CHARACTERIZATION OF TOMATO GERMPLASM THROUGH SEED STORAGE PROTEIN PROFILING BY SDS-PAGE

Abstract

The 24 tomato genotypes, including 5 hybrids (Avinash-ΙΙ, CKD-1092, CKD-1093, CKD-1695, CKD-1088), seven germplasm lines (07039, 09091, 27-07, 42-07, 07011, 09076, 09078) and twelve cultivars (Excellence, Nagina, Naqeeb, Advanta-1202, PTM-1431, Pakit, Rio Grande, Lyp#1, Roma, Continental, VCT-Ι, Peto-86), were analyzed by SDS-PAGE for total soluble seed storage proteins on 10% gels. A low level of variability was observed in protein profiles of tomato genotypes. Dendrogram based on electrophoretic data clustered the 24 genotypes in four major groups. All germplasm lines illustrated identical profiles, therefore could not be differentiated on the basis of seed storage protein profiles. However, among tomato cultivars, VCT-l found to be the most divergent and could be distinguished from others on the basis of two peptides i.e. 58 kDa and 15 kDa. Similarly, in case of hybrids, a peptide of 58 kDa was absent in Avinash while present in all other hybrids. Another peptide of 64 kDa was unique to Avinash and absent in all other hybrids. Therefore, among hybrids, Avinash can be distinguished rom others based on these peptide differences. Uniprot and NCBI protein databases were searched for already reported and characterized seed storage proteins in tomato. Among 42 resolved peptides, eleven could be identified from databases. On the basis of molecular weight similarity, identified peptides were SSP-83 as Alkaline alpha-galactosidase, SSP-78 as BiP, SSP-66 as vicilin, SSP-64 as DELLA Protein, SSP-58 as SNF1, SSP-41 as SNF4, SSP36 as putative galactinol synthase 1, SSP-33 as Xyloglucan endotransg- ycosylases, SSP-26 as expansin family, SSP-10 as Putative vicilin and SSP-8 as albumin protein. In onclusion, seed storage profiling by SDS-PAGE can economically be used to asses the genetic variation in ifferent tomato genotypes.