\ Progressive Horticulture ',?) Vol. 43(2): 323-327, 2011 Genetic variability and correlation studies in Gladiolus hybrida L. under tarai condition of Uttarakhand Prabhat Kumar, RaviKumar Maurya, Binayak Chakraborty, Rakesh Mer and D. S. Mishra Department of Horticulture, Govind Ballabh Pant University of Agriculture and Technology, Pantnagar - 263 145, Uttarakhand Email: prabhatflori@gmail.com ABSTRACT Twenty nine genotypes of gladiolus were evaluated for fifteen different characters to ascertain the genetic variability and association among the characters during the year 2010-11 at G.B. Pant University of Agriculture and Technology, Pantnagar. The phenotypic coefficient of variation (PCV)was higher than genotypic coefficient of variation (GCV)for all the fifteen characters studied. The higher PCVand GCVestimates were found for number of daughter corm/mother corm and cormel production. High heritability with high genetic advance was observed for plant height, days to first floret show colour, weight of corm and cormel production. The correlation studies revealed that plant height exhibited highly significant and positive correlation with weight of corm, corm diameter, rachis length and number of leaf per plant. There exists a significant and positive relationship of number of leaf per plant with weight of corm, corm diameter and rachis length; spikes length with number of leaves per plant. Floret diameter also exhibited significant and positive correlation with marketable spike per corm and number of daughter corm per mother corm. However, non-significant and positive correlation was found in characters viz., plant height with durability of spike, marketable spike per corm and number of spike per corm; days to first floret show colour with spike length, rachis length and number of floret per spike; number of leaf per plant with cormel production; durability of spike with rachis length and corm diameter. KEY WORDS: Geneticvariability, Correlation,Gladiolus,Corm, Cut flower, Iridaceae INTRODUCTION Gladiolus (Gladiolus hybrida L.) is a bulbous plant, belongs to family Iridaceae. It is one of the leading cut- flower crops grown in our countries, known for its majestic spikes which contain attractive, elegant and delicate florets. A huge quantum of variability exists in this crop with respect to shape, growth habit, flowering behaviour, vase life, etc. Inspite of such variability, very few are having desirable characters in terms of yield and quality. 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 programmes. There are many varieties existing in gladiolus and every year there is an addition of new varieties. Therefore, to provide basic preliminary information to the plant breeders this correlation studies among important quantitative characters in gladiolus was undertaken. MATERIALS AND METHODS The present investigation was carried out at Model Floriculture Centre, Department of Horticulture, G. B. P. U. A. & T., Pantnagar in a randomized block design (RBD) with three replications. The experimental material for the present investigation was consisted of twenty nine genotypes of gladiolus. The investigation was conducted in open field at a spacing of 30 x 30 em. All recommended agronomic package and practices were followed to grow a successful crop. Observations were recorded on five selected plants from each genotype in each replication. Observations were recorded for date of sprouting (days), plant height (em), number of leaves/ plant, days to first floret show colour (days), number of floret/spike, floret diameter (em), spike length (em), durability of spike (days), rachis length (em), weight OJ corm (g) corm diameter (em), number of daughter corm/ mother corm, cormel production (g),total spike/corm and marketable spike/corm. Data were put to statistical analysis as per Panse and Sukhatme (1967). Genetic parameters like genotypic coefficient of variation (GCV) and phenotypic coefficient of variation (PCV) were estimated according to Burton and Vane (1953) and heritability as suggested by Weber and Moorthy (1952). Correlation analysis was carried out as per the formulae suggested by Fisher (1954). The significance of phenotypic and genotypic correlation coefficients was tested against 'r' value given in Fisher and Yate's table (1963) at (n-2) degree of freedom.