Biochemical and molecular markers for establishing distinctiveness of aromatic rice (Oryza sativa L.) varieties

Use of biochemical and molecular markers in DUS testing for establishing distinctiveness as a complement to morphological descriptors has been attempted in this study. Twenty indigenous aromatic rice (Oryza sativa L.) varieties were studied for morphological descriptors, total soluble proteins and isozymes as biochemical and RAPD molecular markers for determining distinctive features. SDS-PAGE for total soluble proteins and isozyme analysis revealed moderate and moderate to high degree of polymorphism respectively. UPGMA analysis of combined isozyme data of different enzymes could discriminate all varieties except Bindli from Tilakchandan and two related varieties of Tilakchandan. In general neither morphological descriptors nor biochemical markers could discriminate especially related indigenous varieties of a particular group. A high degree of polymorphism was detected among the twenty aromatic rice varieties through 9 random primers used for RAPD marker analysis. UPGMA cluster analysis of RAPD data could distinguish all the twenty rice varieties. It can be concluded that in situations where the morpho-physiological DUS descriptors are not able to establish distinctiveness of a variety then biochemical and molecular markers may be used as additional or complement descriptors for resolving distinctiveness of indigenous related varieties.