~ 821 ~ Journal of Entomology and Zoology Studies 2020; 8(4): 821-825 E-ISSN: 2320-7078 P-ISSN: 2349-6800 www.entomoljournal.com JEZS 2020; 8(4): 821-825 © 2020 JEZS Received: 02-05-2020 Accepted: 05-06-2020 Sreedhar Siddi Rice Breeding Scheme, Agricultural Research Station, Kunaram, Peddapalli, Professor Jayashankar Telangana Agricultural University, Peddapalli, Telangana, India Anil Deva Rice Breeding Scheme, Agricultural Research Station, Kunaram, Peddapalli, Professor Jayashankar Telangana Agricultural University, Peddapalli, Telangana, India Corresponding Author: Sreedhar Siddi Rice Breeding Scheme, Agricultural Research Station, Kunaram, Peddapalli, Professor Jayashankar Telangana Agricultural University, Peddapalli, Telangana, India Genetic variability studies for gall midge incidence, yield and its components in rice ( Oryza sativa L.) genotypes in Northern Telangana Sreedhar Siddi and Anil Deva Abstract The field experiment was conducted at Agricultural Research Station, Kunaram during the rainy season of 2017 to investigate genetic variability for gall midge incidence, yield and its components among thirty two genotypes. Considerable amount of genetic variability was observed among all the genotypes for all the traits under study. In general, phenotypic coefficients of variation (PCV) estimates were higher than genotypic coefficients of variation (GCV) estimates for all the studied characters. The GCV and PCV were high for gall midge incidence, number of grains per panicle, 1000-grain weight and grain yield. Additive gene action was predominant for gall midge incidence, number of grains per panicle, 1000-grain weight, grain yield, days to 50% flowering and plant height. Hence, combined results of coefficients of variation and heritability studies revealed that gall midge incidence, number of grains per panicle, 1000- grain weight and grain yield could be given due importance among the traits studied for further crop improvement. Keywords: coefficient of variation, galls, genetic advance, heritability, rice, yield 1. Introduction Rice (Oryza sativa L.) is the world’s most important crop and around three billion Asians use rice as an essential staple food that provides 35 to 60% of their daily calories [12] . Rice has been occupied larger area, accounts for nearly 5 lakh ha among the cereals during every rainy season in Northern region of Telangana State in India. Asian rice gall midge, Orseolia oryzae (Wood-Mason) is one of the important insect pests in Northern Telangana. In India, it is rated as third most important pest of rice in terms of spread, severity of damage and yield loss [7] . More recently, gall midge incidence has been increased in almost all the rice growing states of India which results in considerable yield losses as affected tillers bear no panicles or grains. In contrast, the maggots fail to induce gall formation on the resistance varieties and perish in 2-4 days after hatching. Breeding for gall midge resistant varieties has been important strategy with more yield and acceptable grain quality [14] . In a breeding programme, refinement of rice varieties with more yields along with gall midge resistance requires information on the nature and magnitude of variation in the available germplasm having wide variability, and degree of environmental influence on the expression of these traits. Knowledge concerning heritability is essential to the plant breeders to provide the information on the nature of progenies in the succeeding generations, to make appropriate selection and to assess the magnitude of genetic improvement. High genetic advance estimates along with high heritability values should be used for the effective selection of superior varieties [4] . Several workers studied the genetic variability for yield and its components in rice [11] . Information on the genetic variability of gall midge incidence, grain yield and its components is not available in the experimental material. Present study was hence undertaken to identify the most important traits for breeding programmes by exploring the genetic variation, heritability and genetic advance of yield, its components and gall midge incidence of 32 rice genotypes for development of high yielding, gall midge resistant genotypes for further improvement. 2. Materials and methods The seed of 32 rice genotypes was raised on nursery beds at Agricultural Research Station, Kunaram during the rainy season of the year, 2017 (Table 1).