Genetic Studies for Fodder Yield and Yield Components in Sorghum (Sorghum Bicolor L. Moench)

Abstract

The present investigation entitled “Genetic studies for fodder yield and yield components in sorghum (Sorghum bicolor L. Moench)” was undertaken to collect information on genetic parameters for yield and its components from a ten parents diallel mating design in linseed at Crop Research Centre, Sardar Vallabhbhai Patel University of Agriculture & Technology, Meerut (U.P.) during kharif 2020 and 2021. The experimental material was comprised of 10 diverse parents and their 45 F1s excluding reciprocals of a diallel cross. All genotypes were evaluated in a complete randomized block design with three replications. The data were recorded on ten characters i.e., days to 50% flowering, plant height, leaf breadth, leaf length, stem girth, leaves per plant, leaf area, leaf stem ratio, total soluble solids and green fodder yield. The data were recorded subjected to various statistical analyses. Analysis of variance for parents and crosses showed highly differed significantly for all the ten characters viz., days to 50% flowering, plant height, leaf breadth, leaf length, stem girth, leaves per plant, leaf area, leaf stem ratio, total soluble solids and green fodder yield. Parents vs crosses were found highly significant for all the traits, indicated that wide genotypic differences among the parental lines and F 1’s hybrids. High heritability coupled with high genetic advance as percent of mean was observed for the characters namely plant height, stem girth, leaf stem ratio and green fodder yield per plant, indicating the influence of additive gene action and, consequently, a possibility of improving these attributes through selection. Green fodder yield exhibited significant stable and positive correlation with leaf area, leaves per plant and plant height at genotypic and phenotypic level, suggesting that selection of these characters may be practiced for gain higher fodder yield in forage sorghum. Leaf stem ratio displayed high order of direct effect on green fodder yield per plant followed by leaves per plant, leaf area, stem girth and total soluble solids at phenotypic and genotypic level, indicated that these characters may be selected directly for improving the fodder yield in forage sorghum. Estimates of additive genetic variance D was noted positive significant for all the characters namely, days to 50% flowering, plant height, leaf breadth, leaf length, stem girth, leaves per plant, leaf area, leaf stem ratio, total soluble solids and green fodder yield per p lant, indicated predominance of additive gene action in the inheritance of these attributes. Dominance components H1 and H2 recorded highly significant and positive for all the characters in F1 generation. The estimates of H1 values were higher than the values of H2 for all the attributes, indicated that unequal allelic frequencies at relevant loci in the population. Value of F was observed highly significant and positive for days to 50% flowering, plant height, leaf breadth, leaf length, stem girth, leaves per plant, leaf area, leaf stem ratio, total soluble solids and green fodder yield in F1 generation, which indicates the excess of dominant and positive allele in the parents for governing these attributes. Estimates for degree of dominance (H1/D)½ exhibited to be more than unity in F1 generation for all the ten characters, suggested that the existence of over dominance for these attributes. Ratio of gene with positive and negative effects in the parents H2/4H1 was found less than unity theoretical value (0.25) for days to 50% flowering, leaf breadth, leaf length, stem girth, leaf area, leaf stem ratio and total soluble solids in the F1 generation, which indicated that dissimilar distribution positive and negative alleles. Proportion [(4DH1)½+F/(4DH1)½-F)] indicates the ratio of dominant and recessive alleles among the parents. It was recorded more than unity for days to 50% flowering, plant height, leaf breadth, leaf length, stem girth, leaves per plant, leaf area, leaf stem ratio, total soluble solids and green fodder yield, which indicated accumulation of dominant alleles in the parents for these traits. Ratio h2/H2 is an important measure of the group (s) of the genes controlling the character and exhibiting dominance. The value of this ratio was found more than unity for plant height, leaves per plant and leaf stem ratio in F1 generation, indicated that more than one major gene groups are responsible for governing these characters and rest of the characters observed the prop ortion of h2/H2 less than one unity, indicating the presence of at least one major gene or gene group is controlling these traits. The mean degree of dominance (σ2g/σ2s)1/2 was estimated greater than unity for days to days to 50% flowering, stem girth, leaf area, leaf stem ratio and green fodder yield, indicated the involvement of over dominance for this trait, whereas it was less than unity for plant height, leaf breadth, leaf length, leaves per plant and total soluble solids, indicating that the involvement of partial dominance for these attributes. On the basis of overall gca effects and per se performance among the lines, CSV-17 was identified as good general combiners for maximum 8 traits including green fodder yield and UP Chari-2 for 7 attributes, suggested that these parents may be used in the hybridization programme aimed devolvement of superior genotypes in forage sorghum. On the basis of overall results and fodder yield performance the crosses viz., Pant Chari-8 x Pant Chari-7, HC-136 x Pusa Chari-6, CSV-17 x Pusa Chari-6 and CSV-15 x Pant Chari-7 were identified as best specific combiners for maximum attributes including green fodder yield for 8 to 9 other contributing traits, which may be utilized for obtaining transgressive segregates in the next generation. On the basis of overall findings and per se performance the manifestation of high degree of heterosis over better and mid parent in certain cross combinations i.e., Pusa Chari-23 x Pant Chari-8, UP Chari-2 x HC-136, UP Chari-2 x Pusa Chari-23, UP Chari-2 x Pusa Chari-6 and CSV-17 x Pusa Chari- 6, suggested that great possibility to produce higher fodder yield varieties.