ICAR x Indian Journal of Agricultural Sciences 81 (5): 402–6, May 2011 Genetic diversity and interrelationship among clusterbean (Cyamopsis tetragonoloba) genotypes for qualitative traits RAKESH PATHAK 1 , MANJIT SINGH 2 and A HENRY 3 Central Arid Zone Research Institute, Jodhpur, Rajasthan 342 003 Received: 4 November 2009; Revised received: ABSTRACT A study was conducted during 2006–07 to assess the extent of genetic variability and qualitative characters of clusterbean (Cyamopsis tetragonoloba L. Taub.). The range, genotypic and phenotypic coefficient of variation, heritability, genetic advance and correlation among 7 qualitative characters were estimated in 40 genotypes of cluster bean. The genotypes showed considerable amount of variability for all the traits. Irrespective of their place of collection the genotypes were grouped into 7 different clusters. Cluster analysis revealed that genotypes ‘HGS 884’, ‘HGS 26–01’ and ‘HGS 02–20’ will be useful for genetic resources. High magnitude of heritability and genetic advance for gum, fibre and protein contents suggested that the genotypic variation in the present material for these characters is due to high additive genetic effects. Carbohydrates were positively correlated with endosperm and gum contents. Endosperm exhibited significant positive association with gum content while the association of protein was negative with gum and endosperm contents. Key words: Cyamopsis tetragonoloba, Correlation, Genetic divergence, Proximate analysis Based on a part of PhD thesis of the first author submitted to Jai Narain Vyas University during 2008 1 Technial Officer (e mail: pathakjodhpur@gmail.com), 2 Director, Directorate of Mushroom Research, Solan, H.P. (e mail: directordmr@gmail.com), 3 Principal Scientist (Plant Breeding) (e mail: ahenry@cazri.res.in), Division of Plant Improvement, Propagation and Pest Management Genetic variability is the basis of species’ conservation (Banerjee et al. 2007, Zhao et al. 2006). Knowledge of genetic divergence among the varieties has immense importance for plant breeders. The use of diverse germplasm as a significant factor contributing to high yield and quality characteristics has been stressed by many workers using various crops (Gopala Krishnan and Dwivedi 2008, Medici et al. 2005). Large variability in the initial breeding material ensures better chances of producing new desired forms of a crop. Clusterbean [Cyamopsis tetragonoloba (L) Taub.] belongs to the family leguminaceae and subfamily paplionaceae. It is an annual with long and deep root and well developed laterals, cultivated mainly as rainfed crop in arid and semi- arid regions during rainy (kharif) seasons for vegetable, forage and green manure. India is one of the main producers of cluster bean accounting 80% of the total production of the world, whereas Rajasthan occupies the largest area (82.1%) under guar cultivation in the country. In addition to its cultivation in India, the crop is also grown as a cash crop in other parts of the world (Pathak et al . 2010). The dicotyledonous seed of cluster bean from the outside to the interior consists of three major fractions, viz the husk or hull (14–17%), endosperm (35–42%) and germ (43–47%). The endosperm fraction of cluster bean seed is rich in galactomannan that ranges between 16.8 and 30.9%, while the germ and hull portion termed as guar meal obtained after the extraction of gum is rich in protein (approx. 28.9–46%) and used as animal and poultry feed (Lee et al. 2004, Rodge 2008). Seed of cluster bean has rather a large endosperm unlike most of other legumes and contains galactomannan type of gum, which forms a viscous gel even in cold water and has diversified industrial applications, viz. paper, food, cosmetics, mining, petroleum, well drilling, pharmaceuticals, etc. (Pathak et al. 2009, Senapati et al. 2006). Clusterbean gum has emerged as the most important agro-chemical, which is non-toxic, eco-friendly and Generally Recognized As Safe (GRAS) by FDA. Foreign exchange earned from its export has increased from 142 crores in 1994 to 1120 crores during 2007 in India (Henry and Mathur 2008). Meager information is available for genetic variability in cluster bean addressing the qualitative traits. Studies were therefore, undertaken to assess the extent of genetic variability and association of qualitative characters, viz endosperm, gum, fibre, fat, protein, ash and carbohydrates downloaded from http://epubs.icar.org.in