IDENTIFICATION AND DEVELOPMENT OF POLYMORPHIC EST-SSR MARKERS BY SEQUENCE ALIGNMENT IN PEPPER, CAPSICUM ANNUUM (SOLANACEAE)

Premise of the study: The redundancies in expressed sequence tags (ESTs) in the National Center for Biotechnology Information sequence database were used to identify and develop polymorphic simple sequence repeat (SSR) markers for pepper (Capsicum annuum). Methods and Results: Sixty-eight polymorphic SSR loci were identified in the contigs (containing redundant ESTs) generated by assembling 118 060 pepper ESTs from the public sequence database. Thirty-three SSR markers exhibited polymorphism among 31 pepper varieties, with alleles per SSR marker ranging from two to six. The mean observed and expected heterozygosity were 0.28 and 0.39, respectively. There were 18 SSR markers with a motif repeat number of less than five, accounting for 55% of the total. Conclusions: We demonstrated the value of mining the redundant sequences in public sequence databases for the development of polymorphic SSR markers, which can be used for marker-assisted breeding in pepper.