Phylogenetic Analysis of Cucurbita pepo Using Molecular Markers

A total of 20 squash genotypes were characterized using four isozymes (catalase, peroxidase, esterase, and glutamate oxaloacetate transaminase [GOT]) and protein SDS-PAGE. Electrophoretic analyses of the isozymes exhibited a maximum of 67 bands, indicating a high level of genetic differences. Relative fronts (RF) for the isozymes ranged from 0.126 to 0.824. Polymorphic bands were observed within all the genotypes for all the isozymes examined, revealing 28 positive unique bands within 15 of the 20 squash genotypes. Protein SDS-PAGE analysis showed 62 polymorphic bands among the squash genotypes, ranging from 360 to 8 kDa. From four squash genotypes, six positive, unique bands were obtained. The highest similarity matrix of the protein SDS-PAGE was 91.7% between Dakahlia 1 and Gharbia 2, while the lowest similarity was 8.3% between Giza 1 and Beheira 4. The results indicated the possible application of isozymes and protein spectra as biochemical markers in detecting genetic diversity for use in plant breeding.