77 Indian Journal of Agricultural Sciences 89 (8): 1293–7, August 2019/Article Study of genetic diversity in muskmelon (Cucumis melo) from different horticultural groups B B BHIMAPPA 1 , H CHOUDHARY 2 , T K BEHERA 3 , V K SHARMA 4 , ZAKIR HUSSAIN 5 and B S TOMAR 6 ICAR-Indian Agricultural Research Institute, New Delhi 110 012, India Received: 03 May 2018; Accepted: 12 February 2019 ABSTRACT An experiment was carried out to analyze genetic divergence through multivariate analysis based on D 2 and principal component analysis (PCA) for 24 yield contributing traits among 67 muskmelon (Cucumis melo L.) genotypes from 3 horticultural groups. The 67 genotypes were grouped into 15 distinct clusters. Cluster I consisted of 27 exotic lines from inodorous and cantalupensis group followed by cluster XIVwith 14 genotypes. Majority of genotypes of cluster XIV were developed in India except 4 exotic lines. The remaining13 clusters comprised of only 2 genotypes each and thus clustering pattern indicated enough genetic divergence in the germplasm under study. The highest value of intra cluster distance (43. 68) was found for cluster XV with 2 genotypes followed by XIV (38. 35) possessing 14 genotypes and cluster I (31. 07) having 27 genotypes. The highest inter cluster distance was observed between cluster XV and XIV (42. 24), followed by the cluster XV and XI (40. 70) and cluster XV and VI (40. 48). The frst 3 principal components accounted for majority (53. 77%) of the total variation. The traits which contributed positively to PC1 were days to frst male fower opening, average fruit weight, fruit length, cavity length and yield per plant. The high yielding muskmelon genotypes with better fruit quality traits like DM-31, DM-145, DM-159 and DM-162 from inodorous group of Cluster I and Pusa Madhuras (Cluster VII), Kashi Madhu, Punjab Sunheri, Hara Madhu (Cluster XIV) from cantalupensis group should be utilized for hybrid development between two horticultural groups to incorporate theyield and desirable fruit quality traits from both groups. Key words: Genetic divergence, Muskmelon, Multivariate analysis, Principal component analysis 1 Ph D Student (bhimappahort602@gmail. com); 2,3,4,5 Principal Scientist (harshahit2001@yahoo. co. in), (usar@rediffmail. com), (vksharma. iari@gmail. com), (zakir@iari. res. in); 6 Head and Principal Scientist (bst_spu_iari@rediffmail. com) Division of Vegetable Science, ICAR-IARI, New Delhi. Muskmelon (Cucumis melo L., 2n = 24) is one of the important Cucurbitaceous vegetable grown throughout the world. African continent especially eastern region of south Sahara desert is generally regarded as the centre of origin of Cucumis melo while India has been considered as an important secondary centre of diversity. However, recent studies showed that cucumber and muskmelon are both of Asian origin and wide diversity of this species exists in India and China (Sebastian et al. 2010). Improvement in yield and quality is normally achieved by selecting genotypes with desirable character combinations existing in the nature or by hybridization. Selection of parents identifed on the basis of divergence analysis would be more promising for a hybridization programme. Multivariate analysis has been found useful for characterization, evaluation and classifcation of plant genetic resources when a large number of accessions are to be assessed for several characters of agronomic and physiological importance. Different types of analysis such as cluster analysis and principal component analysis (PCA) can be used to obtain idea about how to identify groups of accessions that have desirable traits for breeding, and enlighten the patterns of variation in the germplasm collection, to identify relationships among accessions and possible gaps. The information usually needed for developing high yielding varieties with better fruit quality in melon pertains to the genetic variability for these specifc traits in the available germplasm for breeding programmes. Multivariate analysis of elite germplasm collections of cucurbits including melons for choosing promising genetically diverse lines for desirable traits have been successful in the past (Choudhary et al. 2003, Mladenovic et al. 2012). But majority of these studies have been limited to a particular horticultural group of melons in India, although there is enough possibility of utilizing germplasm from different horticultural groups for improvement of Indian muskmelon for yield, quality or resistance to biotic stresses. Keeping in view the above facts, the present study was carried out to investigate the extent of genetic diversity in 67 muskmelon genotypes belonging to 3 horticultural groups. MATERIALS AND METHODS The experiment was carried out at the Research Farm https://doi.org/10.56093/ijas.v89i8.92849