Genetic variability and correlation studies were conducted on 110 genotypes of rice. Estimates of genotypic variance, phenotypic variance, genotypic coefficient of variation, phenotypic coefficient of variation, heritability in broad sense, genetic advance and association for grain yield with floral, quantitative and quality characters were computed. The characters, viz., stigma exsertion percent, anther length, outcrossing rate, number of grains per panicle, single plant yield, volume expansion ratio, gel consistency, gelatinization temperature and amylose content possessing high GCV, heritability and genetic advance ,were effectively used in selection. The single plant yield had highly significant and positive association with the number of productive tillers per plant, panicle length, number of secondary branches per panicle, 100 grain weight and number of grains per panicle.

Rice occupies a predominant position among major food grains, fulfilling about 60% of dietary requirement, 20% of calorie and 14% of protein requirement of the world population. The study of genetic variability is a basic requirement in any crop improvement program for deciding the efficiency of selection. The extent of genetic variability existing in a crop is of great importance, since greater the diversity wider the scope for selection. Genetic improvement for quantitative traits can be achieved through a clear understanding of the nature and amount of variability present in the genetic stocks and the extent to which the desirable traits are heritable. The analysis of genetic variation both within and among elite breeding materials is of fundamental interest to plant breeders. It contributes to monitoring germplasm and can also be used to predict potential genetic gains. The studies on correlation of characters indicate the intensity and direction of character association in a crop. The interrelationship of component characters of yield provided the information about the consequences of selection for simultaneous improvement of desirable characters under selection. Yield being complex polygenic character is the ultimate expression of many components. The present investigation was carried out to assess the magnitude of genetic variability and correlation of collected rice genotypes between morphological and grain quality traits.

The study was conducted on 110 rice genotypes selected from the germplasm materials received from Barwale Foundation, Hyderabad, Directorate of Rice Research, Hyderabad and different research stations of Tamil Nadu Agricultural University, which were raised in Randomized Block Design (RBD) during September 2007 for the analysis of genetic variability. The observations were recorded on seven floral, eight quantitative and 16 qualitative characters as per the Standard Evaluation System (SES, 1996) descriptors suggested by IRRI. Each genotype was raised in two rows with two replications with 2.4 m row length. A spacing of 20 ´ 20 cm was adopted. The recommended package of practices was followed. Genetic parameters like variability, GCV, PCV, heritability and genetic advance were computed according to the method suggested by Lush (1940) and Johnson et al. (1955). The association between yield and component characters and among themselves was computed based on genotypic and phenotypic correlation coefficients (Goulden, 1952).

Genetics & Evolution Journal, Genetic Variability, Grain Quality Traits, Genetic Parameters, Standard Evaluation System, Crop Improvement Program, Rice Genotypes, Breeding Programs, Linear Elongation Ratio, Gelatinization Temperature, Volume Expansion Ratio.