Assessment of Sorghum Genetic Resources for Genetic Diversity and Drought Tolerance Using Molecular Markers and Agro-morphological Traits

Abstract

Forty sorghum genotypes were investigated for genetic
diversity and drought tolerance. Diversity parameters were estimated
using 16 Simple Sequence Repeats markers. For assessment of drought
tolerance, the genotypes were field evaluated under normal and drought
stress conditions for two seasons in three environments, in Sudan. In total,
98 SSRs alleles were detected with an average of 6.1 alleles per locus.
The estimated polymorphic information contents ranged from 0.33 to
0.86. The genetic similarity ranged from 0.00 to 0.88 with a low mean of
0.32. The dendrogram, generated from the UPGMA cluster analysis,
showed two main clusters differentiated into nine sub-clusters with close
relationship to morphological characters and pedigree information. Mantel
statistics revealed a good fit of the cophenetic values to the original data
set (r = 0.88). The overall mean genetic diversity was 0.67. Significant
differences were detected among genotypes under both normal and
drought stressed conditions for all measured traits. Based on the relative
yield, the most drought-tolerant genotypes were Arfa Gadamak, Wad
Ahmed, El-Najada, Korcola, ICSR 92003 and Sham Sham. Drought