Protein profile and species relationship in Trifolium

The genus Trifolium commonly called clovers comprises of 290 annual and perennial species. The important annual types grown in tropical climate are T. resupinatum, T. subterranum and T. alexandrinum. Egyptian clover (T. alexandrinum) is the most important winter season legume of India. Genetic improvement programmes on Egyptian clover have not been substantially successful due to little crossability among species in natural condition or through conventional breeding techniques. Hence, present investigation was carried out with a view to work out the genomic relationship based on protein analysis among various species of Trifolium. Fifteen genotypes representing 12 species of the genus Trifolium were subjected to leaf protein analysis using vertical Polyacrylamide gel electrophoresis system and genetic similarity were estimated. Several species specific bands were also observed such as band numbers 4 and 9 in T. hybridum, band number 10 in T. angustifolium, band number 15 in T. vesiculosum, band number 23 in T. alexandrinum and band number 24 and 26 in T. resupinatum. The similarity matrix showed the maximum similarity of three T. alexandrinum accessions with T. apertum (87% similarity). T. apertum and T. purpureum clustered with four accessions of T. alexandrinum in one cluster. T. alexandrinum along with T. apertum showed 74% similarity with T. purpureum which also showed similarity with T. alexandrinum in terms of its erect nature, branching pattern and profuse growth in isoclimatic condition. T. alexandrinum showed least similarity with T. pratense (26 to 33%) followed with T. hybridum (30%) and T. echinatum (37–46%). T. alexandrlnum has 12 bands, out of which 11 are common with T. apertum and 9 common with T. purpureum. Work carried out in this laboratory indicated that the morphological characteristics of T. spertum also closely resembled with T. alexandrinum and its crossability with T. alexandrinum (using embryo rescue) supports the finding of leaf protein analysis that the two species have close affinity.