Estimation of genetic diversity using seed storage protein (SSP) profiling in wild and cultivated species of Cicer L

The narrow genetic diversity of chickpea is a serious impediment to modern cultivar creation. Seed storage proteins (SSPs) are stable and have minimal or no degradation when subjected to isolation and SDS-PAGE.

We have characterized SSPs of 436 chickpea genotypes, belonging to nine annual Cicer species, originated from 47 countries by SDS-PAGE and determined the extent of genetic diversity in chickpea through clustering. Based on scoring, a total of 44 bands (10 to 170 kDa) were identified, which were all polymorphic. The least appeared protein bands were 11, 160 and 170 kDa where band of 11 and 160 kDa was present exclusively in wild type. Five bands were present in < 10% of genotypes. Bands appeared in 200-300 genotypes were suggested less polymorphic, on contrary bands present in 10-150 genotypes were suggested more polymorphic. Polymorphism of protein bands in context to their potential functions reported in literature were explored and suggested that the glubulins were most and glutelins were least abundant, whereas albumins with their known role in stress tolerance can be used as marker in chickpea breeding. Cluster analysis produced 14 clusters, interestingly three clusters contained only Pakistani genotypes and thus Pakistani genotypes appeared as a separate entity from the rest of the genotypes.

Our results indicate that SDS-PAGE of SSPs is a powerful technique in determining the genetic diversity plus it is easily adaptable, due to its cost effectiveness in comparison to other genomics tools.