Abstract

                                A study was conducted to analyze trait variations among rice genotypes in the Terai region of West Bengal and to select high-performing genotypes based on specific characteristics. The study was conducted during the Kharif (Aman) seasons of 2019 and 2020, focussing on 42 rice genotypes at Uttar Banga Krishi Viswavidyalaya, Cooch Behar, West Bengal. The Mahalanobis D2 analysis revealed four distinct clusters, with significant variation observed for grain length, plant height, and grain yield per plant. Additionally, the maximum Mahalanobis D2 distance was observed for Dudeswar, Baramshall, and Khara. The Principal Component Analysis identified spikelet fertility, grain yield per plant, filled grains per plant, and test weight as principaldiscriminatory characteristics, with Dudeswar exhibiting the highest index score of 2.49. It was followed by Geetanjali with a score of 1.92, according to the Smith selection index. The significant characters identified through the D2 analysis and PCA, such as grain length, plant height, spikelet fertility and others played a crucial role in revealing the diversity among the genotypes. The maximum D2 distances for specific genotypes, coupled with high index scores, suggested a strong association with discriminatory characteristics identified through the Smith selection index, emphasizing their importance in genotypic classification and selection.

Key words : D2 statistic; Genetic diversity; PCA; Rice; Smith index; Terai region