Genetic similarity among five species of Saccharum based on isozyme and RAPD markers

Genetic relationship among Saccharum species clones was assessed using six isozyme systems and thirteen RAPD primers. Multimeric isozyme profile and polymorphic RAPD markers reflected the genetic complexity of the genus. Clones could be distinguished from one another only based on the esterase profile though species affinities could not be detected using this system. Clonal distinction and intraspecies similarities could be understood using a combination of six isozyme systems studied. Low genetic dissimilarity index within Saccharum and overlapping of isozyme pattern of a few clones with other species were suggestive of continuous variation across Saccharum species. Species affinities as revealed through dendrogram constructed based on Phylogenetic Analysis Using Parsimony indicated closeness between S. barberi and S. sinense and between S. officinarum and S. robustum clones. Relationship between S. spontaneum with S. barberi and S. sinense observed through RAPD analysis supported S. spontaneum based origin of the species. The results of isozyme and RAPD analyses were comparable and agreed to the classically derived evolutionary affinities of the genus.