function-associated pulse genome analysis. Accordingly, application of markers derived from available Medicago truncatula (Mt) genome sequence information to lentil genome analysis will enhance their critical role in lentil breeding, in particular marker-assisted selection (MAS) for identification of anthracnose resistance gene candi dates. To date, few genes related to this trait have been identified in lentil. The screening procedure for these markers was accomplished by means of polymerase chain reaction PCR amplification of related genes from genomic DNA, which in volved four pools of lentil DNA categorized according to their degree of anthracnose resistance. When compared to the results obtained from the literature on cross-transferability of molecular markers among various plant species, the transferability rate of Mt EST-SSRs, ESTs and SSRs to lentil genomes rates are far higher. In addition, I found no significant differ ences within these marker sets with respect to their transferability rates to lentil. Analysis of polymorphism data indicate lower levels of polymorphisms with EST-SSRs and ESTs than with genomic SSRs, which is in agreement with previous studies. However, my results are not in agreement with those previous studies that reported higher transferability of SSR than EST-SSR markers. Amplicon(s) of these marker sets were further analyzed and characterized with respect their reproducibility, frequency and banding patterns, which showed remarkable comparative genomic differences.