Genetic Variation in Sorghum Germplasm from Sudan, ICRISAT, and USA Assessed by Simple Sequence Repeats (SSRs)
- A. H. Abu Assara,
- R. Uptmoorb,
- A. A. Abdelmulac,
- M. Saliha,
- F. Ordond and
- W. Friedt *b
- a Agricultural Research Corporation (ARC), P.O. Box 126, Wad Medani-Sudan
b Institute of Crop Science and Plant Breeding I, Heinrich-Buff-Ring 26-32, D-35392 Giessen, Germany
c Department of Crop Production, Faculty of Agriculture, Khartoum North, Shambat 13314, P.O. Box 32
d Institute of Epidemiology and Resistance, Federal Centre for Breeding Research on Cultivated Plants, Theodor-Roemer-Weg 4, D-06449 Aschersleben, Germany
Assessment of genetic variability in crops has a strong impact on plant breeding and conservation of genetic resources. It is particularly useful in the characterization of individuals, accessions, and cultivars in determining duplications in germplasm collections and for selecting parents. The objective of this study was to estimate genetic diversity and to obtain information on the genetic relationship among 96 sorghum [Sorghum bicolor (L.) Moench] accessions from Sudan, ICRISAT, and Nebraska, USA, using 16 simple sequence repeats (SSRs). In total, 117 polymorphic bands were detected with a mean of 7.3 alleles per SSR locus. By this approach each accession is uniquely fingerprinted. Genetic similarity estimates ranged from 0 to 0.91, with a mean of 0.30. The polymorphic information content (PIC) for SSRs ranged from 0.46 (SB4-72) to 0.87 (SBAGF06). Diversity index (DI) for all accessions was 0.71. Within subgroups, DI was 0.63 for Sudanese landraces and improved cultivars, 0.49 for PI accessions, 0.42 for Nebraska derivatives, 0.39 for the ICRISAT advanced breeding lines (ABLs), 0.65 for the Feterita group, 0.71 for the Milo group, 0.63 for a Synthetic group (new breeding materials), 0.68 for the Hegiri group, and 0.47 for the Mugud group. Mantel statistics revealed a good fit of the unweighted pair-grouped method with arithmetic average (UPGMA) cluster to the original genetic similarity (GS) data (r = 0.867). UPGMA clustering produced two main clusters comprising mainly nonimproved germplasm (gene bank accessions and Nebraska population derivatives), and improved genotypes (cultivars, Gadarif collections, and ICRISAT advanced lines). Grouping of accessions by UPGMA cluster analysis matched with the geographical origin and/or pedigree information (Sudan, USA, ICRISAT), the adaptation zone (Gadarif area, Sudan), and morphological characters (Feterita, Mugud, and Milo types), indicating the strong differentiation among the sorghum materials.Please view the pdf by using the Full Text (PDF) link under 'View' to the left.
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