Estimation of genetic diversity in low-chill Pyrus Spp. through biochemical characterization

To accentuate the field study, biochemical characterization of total twenty one genotypes of low chill Pyrus spp. including relatives were subjected to leaf protein analysis through SDS-PAGE (Sodium dodecyl sulphate polyacrylamide gel electrophoresis). The leaf protein fragments exhibited appreciable polymorphism amongst the twenty one genotypes used for the study. The maximum numbers of protein bands were resolved in Pant Pear-1, Pant Pear-2, Le Conte and Thumb Pear (25 each), while the minimum number were reported in Pant Pear-13 and Pant Pear-18 (13 each), out of total twenty five protein fragments. The zone B comprised of eight bands with their corresponding molecular weight proteins ranging from above 66 kDa to 29 kDa and the major differences in the protein banding pattern are mainly confined to this zone. The protein bands B₇ and C₅ were found to be present in all the genotypes except Mehal and Pant Pear-9 respectively. Out of twenty five protein bands, ten fragments viz; four fragments (A₁, A₂, A₄ and A₅) of zone A, one fragment (B₂) of zone B and five fragments (C₄, C₅ C₇, C₈ and C₁₀) of zone C were found to be present homogeneously in all the twenty one genotypes. On the basis of UPGMA analysis, twenty one genotypes were categorized into three groups. Cluster one comprised of 3 genotypes namely Pant Pear-18 and Pant Pear-15 and one independent genotypes Pant Pear-13, cluster second comprised of two independent genotypes namely Pant Pear-9 and Mehal, while rest of the genotypes were present in third cluster.