Diversity in sugarcane species and hybrids for peroxidase isozyme

Abstract

Peroxidase isozyme was surveyed in 28 clones belonging to five species ofSaccharum L.and inter specific hybrid. Presence of more number of isozymes inSacharum reflected genetic complexity of this polyploid genus.Saccharum species could be identified from one another by the presence/ absence of specific isozymes. S.officinarum andS. robustum showed lesser genetic diversity.S. sinense was the most complex species with more number of isozymes and could be distinguished from its close relativeS. barberi. S. officinarum clones link Manjri Red, Baragua, Gungera and 57NG77 had isozymes characteristic of other species, as also reflected in the dendrogram, indicating introgression of genes from other sources in their origin. 2n = 64 cytotypes ofS. spontaneum were more similar, but were divergent from the rest including the other cytotypes of the species. F1 hybridity were intermediate between the parents, proving their hybridity. Commercial hybrids showed less diversity with species accessions in support to their interspecific origin. Peroxidase diversity among commercial hybrids quantified in terms of similarity indices may be useful in identifying diverse cross combinations for deriving heterotic hybrids in sugarcane breeding programmes.