Hindawi Publishing Corporation ISRN Genetics Volume 2013, Article ID 651019, 6 pages http://dx.doi.org/10.5402/2013/651019 Research Article Genetic Divergence in Indigenous Wild and Cultivated Rice Species of Manipur Valley K. Medhabati, 1 K. Rajiv Das, 2 M. Rohinikumar, 3 H. Sunitibala, 1 and Th. Dikash Singh 1 1 Medicinal Plant and Horticulture Division, Institute of Bioresources and Sustainable Development, Takyelpat, Imphal 795001, India 2 Department of Environmental Biotechnology, Bharathidasan University, Tiruchirappalli 620024, India 3 Director of Research, Central Agricultural University, Iroisemba, Imphal 795004, India Correspondence should be addressed to K. Medhabati; m_kangabam@yahoo.co.in Received 25 August 2012; Accepted 19 September 2012 Academic Editors: J. Huang and D. Sun Copyright © 2013 K. Medhabati et al. is is an open access article distributed under the Creative Commons Attribution License, which permits unrestricted use, distribution, and reproduction in any medium, provided the original work is properly cited. Genetic divergence of 32 indigenous rice germplasms and �ve wild rice of which three from Manipur and two wild rice procured from IRRI, Philippines was investigated using Mahalanobis,  2 statistic. Based on twelve agromorphological characters, the thirty- seven germplasms both wild and cultivated were grouped into �ve clusters based on the relative magnitudes of  2 values following Tocher’s method of cluster formation. Based on the rank totals, the characters which contributed maximum towards genetic divergence in the present studies were grain yield/plant, spikelet/panicle, 100 grain weight, grain length, days to 50% �owering, ear bearing tillers/plant, and �ag leaf length. In the present study, maximum intercluster distance was estimated between cluster III and (   2 = 14.09) which was closed followed by clusters II and V (   2 = 12.50). On the basis of their greater intercluster distance, high value of cluster mean according to the character to be improved and performance of the individual germplasms for the character, the germplasms could be used in hybridization programme for improvement of different plant characters in the rice germplasms of Manipur. 1. Introduction Manipur valley which is also considered as rice bowl of the state has a large variability of indigenous rice cultivars that belong to Asian cultivated rice O. sativa L. subspecies indica. So far, 44 indigenous rice cultivars along with two wild rice wainuchara one with perennial form and murshi another with annual weedy form have been recorded from Manipur valley by Singh and Sharma [1]. If one considers the percentage availability of indigenous rice cultivar per unit area Manipur valley has one land race of rice per 42 sq⋅km. According to traditional classi�cation, more than 50 rice cultivars were cultivated in Manipur valley before the introduction of high-yielding varieties bred in Manipur. e high-yielding varieties of rice introduced from the plain or hill regions of the northern and southern parts of the country do not perform well in northeastern hill region [2]. e importance of local land races of rice in breeding programme lies in the evolution of gene complexes in the local cultivars that have coadapted to speci�c local environment through long period of natural selection. ese gene complexes may not be readily reconstituted even by the modern recombinant DNA technology; we have to utilize the naturally occurring gene complexes for breeding of rice for speci�c local condi- tions. e basic importance of genetic diversity in breeding for high yield has long been recognized as is evident from the results reported by several workers in different crops. e magnitude of heterosis in crop plants depends on the degree of genetic divergence between parental stocks and, consequently, may be used as an indicator of the inherent yielding capacity of a cross. While the importance of genetic diversity has long been appreciated by breeders, the basic difficulty has always been one of recognizing and estimating such diversity, shortness of actually making the cross. In view of the great importance of genetic diversity to breeding, techniques which can provide direct and reliable quantitative estimates of diversity at the genotypic level should prove to