Genetic uniformity of varieties and an assessment on the diversity among the elite varieties of rice (Oryza sativa L.)

Abstract

The concern that artificial selection for crop improvement leads to loss of genetic diversity, has been debated over the past. The knowledge about the diversity present within the released varieties was important for the direction of future breeding programmes. This experiment was conducted utilizing thirty two elite rice varieties released by Tamil Nadu Agricultural University and that are available in the Breeder’s Seed Production chain of Tamil Nadu. The study was conducted at the Paddy Breeding Station of Tamil Nadu Agricultural University. The contribution of characters to divergence and clustering of varieties accordingly were estimated using Mahalanobis’ D2 statistics and PCA analysis. Time to maturity, single plant yield and days to 50 per cent flowering contributed maximum to the genetic diversity as given by the per cent contribution to divergence. The varieties were grouped into seven diverse clusters. According to Principal Component analysis first three components contributed to 77.3 per cent variability. First component was partitioned among single plant yield, the number of panicles per plant and time to maturity which made 40.6 per cent variability. This study shows that the genetic diversity are being preserved in different varieties indirectly in breeding for different consumer preferences, ecosystems and climatic conditions.

Keywords

• varieties
• rice
• diversity
• d square
• pca
• clustering