DEVELOPMENT OF SIMPLE SEQUENCE REPEAT MARKERS TO STUDY DNA POLYMORPHISMS IN SORGHUM AND MILLET CULTIVARS

Abstract

Sorghum and millets are considered to have great economic importance among cereal crops in India. As they are diverse crops, genetic fingerprinting of their varieties requires an effective marker system. Microsatellites, or simple sequence repeats, prove to be the DNA markers of choice as they are comparatively more variable. In this study 7 varieties of sorghum and millets each were selected and estimated for their genetic divergence using PCR-SSR Analysis. The percentage of polymorphism in sorghum ranged from 69% to 86.6% while in millets it ranged from 75 to 85%. Cluster analysis based on Unweighted Pair Group Method with Arithmetic Mean method using Dissimilarity Analysis and Representation for Windows was done. Principal Component Analysis was used to characterize the subgroups of their germplasm set. A two- dimensional scatter plot involving all 7 accessions of sorghum has shown that the first two PCA axes accounted for 39.1% and 26.4 % of the genetic variation among populations while for millets it has shown that the PCA axes accounted 21.2% of the genetic variation amongst populations. Results demonstrate that RAPD analysis can be efficiently applied to assess the genetic diversity and phylogenetic relationship of sorghum and millet germplasm.