830 International Seminar on "Multidisciplinary Approaches in Angiospenn Systematics" GENETIC DIERGENCEANALYSIS FOR YIELDAND ITS CONTRIBUTING TRAITS IN WHEAT (TRITICUM AESTIVUML.) Subhra Mukherjee, Suparna Gupta, Anirban Maji, S. S. Lakshman, Debsankar Gupta and Niladri Bhowmik Abstract On the basis ofD 2 analysis, 20 genotypes of wheat were grouped into six clusters. Cluster V accompanied highest number of genotypes as 9 followed by cluster I with 4 genotypes and cluster 1I, III and IV with 2 genotypes each, whereas cluster VI included with solitary genotype. Inter cluster distance was maximum between cluster V and VI, closely followed by cluster 1I and VI. While the minimum inter cluster distance was observed between cluster I and IV. Key words: Cluster analysis, Genetic divergence, Wheat, Yield and component characters. Introduction In India, wheat contributes one third of the total food grain production next to rice. The genetic variation present in wheat is due to its interesting evolution pattern and natural hybridization. Selection of diversified plant population and detennination of genetic diversity are the most important criteria for plant breeders. 0 2 statistic is a concept developed by Mahalanobis (1936) is an important tool and technique to assess the genetic diversity. The present investigation was directed to select of wheat genotypes to be used as parents in combination breeding to develop lines potential in terai zone of West Bengal. In this connection an effort was made to assess the genetic diversity among 20 wheat genotypes for selection of parents in hybridization programme to provide desirable segregats in advanced generation. Materials and Methods Twenty wheat (Triticum aestivum L.) genotypes collected from OWR, Kamal, Haryana were grown in the research farm of Uttar Banga Krishi Viswavidyalaya, Pundibari, Coochbehar during Rabi 2006 in randomized block design with four replications. The crop was grown in timely sown irrigated condition with recommended agronomic practices. The observations were recorded from five randomly chosen plants from each replication for the eight characters like plant height (cm), days of heading, days of maturity, tiller per meter, spike length (cm), grain per spike, thousand grain weights (grn) and yield per plot (grn). Analysis of variance for different characters was calculated according to the standard procedures. To estimate the genetic diversity the above mentioned characters were carried out further following Mahalanobis 0 2 statistics (Mahalanobis, 1936).The genotypes were grouped into different classes using Tocher's Method (Rao, 1952). Results and Discussion Analysis of variance indicated significant differences among the genotypes for yield and its contributingtraits, suggesting adequate variability present in the genotypes (Gartan and Mittal, 2003; Gupta et ai., 2002 and Venna et ai., 2006.). Based on the Tocher value, twenty genotypes were grouped into six clusters depending upon the genetic constitution of genotypes (Tablet). Cluster V was accommodated with highest number of genotypes (nine) followed by cluster I (four), cluster II, III, IV with two genotypes each. However, the cluster VI was quite unique having monogenotypic indicating its distinctness from other genotypes with most of the characters studied. The genotypes selected showed greater diversity, due to factors like selection under different environments, heterogeneity, genetic drift and history of selection (Murthy andArunachalam, 1966). So, for hybridization, the selection of parents should be based on genetic diversity besides per se performance and geographical origin as suggested earlier by Gartan and Mittal (2003) and Jag- Shoran et ai. (2005). The maximum inter cluster distance was observed between cluster V and VI closely followed by Cluster II and VI, cluster IV and VI, I and VI, indicating greater diversity among the