On-farm Diversity of Indigenous Rice (Oryza Sativa L.) Landraces in Border of Eastern Himalaya

Eastern Himalaya is still unexplored in terms of the traditional rice, a reservoir of qualitative traits. The traditional rice is in serious threats from the social diversion and reduction in agricultural practices. The study was conducted to evaluate the status of the genetic resource of indigenous Rice (Oryza sativa L.) landraces and its diversity. Forty-one rice varieties were reported from diverse elevation exposures. Both univariate and multivariate statistical analysis had provided plenty of evidence on existence of polymorphism. Pearson's correlation of traits revealed 1.8 % of the trait combinations correlated strongly (r = 0.68-1.00), 2.23 % correlated weakly (r <= 0.35), while 5.69% correlated moderately (r = 0.36-0.67). The dendrogram obtained from Euclidian distance and UPGMA (Unweighted Pair Group Method with Arithmetic Mean), revealed three distinct clusters. The cluster analysis using the UPGMA and Euclidean distance revealed the range of genetic distance to be 10 to 757 and obtained three different clusters based on hierarchical clustering. The similarity was observed to be maximum between ACC47 and ACC48 and minimum between ACC46 and ACC49. Out of thirty independent principal components (PCs), top five PCs cumulatively account for 51.74% of the variance. Individual analysis of the factor loadings of the characters in the retained PCs showed that grain related traits have highest positive factor loadings in both PC1 (15.30% of the total variation) and PC2 (16.30% of the variance). While, the first two principal components (PC1 and PC2) cumulatively explained 27.61% of the total variance. The region has a potential for rice genetic resources, which can be a source of impending qualitative traits that can be useful for breeding purposes.