Isozyme variability in Trifolium alexandrinum accessions

Abstract

The present investigation was carried out on 65 accessions of berseem (Trifolium alexandrinum) to estimate the genetic variability based on five enzymes – peroxidase, acid phosphatase, esterase, super oxide dismutase and glutamate oxalo acetate transaminase using starch gel electrophoresis. A similarity matrix showed 95-100% similarity among 64 accessions. Accession EC 329299 belonging to ‘Saidi’ ecotype showed 79% similarity with other accessions. The accessions grouped in three major clusters based on the cutting points in the dendrogram at root level. However, phenetic line drawn at 98% identified 25 groups comprising of 1 to 10 accessions. Of these, 13 groups with more than one germplasm lines showed 100% similarity. Morphologically distinct accessions (i.e. multifoliates and red flowered) formed one cluster. Monomorphic bands (13 out of 26) were in high number. Exotic accessions also showed close similarity to many indigenous accessions which indicated less genetic variability among the germplasm lines introduced from other countries. Polymorphism was recorded for 13 bands (2 for SOD, 3 for GOT, 1 for ACP and 7 for Peroxidase).