Development of SSR-based sorghum (Sorghum bicolor (L.) Moench) diversity research set of germplasm and its evaluation by morphological traits

摘要

Assessment and utilization of diversity in plant genetic resources is vital for the improvement of plant species. A sorghum diversity research set (SDRS) was developed by using SSR markers. A total of 320 sorghum accessions were selected based on geographic distribution from more than 3,500 germplasm accessions comprising Asia (East, Southeast, South and Southwest Asia) and Africa, conserved at NIAS Genebank, Japan. We selected 38 simple sequence repeats (SSR) markers which generated 146 alleles, covering ten chromosomes of sorghum from a three different published SSR linkage map of sorghum. The average percentage of polymorphic loci (P) and gene diversity (He) observed in this study were 82.8 and 0.217 respectively. Analysis showed a positive correlation with geographic pattern of differentiation. Based on SSR assessment, 107 sorghum accessions were selected as diversity research set. There was no significant difference in pattern of genetic spectrum between SDRS and base population. Similarly no greater change was observed for variability parameters (Dice, %P, He) and almost all of the SSR alleles were retained in selected sorghum accessions except for the loss of a single allele at locus Xtxp287. SDRS was sown during sorghum sowing season in two replications. Data were recorded on 26 important morphological traits according to the standard sorghum descriptors at Genebank. Analysis of variance showed a highly significant difference among all accessions for all of the traits. Morpho-agronomic traits could not effectively classify the accessions according to geographic origin by using cluster analysis.