Assessment of somaclonal variation and stability inIn vitroregenerated grasspea plants using SDS-PAGE

Abstract

Tissue culture may be one of the possible sources of variation for crop improvement. To assess variation and stability in regenerated plants, shoots were regenerated from the callus derived from axillary explants of 11 grasspea genotypes, and their shoot protein profiles were compared with those of seed cultured plants. The highest response of callus induction (87%) was observed when 2.0 mg/l2,4-dichlorophenoxyacetic acid(2,4-D) and 0.25 mg/l BAP were supplemented in Murashige and Skoog’s (MS) medium. a-naphthaleneacetic acid(NAA) and 6-benzylaminopurine(BAP) showed variable redifferentiation response along with callus formation. The MS medium supplemented with 0.5 mg/l BAP showed better multiplication and elongation of shoots.Sodium dodecyl sulphate polyacrylamide gel electrophoresis (SDS-PAGE) analysis showed a unique protein band of 43 kDa in both tissue and seed cultured plants of Pusa 24. Polypeptide banding pattern of regenerated plants from 11 grasspea genotypes did not deviate from the banding pattern of parental seed protein. Similarity coefficient values ranged from 0.37 to 0.85 with a mean of 0.43 among the 55 genotypic combinations. Comparison of protein bands between calli raised regenerated shoots and parental seeds revealed the absence of somaclonal variation in regenerated plants, suggesting that the regeneration protocol used in the present study can be used for genomics enabled improvement in grasspea without the risk of additional variation or instability.