VARIABILITY AND GENETIC PARAMETERS FOR GRAIN YIELD AND ITS COMPONENTS AND KERNEL QUALITY ATTRIBURTES IN CMS BASED RICE HYBRIDS (ORYZA SATIVA L.)
The present investigation was under taken to study the extent of variability and genetic parameters with 16 parents and 48 hybrids for nine yield and its components and twenty five quality characters. The magnitude of difference between PCV and GCV was relatively low for all the traits, indicating less environmental influence. High GCV and PCV were recorded for harvest index, total number of productive tillers per plant and gelatinization temperature in parents and for total number of productive tillers per plant, number of grains per panicle, gelatinization temperature and amylose content in hybrids. High heritability coupled with high genetic advance as per cent of mean were recorded for gelatinization temperature, harvest index, total number of productive tillers per plant, number of grains per panicle, kernel length, kernel L/B ratio and grain yield per plant in case of parents and for gelatinization temperature, amylose content, total number of productive tillers per plant, number of grains per panicle and harvest index in case of hybrids indicating the additive gene effects in the genetic control of these traits and can be improved by simple selection in the present breeding material.
Estimates of genetic variability, heritability and genetic advance for grain yield and other yield attributing traits in rice (Oryza sativa L.)
Fifty two rice genotypes were evaluated in randomized block design for twelve metric traits to estimate the extent of genetic variability, heritability (broad sense) and genetic advance as per cent of mean. The analysis of variance revealed significant variability for all the characters studied. Among the 12 characters studied, high phenotypic and genotypic coefficients of variation were recorded for the traits viz. , panicle number per plant, weight of 1000 fully developed grains and grain yield plant -1 indicating that large amount of variation is present among the genotypes. High heritability coupled with high genetic advance as per cent of mean was recorded for time of heading (50% of plants with panicles), stem length (excluding panicle), panicle number per plant, weight of 1000 fully developed grains, decorticated grain width and grain yield plant -1 indicating that these traits were governed by additive gene effects and may be chosen as selection criteria for formulating breeding strategies in rice.
Studies On Quality Status of Indigenous Upland Rice (Oryza Sativa)
One hundred indigenous upland rice (Oryza sativa L.) germplasm collections grown in randomized block design with three replications were studied for their physical and thermochemical quality traits. The study revealed a relatively greater genetic variability for phosphorus and protein content, water uptake and volume expansion, than for other characters. The heritable component of variation was relatively high in volume expansion, test weight, water uptake and L/B ratio. The heritability coupled with genetic advance was high for water uptake, L/B ratio, test weight, and volume expansion. Protein content showed negative correlation with most characters studied, except grain breadth and phosphorus content. Most of the cooking quality traits had positive correlation among themselves but showed significant or nonsignificant negative association with protein. Study of qualitative traits like husk and kernel colour showed a wide range of variability. Interestingly, red kernel types had relatively higher protein content as compared to the white kernel types. A few promising lines have been identified for exploitation in further upland rice breeding programme.