Generation of distinct profiles of rice varieties based on agro-morphological characters and assessment of genetic divergence

Twenty-eight rice varieties were evaluated for distinctiveness based on morphological DUS descriptors. Out of 46 visually assessed characters, 14 were monomorphic, 11 dimorphic and the remaining 21 were polymorphic in nature, indicating their potential for variety identification. The expression of each character was found to be stable in both the seasons in all cultivars, thereby emphasizing their consistency. Unique identification profiles were generated on the basis of grouping characters prescribed by DUS Guidelines of PPV & FR Authority. However, distinctive profiles were obtained for 12 varieties only and rest of the 16 varieties remained in six different groups and no further distinctive profile could be obtained. Hence, the morphological DUS descriptors were successful for identification and grouping of varieties up to a certain extent only. The 11 agro-morphological traits were used to assess the variability of these varieties using Ward's Minimum Variance Cluster Analysis which helps in the assessment of pattern and extent of variation in the germplasm. Twenty-eight cultivars were grouped into three clusters revealing sufficient amount of variability among the genotypes. Days to 50% flowering and plant height contributed considerably, accounting for 61% of total divergence. Information, thus, generated through cluster analysis can be efficiently used in breeding rice varieties harbouring desirable traits.