Development of expressed sequence tags-simple sequence repeats (EST-SSRs) for Musa and their applicability in authentication of a Musa breeding population

Abstract

Maintaining identity of clones is essential in breeding programs. New EST-SSR markers have been developed for banana and used to screen a diploid population for clonal identity. A total of 410 primer pairs were designed from an EST database, validated using polyacrylamide gel electrophoresis (PAGE) and a subset was optimized for accurate genotyping on a capillary genetic analyzer. Combining PAGE and capillary electrophoresis, about 44% of the designed primers were informative in the diploid population. The majority of markers produced two alleles as expected in a diploid population. However, some showed three to four alleles, possibly indicating closely-related members of gene families. Screening of field samples using SSR markers revealed genotype identity issues in the target population. The present study demonstrates the applicability of SSRs in the  establishment of parentage and relatedness between accessions. The newly-developed SSRs will be valuable tools in the understanding of Musa genetics, in marker-trait associations, thereby enhancing the effectiveness of breeding programs.

Key words: EST, SSRs, markers, Musa, breeding.