Genetic interrelationship of sweet stem sorghum genotypes assessed with simple sequence repeat markers

Abstract

Knowledge of genetic diversity within and among populations provides essential information in employing appropriate management strategies for germplasm conservation and for establishing a successful breeding program. The objective of this study was to evaluate the genetic interrelationships among phenotypically selected sweet stem sorghum genotypes using polymorphic simple sequence repeat (SSR) markers. Eighteen sweet sorghum cultivars were genotyped using 25 selected SSR markers. The number of alleles detected per marker ranged from 1 to 10 with a mean of 4.64 per locus. The number of effective alleles varied from 1 to 6.75 with a mean of 2.9. The observed heterozygosity varied from 0.00 to 0.39 with a mean of 0.16. The inbreeding coefficient varied from 0.11 to 1.00 with a mean of 0.7. The polymorphism information content (PIC) values for all markers ranged from 0.00 to 0.85 with a mean value of 0.56. Sixty-eight percent of the markers used had a PIC value > 0.50. Analysis of molecular variance revealed highly significant differences (p < 0.001) among the test population. Among and within individual variances contributed to 78% and 21% of total genetic variance, respectively. Based on SSR analysis and agronomic traits, genotypes AS391, SS27, AS204 and AS244 were selected to breed for biofuel production.

Keywords:

• biofuel
• Sorghum bicolor
• SSR markers
• yield component