DUS characterization of rice (Oryza sativa L.) using morphological descriptors and quality parameters

India has recently enacted Distinctiveness, Uniformity and Stability (DUS) characterization for rice. This paper focuses on DUS characterization using morphological descriptors for 21 rice varieties planted in a randomized block design during two kharif seasons (2007 and 2008). Data were recorded for 60 DUS descriptors (46 qualitative and 14 quantitative) following guidelines from the International Union for the Protection of New Varieties of Plants (UPOV) and the Protection of Plant Varieties and Farmer's Rights Authority (PPV & FRA). Data on quantitative traits were subjected to Combined Over Years Distinctness (COYD) and Combined Over Years Uniformity (COYU) analyses. The descriptors offering the most discrimination were time to 50% heading, decorticated grain shape, and the colour of lemma and palea. The cultivar Sathi, an improved landrace entry, was observed to be the most distinct, with the rarest morphological features. Eight of the 21 qualitative and 8 of the 14 quantitative traits exhibited uniformity as determined by UPOV-recommended levels. Twelve of the quantitative traits were relatively stable as judged by seasonal variation in Phenotypic Coefficient of Variation (PCV) and Genotypic Coefficient of Variation (GCV) values. Finally, the varieties were clustered following the eight grouping characteristics recommended by PPV & FRA. All the approaches clustered the improved landrace entities separately from the conventionally bred varieties.