Genetic Diversity among Elite Sorghum Inbred Lines Assessed with Simple Sequence Repeats

Abstract

DNA markers are being increasingly utilized in cultivar development, quality control of seed production, measurement of genetic diversity for conservation management, varietal identity, and to assist in maintenance of intellectual property protection (IPP). The use of simple sequence repeats (SSRs) for variety profiling can provide high discrimination, with excellent reproducibility at less cost than for restriction fragment length polymorphisms (RFLPs). The objective of this study was to evaluate the potential utility of SSR technology for applications in research, product development, seed production, and genetic resource conservation management for sorghum. Fifty genetically diverse elite sorghum [Sorghum bicolor (L.) Moench] inbreds were used to compare the discrimination abilities of 15 SSR primers with 104 RFLPs and to compare the associations among lines revealed by these molecular data and by pedigrees. RFLP data allowed all lines to be uniquely identified; two lines could not be distinguished by the SSR data. The mean polymorphism information content (PIC) values were 0.62 (RFLPs) and 0.58 (SSRs). Correlations for pairwise molecular profile distances with pedigree distances among the maintainer female (B) lines were 0.52 and 0.53 for RFLP and SSR data, respectively; data for the male parental restorer (R) lines were 0.41 and 0.47. This set of SSRs could be used to help genetic conservation management and to support IPP. Data from additional SSRs that collectively cover more of the genome will be required for applications to assist in breeding.