Genetic Analysis over Environments for Quantitative Traits in Early Rice Studied through On-farm Trial

摘要

An on-farm trial was conducted at farmer's fields during kharif 2008 and 2009 with 11 early rice cultivars and one locally adopted variety as control in order to study the genetic variability and to identify the most superior high yielding cultivar for adoption in up and mid land ecosystem of Gopalganj district of Bihar. Eleven yield and yield attributing traits, namely, days to 50% flowering, number of productive tillers per hill, plant height, number of total grains per panicle, number of fertile grains per panicle, panicle length, harvest index, number of spikelets per panicle, 1000-grain weight, grain yield per plant and grain yield per ha were studied. The mean sum of squares due to genotypes was found to be highly significant in individual as well as in pooled analysis indicating that the cultivars possessed inherent genetic differences with respect to all the characters. High degree of phenotypic and genotypic coefficients of variation was recorded for grain yield per plant, spikelets per panicle, productive tillers per hill and days to 50% flowering consistently in both the years. The narrow magnitude of differences between these two estimates during both the seasons for days to 50% flowering, plant height and 1000-grain weight suggested a limited role of environmental variation on their expression. These traits also showed consistently high heritability coupled with high genetic advance as per cent of mean, whereas harvest index exhibited their low estimates. Other traits showed moderate tohigh heritability and high genetic advance as per cent of mean. Three varieties, namely, Rajendra Bhagwati (51.10 q), Prabhat (49.90 q) and Gautam (47.70 q) showed significant and highest grain yield per ha as compared to local variety IR-36 (37.50 q) in pooled analysis. These cultivars matured 10-20 days earlier than the control. It was observed that the cultivars performed high yield also exhibited high mean values for most of the yield attributing traits. These varieties are recommended to popularize for adoption in the district for higher yield, better profitability and early harvest of the crop.