Comparison between random amplified polymorphic DNA (RAPD) and simple sequence repeat (SSR) markers with high resolution melt analyses in genetic variation analysis among selected sorghum genotypes

Abstract

Understanding the genetic diversity of germplasm is essential in plant breeding programmes and germplasm management. Molecular markers are efficient and effective tools widely used for assessing genetic diversity among crop genotypes. Recently, high resolution melt analysis (HRM) has been reported for detecting genetic variability. However, there is limited information on the use of HRM in conjunction with other molecular marker techniques for assessing genetic variation in sorghum [Sorghum bicolor (L.) Moench]. This study was conducted to compare random amplified polymorphic DNA (RAPD) and simple sequence repeat (SSR) markers with HRM analyses to determine genetic variation among selected sorghum genotypes. Eight diverse sorghum accessions obtained from the plant genetic resources, Department of Agriculture, Forestry and Fisheries/South Africa were subjected to both analyses. DNA was extracted from fresh leaves of the eight accessions and amplified using three RAPD and three SSR primers. The HRM analysis was performed and temperature normalised melting curves and difference plots were created and results compared. Both the molecular markers and HRM revealed variations among the accessions. The HRM melting profiles fairly well correlated with results from the RAPD and SSR analysis. The clustering of sorghum accessions using SSR marker highly corresponded with the HRM analysis. Therefore, the HRM can be a useful tool in genetic diversity and classification of sorghum genotypes without post-PCR analysis or processing.

Key words: Genetic diversity, high resolution melt analysis, RAPD, simple sequence repeat, sorghum.