Please cite this article in press as: Patel, R.P., et al., Study of genetic variability pattern and their possibility of exploitation in Ocimum germplasm. Ind. Crops Prod. (2015), http://dx.doi.org/10.1016/j.indcrop.2014.12.043 ARTICLE IN PRESS G Model INDCRO 7726 119–122 Industrial Crops and Products xxx (2015) xxx–xxx Contents lists available at ScienceDirect Industrial Crops and Products jo ur nal home p age: www.elsevier.com/locate/indcrop Study of genetic variability pattern and their possibility of exploitation in Ocimum germplasm R.P. Patel a , R.R. Kumar b , R. Singh a , R.R. Singh c , B.R.R. Rao d , V.R. Singh a , Pankhuri Gupta a , Rashmi Lahri a , R.K. Lal a,∗ a CSIR – Central Institute of Medicinal and Aromatic Plants, P.O. CIMAP, Lucknow, U.P. 226015, India b CSIR – Central Food Technological Research Institute, Mysore 570020, India c University of Lucknow, Lucknow, U.P. 226007, India d CSIR-CIMAP, Research Center Hyderabad 500039, India a r t i c l e i n f o Article history: Received 1 June 2014 Received in revised form 16 December 2014 Accepted 19 December 2014 Available online xxx Keywords: Cluster Genetic diversity Mahalanobis D 2 analysis a b s t r a c t The present study was designed to evaluate genetic diversity among fifteen accessions of five Ocimum species. Mean data from three locations of two consecutive years (2007–2009) was evaluated in the study. Highly significant ANOVA results indicated the presence of a high amount of genetic variability which was also confirmed by the wide range of D 2 -values. The observations defined genotypes into six clusters. The intra-cluster divergence was maximum within cluster-I (18.30) while, the inter-cluster divergence was highest between clusters-II and VI (76.01). The highest contribution toward total divergence was observed for leaf width (18.30%) followed by oil yield g/plot (14.41%) and leaf area (11.37%), while, leaf stem ratio (5.74%) and plant height (5.66%) contributed lowest. Clusters III and IV recorded for highest herb and essential oil yield, respectively. The highly divergent accessions namely, OCA-12, OCG-13, OCG- 14, OCB-7 and OCB-8 can be exploited for the development of high oil yielding Ocimum cultivars/varieties. © 2014 Elsevier B.V. All rights reserved. 1. Introduction The genus Ocimum (family: Lamiaceae) is cultivated around the world (Marotti et al., 1996) for culinary and medicinal purposes (Holm, 1999), used as a treatment of cold and cough, mouth- wash, diuretic, carminative, appetite stimulants, astringent and tonic agents (Morales and Simon, 1996; Grayer et al., 1996). It is also an important source of aromatic oil used as perfume and cologne in cosmetics and pharmaceutical industries, and widely acclaimed for its biologically active constituents that are insecticidal (Bowers and Nishida, 1980; Chatterjee et al., 1982), antimicrobial (Suppakul et al., 2003; Bozin et al., 2000; Harisaranraj et al., 2008) and antiox- idant (Carovic-Stanko et al., 2010). The genus Ocimum exhibits large morphological groups, comprising approximately 30 to 160 species (Paton, 1992; Pushpangadan and Bradu, 1995) owing to the ease of cross pollina- tion leading to a large number of sub-species, varieties and forms. The genus exists as morphotypes-differing in morphology (Prakash, ∗ Corresponding author. Tel.: +91 0522 2718523; fax: +91 0522 2718639. E-mail address: rajkishorilal@gmail.com (R.K. Lal). 1990; Marotti et al., 1996), chemotypes – differing in essential oil composition (Vieira et al., 2006) and genotypes-differing at the DNA level (Labra et al., 2004). The genetic improvement of the crop depends mostly on the nature and relative magnitude of genetic variance components concerned with yield and yield related attributes. Although, several models are available for the estimation of genetic diversity in Ocimum but by using of the sophisticated biometrical model like D 2 -statistics and canonical analysis described by Mahalanobis (1936) and Rao (1952) has been on a very limited scales in India and abroad. This biometrical approach is applied first time in the present set of Ocimum The findings of this study will be certainly add in the literature. The genetic improvement of any crop including Ocimum depends upon the careful selection of the genetic material to be utilized in breeding program. Among other factors, that assess- ment depends on the characteristics to be enhanced, the category of inheritance of the traits, and the source of available germplasm collections (Blank et al., 2012; Lal, 2014). Identification and char- acterization of desirable parental combinations provide the basis for selection in the follow-up breeding process for exploitation of heterosis. Parents with high genetic diversity, when crossed, have a propensity to demonstrate higher heterosis, than those with low genetic divergence (Hayes, 1952). http://dx.doi.org/10.1016/j.indcrop.2014.12.043 0926-6690/© 2014 Elsevier B.V. All rights reserved. 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50 51 52 53 54 55 56 57 58 59 60 61 62 63