Electronic Journal of Plant Breeding, 6(3): 855-860 (Sep 2015) ISSN 0975-928X http://ejplantbreeding.com 855 Research Note Genetic analysis and correlations in mid early genotypes of rice (Oryza sativa L.) under irrigated condition Sindhumole, P*., Veena, V. and Beena, R. Division of Plant Breeding and Genetics, Regional Agricultural Research Station, Pattambi – 679 306, Palakkad district, Kerala *E-mail: sindhumolp@gmai.com (Received:23 Feb 2015; Accepted:30 Mar 2015) Abstract Sixty four mid early rice genotypes of diverse origin, with three check varieties viz., IR 64 (National), MTU 1010 (Southern Regional) and Jyothi (Local), were evaluated under irrigated wet land conditions. Analysis of variance indicated highly significant variation for all the traits indicating the presence of genetic diversity among these genotypes. Genotypic and phenotypic coefficients of variation (GCV and PCV), heritability and genetic advance (% of mean) were high for all the characters. The highest heritability was observed for plant height (96.71) followed by panicle length (90.57). However, grain yield exhibited the lowest heritability (54.74) among all the traits. Positive association existed among all the traits. Grain yield was highly associated with plant height and panicle length. The top yielding genotypes identified in the study were MTU 1155, UPRI 2012-18, HKR 08-62 and RNR 10294. Keywords Rice, genetic variability, heritability, correlation Rice (Oryza sativa L.) is an important staple food that provides 66-70 % of calorie requirement of the consumers. To ensure food security in rice consuming countries of the world, rice production must be enhanced to an extent of 50 per cent by 2025. In Indian agriculture, rice plays a pivotal role, being the livelihood for 150 million rural households and accounting for 43% of national food grain production (DRR, 2005). However, yield level of this crop has reached a plateau and improving its productivity and quality traits has become crucial (Vanaja and Babu, 2006). To accomplish this, crop improvement programmes should aim at broadening the genetic base of breeding stock. Success in crop improvement generally depends on the magnitude of genetic variability and the extent to which the desirable characters are heritable. Estimation of genetic variability present in the germplasm of a crop is a pre-requisite for making any effective breeding program. However, variability studies and association grain quality characters of high yielding rice varieties of specific eco-geographical origin are limited. Hence, the present study was undertaken to evaluate the extent of variability, genetic parameters and correlations in high yielding diverse genotypes for important yield parameters. Sixty four mid early rice genotypes of diverse origin were evaluated during Kharif 2012 under irrigated wet land conditions at Regional Agricultural Research Station, Pattambi. Three genotypes viz., IR 64 (National), MTU 1010 (Southern Regional) and Jyothi (Local) were included as check varieties. The experiment was laid out in a completely randomised block design with two replications. Each plot had eleven rows with sixteen hills per row having a spacing of 20 cm between rows and 15 cm between hills. Cultural and Management practices were followed as per KAU Package of Practices Recommendations. At maturity, five plants were randomly selected from each genotype in each replication for recording observations on seven biometric traits viz., days to 50% flowering, plant height, tillers/plant, panicles/hill, panicles/m 2 , panicle length (cm), and grain yield (t/ha). In addition, grain type of each genotype was also recorded. ANOVA was performed for all the biometric traits. Genetic parameters viz., genotypic coefficient of variation (GCV), phenotypic coefficient of variation (PCV), heritability (broad sense), genetic advance (% of mean) and correlation coefficients among the characters were estimated (Singh and Choudhary, 1985). Genetic variability: Per se performance of 64 rice genotypes for traits evaluated are furnished in Table 1. The results revealed wide variation for days to 50% flowering (71-113.5), plant height (83.8-137 cm), tillers/plant (3.7-11.5), panicles/hill (3.7-11.1), panicles/m 2 (123-370), panicle length (19.1 to 28.3 cm) and grain yield/ha (2.1-7.3 tons). ANOVA indicated highly significant variation for all the traits studied thereby indicating the presence of genetic diversity among these genotypes (Table 2). These results are in agreement with previous studies by Anbanandan et al. (2009) and