Study of Hygienic practices of street food vendors in ... - Shiats.edu.in

The Allahabad Farmer Vol. LXVIII, January - 2013 No. 2(25.042%), moderate estimates of genotypic coefficient of variation (GCV) for numberof grains per spike (18.032%) followed by grain yield per plant (13.377%) and 1000grain weight (12.298), whereas low estimates of genotypic coefficient of variation (GCV)was observed for days to maturity (0.276%), plant height (3.230%) and days to flowering(4.777%). The higher magnitude of genotypic coefficient of variation (GCV) and phenotypiccoefficient of variation (PCV) were recorded in number of effective tillers per plant andnumber of grains per spike suggesting that sufficient variability present in the gene poolfor genetic improvement through selection for these traits. These findings are in agreementwith those of Dwivedi et al. (2002) and Sen and Toms (2007).Relatively low magnitudinal difference were observed for genotypic coefficient ofvariation (GCV) and phenotypic coefficient of variation (PCV) in relation to days tomaturity, plant height and days to flowering, indicating less environmental influence in theexpression of these attributes, while greater influence of the environment in the expressionof other traits. Thus, these values alone are not helpful in determining the heritable portionof variation.The proportion of genetic variability which is transmitted from parents to offspringis reflected by heritability (Lush, 1949). Highest heritability was observed for numberof grains per spike (94.4%) followed by 1000 grain weight (89.2%), plant height (84.1%),days to flowering (77.8%), number of effective tillers per plant (73.9%) and grain yieldper plant (73.6%) (Table 2). High estimates of heritability were also reported byPhadnawa et al. (2002) for test weigh, Nimbalker et al. (2002) for number of grainsper spike and Asif et al. (2004) for plant height.High genetic advance as per cent of mean was observed for number of number ofeffective tillers per plant (44.35%) followed by number of grains per spike (36.09%),1000 grain weight (23.93%) and grain yield per plant (23.65%), while days to maturity(0.10%), spike length (4.88%) and plant height (6.10%) showed low estimates of geneticadvance as per cent of mean.The estimates of heritability are more advantageous when expressed in terms ofgenetic advance. Johnson et al. (1955) suggested that without genetic advance theestimates of heritability will not be of practical value and emphasized the concurrent useof genetic advance along with heritability. Based on this consideration, high heritabilityaccompanied with high genetic advance was registered for number of grains per spike,number of effective tillers per plant, 1000 grain weight and grain yield per plant. Thisindicates that to heritability is most likely due to additive gene effects and thus selection77