STUDY ON GENETIC VARIABILITY AND HERITABILITY IN Ocimum spp. M. Shehbaz Khan, D.K. Bahuguna, Rajeev Kumar¹, Nitin Kumar¹ and Ishrat Ahmad Lone Department of Seed Science and Technology, Ch.Charan Singh University, Meerut. 1 Department of Ag. Botany, CSSS (P.G.) College Machhra, Meerut. ABSTRACT: A field experiment was conducted during kharif season of 2008 to study the variability of 25 genotypes of Ocimum spp. for 11 traits. The estimate of maximum range and coefficient of variability were noted for six different characters including plant height, leaf length, no. of inflorescence/plant, length of inflorescence, days to maturity and fresh herb yield /plant. The highest estimates of heritability in broad sense were observed for plant height (99.70 %) followed by length of inflorescence /plant (98.80 %), fresh herb yield per plant (98.60%), no. of inflorescence/plant (98.40%), days to maturity (92.60%) and leaf width (91.50%). The highest value of genetic advance was obtained for fresh herbage yield per plant (1018.02) followed by dry herb yield per plant (394.31), no of inflorescence/plant (43.76) and plant height (39.13). Highest values of genotypic and phenotypic covariance indicated wide range of variability and high heritability associated with higher values of relative genetic advance. Keywords : Genetic variability, heritability, genetic advance, Ocimum spp. The genus Ocimum L. (Lamiaceae), collectively called basil comprises 30-160 annual and perennial herbs and shrubs native to tropical and subtropical regions of Asia, Africa and Central and South America (Paton, 12). Sweet basil, Ocimum basillicum L., is well known for its numerous economical, medicinal and aromatic values (Simon et al., 16) and Morales and Simon, 10). Medicinally, it is useful in a variety of human and animal diseases treatment such malaria, colic, vomiting, common cold, cough and skin diseases (Bhattacharjee, 4). The importance of basil is increasing and has promising future in Egypt, especially, when cultivated in new reclaimed soil under organic agriculture conditions (Abd-El Raouf, 1; and Aboud et al., 2). Genetic improvement in aromatic plants for quantitative characters is helpful for determination of yield components to improve oil yield through selection of genotypes from population (Kazmferezak et al., 8; and Seidkr-Ozykowska et al., 14). Genetic parameters estimating (PCV, GCV, h 2 b and GA) are important to determine genetic variability among selected genotypes of different species of basil (De Masi et al., 6; Nurzynska-Wierdak, 11). The objectives of this study were to determine the variation and genetic interrelationships among herb yield components of basil using genetic parameters. MA TERIALS AND METHODS The present study was carried out during two successive growth seasons of 2008 at the farm of Department of Seed Science and Technology, C.C. S. University, Meerut. 25 Ocimum genotypes seeds were selected and sown in bed on 25 March. 35 days old seedlings were transplanted into field on 1st May 2008. All plants were fed by organic manure without any chemical nutrient addition. The plants were harvested 2 times (Cuts) during July and September in both seasons. Data recorded on the 25 genotypes from each replicate in both cuts for 11 characters included: plant height (cm), number of primary branches /plant, number of secondary branches / plant, days to flowering, leaf length (cm), leaf width (cm), number of inflorescence/plant, length of inflorescence (cm), days to maturity, fresh herb yield / plant (g) and dry herb yield / plant (g). A complete randomized block design with three replications was used in the experiment. The general statistical procedures was practiced according to Steel and Torrie (17). Analysis of variance (ANOVA) and broad sense heritability (h 2 ) were generally assigned for the data HortFlora Research Spectrum, 1(2): 168-171 (2012) ISSN : 2250-2823 Received : 21.3.2012 Accepted : 12.4.2012