Tropical Grasslands (1992) Volume 26, 156164
Identification of selected cultivars and accessions of Stylosanthes by isozyme analysis
V. VITHANAGE and S. CHAKRABORTY
CSIRO Division of Horticulture and Tropical Crops and Pastures, respectively, Brisbane, Queensland, Australia.
This paper establishes standard isozyme patterns for cultivars and selected accessions of Stylosanthes scabra, S. guianensis and S. hamata using seeds from single plants. A total of 9 isozyme systems with 13 isozyme loci were investigated. The banding patterns were used to discriminate among all cultivars of S. scabra and S. guianensis and the cv. Verano from the other cultivars and accessions of S. hamata. All accessions and cultivars of S. scabra and S. guianensis showed differences at a number of loci ranging from 1 to 6. The isozyme patterns obtained for the leucine amino peptidase-2 (LAP-2) and isocitrate dehydrogenase (IDH) were sufficient to place the cultivars into species groups. Markers developed on single seeds from single plants were used to detect differences, both within and between cultivars or accessions. These differences were restricted to either one or two of the three isozyme systems, acid phosphatase (ACP), phospho-gluco isomerase (PGI-2) and LAP-2. In S. hamata, one seed lot of cv. Amiga and two seed lots of cv. Verano showed intra-seed lot differences in ACP. In S. scabra, one seed lot of accession CPI 55857 showed differences in ACP and PGI-2. In S. guianensis, one seed lot of cv. Cook showed differences in PGI-2 isozyme. This genetic variability is thought to have been caused by outcrossing.