52 Genetic and correlation studies in tuberose for assessing the genetic variability A. GAIDHANI, S. BADGE, S. PATIL, M. INGOLE AND A. A. GANORKAR Horticulture Section, College of Agriculture Nagpur-440001, Maharashtra Received: 16-02-2016, Revised:07-05-2016, Accepted: 25-05-2016 ABSTRACT Ten genotypes of tuberose were evaluated for eighteen different parameters to ascertain the genetic variability and association among the characters during the year 2014-15 in the Horticulture Section, College of Agriculture, Nagpur. The experiment was conducted in three replications with a spacing of 20 x 20 cm. The results of the experiment revealed that Prajwal was superior in desirable direction for all the parameters studied. The phenotypic coefficient of variation (PCV) was higher than genotypic coefficient of variation (GCV) for all the thirteen characters studied. The higher GCV and PCV estimates were found for leaf area at 50 per cent flowering, weight of ten florets, spike yield plot -1 and moderate for height of plant, days to first harvesting, length of spike and vase life. High heritability and high genetic advance was observed for diameter of spike, length of rachis, weight of ten florets, number of florets spike -1 and spike yield plot -1 . The correlation studies revealed that genotypic correlation coefficient was higher than the phenotypic correlation coefficient for all the characters studied. Number of leaves clump -1 , leaf area at 50% flowering, diameter of spike, length of rachis, weight of ten florets, diameter of floret and number of florets spike -1 exhibited positive significant correlation with spike yield plot -1 . Genotype Prajwal was identified to be the best genotype which was followed by Arka Nirantara, and Hyderabad Single. Keywords: Correlation, genetic advance, heritability, tuberose, variability Tuberose (Polianthes tuberose) is one of the most important commercial bulbous ornamentals due to its potentiality for cut flower, trade, long vase life and essential oil industry, attractive long spikes, high cut flower yield and flowers are available round the year in tropical and subtropical climates (Vanlalruati et al. 2013). There is a tremendous scope for improvement especially with spike related traits through inter and intra specific hybridization programmes. A study on such traits will be essential for a successful breeding programme. In tuberose, like any other plant species, the phenotypic expression of a character is mainly governed by the genetic make-up of the plant, the environment in which it is grown and the interaction between the genotypes and the environment. Further, the genotype of a plant is controlled by additive gene effect (heritable), non-additive gene effect or dominance (non heritable) and epistasis (non-allelic interaction). Partitioning of phenotypic variability into its heritable and its non-heritabie components with suitable genetic parameters such as genotypic and phenotypic coefficient of variation, heritability and genetic advance is necessary (Radhakrishna et al., 2004; Vijaylaxmi et al., 2012 and Valalruati et al., 2013). A large quantum of variability exists in this crop with respect to growth habit, flowering behavior etc. Inspite of such variability, very few are having desirable characters in terms of yield and quality. The Email: shalinibadge@gmail.com study of interrelationship of various characters in the form of correlation is also important aspect in crop breeding. Knowledge of correlation studies helps the plant breeder to ascertain the real components of yield and provide an effective basis of selection. The characters contributing significantly to desirable traits can be significantly identified and can be used as alternate selection criteria in crop improvement programme. Considering the above aspects, the present study was undertaken to estimate the genetic variability and to find out the association among important quantitative characters in tuberose. MATERIALS AND METHODS This study was carried out at, Horticulture Section, College of Agriculture, Nagpur during the year 2014-15. Experimental material consisted of ten genotypes of tuberose viz., Prajwal, Shringar, Hyderabad single, NT-1, NT-2, Arka Nirantara, NT-3, NT-4, NT-5 and NT-6. The experiment was laid out in Randomized Block Design (RBD) with three replications. For planting of tuberose plot was prepared at the dimension of 0.8 x 1.6 m. Before planting, the bulbs were treated with copper oxychloride (0.1%) and the individual bulbs weighing 20-30 gm were selected for planting. The treated bulbs were planted at 5 cm depth at a spacing of 20 x 20 cm between the plant and row as per the standard recommendation on 21 th July, 2014. Uniform cultural Journal of Crop and Weed, 12(1):52-55(2016)