Genetic Studies in Temperate Maize (Zea mays L.) Involving an Indigenously Identified Cytosterile Source

摘要

The present investigation was undertaken to generate information on variability and correlation coefficient in maize involving indigenously identified cytosterile source. Analysis was carried out in two crosses viz., 15C (A) x 1-318 (R) and 1-401 (A)x 1-318 (R) for all six generations with Pp P2 and F: having 30 plants each and F,(300 plants), BC, (180 plants) and BC2 (180 plants) for yield, yield attributing traits and protein content. Variances arising due to differences among various generationsof both crosses were highly significant for almost all characters. Components of phenotypic variability estimated for all the traits indicated that wide range of variability existed for the traits under study suggesting possibility of isolating superiorheterotic cross combinations. The estimates of phenotypic variance were higher than the corresponding estimates of genotypes variance for all the traits probably due to influence of environment in expression of these traits.Heritability broad sense (b.s.) values in general were higher than heritability narrow sense (n.s.) except low values observed for days to 75% husk browning, stalk lodging and root lodging suggesting a large participation of genetic effects on phenotypicexpression of the traits and that selection for these traits would be expected to be highly efficient. For protein content significant differences between generations suggested sufficient variability in the genetic material for the trait. High heritability (b.s.) in cross 1-401 (A) x 1-318 (R) as compared to cross I-15C (A) x 1-318 (R) coupled with very low GCV values for both the crosses was revealed. The estimates of genotypic correlation coefficient between grain protein, yield and yield component traits were mostly found to be higher in magnitude though similar in direction than their estimates at phenotypic level but non-significant association was found between protein, yield and yield contributing traits although significant and positive correlations were exhibited by kernel rows ear1, kernels row1, 250 grain weight, dry ear weight and shelling percentage with grain yield plant"1 in both the crosses. The higher magnitude of genotypic coefficients in the present study will be beneficial in selection of genetically controlled characters.