Studies on proteins and isozymes in aromatic and non aromatic rice

SDS-PAGE of soluble proteins and storage proteins did not reveal any marked differences between the aromatic and non-aromatic varieties of rice. However, isozyme analysis of the two groups of rice varieties showed malate dehydrogenase to be monomorphic while eight other enzymes, viz. alcohol dehydrogenase, aspartate aminotransferase, esterase, glucose-6-phosphate isomerase, glutamate dehydrogenase, peroxidase, phosphoglucomutase and shikimate dehydrogenase to be polymorphic. Glucose-6-phosphate isomerase and peroxidase isozyme patterns were distinct and could be used for distinguishing non-basmati aromatic varieties while phosphoglucomutase isozyme pattern could be useful in identifying the basmati aromatic varieties. Dendrogram constructed, based on isozyme data revealed three major clusters of rice varieties. Isozyme polymorphism may be used for differentiation and identification of rice cultivars and for utilization in a rice varietal improvement programme.