Studies on Genetic Variability for Yield, Yield Components and Resistance to Kalahasti Malady in Groundnut (Arachis Hypogaea L.)..

Twenty one crosses of groundnut derived from 7×7 diallel set without reciprocals were evaluated during rabi 2010-11 for variability, heritability and genetic advance. Analysis of variance for thirteen traits revealed highly significant differences among the F2 populations tested. The estimates of GCV and PCV were high for number of secondary branches per plant, kernel yield per Plant (g), total phenols content (mg/g), pod yield per plant (g), number of kernels per plant and harvest index. High heritability coupled with high genetic advance as percent of mean for traits viz., days to 50% flowering, total phenols, number of secondary branches per plant, harvest index, kernel yield per plant and number of kernels per plant indicate that these are predominantly influenced by additive gene action and the possibility of phenotypic selection in early generations. High heritability coupled with moderate genetic advance as percent of mean for number of primary branches per plant and moderate heritability coupled with moderate genetic advance as per cent of mean for 100-kernel weight indicate the role of both additive and non additive gene action with preponderance of additive genetic variance and selection would be effective to some extent.

Correlation and Path Coefficient Analysis in Groundnut (Arachis Hypogaea L.).

Sixty six genotypes of groundnut were used to study the correlation and path analysis for yield and yield contributing characters. Correlation studies revealed that kernel yield was significantly and positively associated with pod yield per plant, number of mature pods per plant, shelling percentage, harvest index, sound mature kernel percentage, specific leaf weight at 60 DAS, protein content and oil content. Path coefficient analysis indicated that pod yield per plant and shelling percentage had high positive direct effect on kernel yield signifying the importance of these traits in the improvement of seed yield.

Genetic Variability Studies in Different Advanced Breeding Genotypes of Spanish Bunch Groundnut (Arachis Hypogeae).

Significant differences were observed among thirty seven genotypes for all the traits studied. High genetic coefficient of variation was recorded for days to 50 per cent flowering. High heritability of 97.33 per cent was observed for pod yield per plant. High heritability and high genetic advance as percent of mean was recorded for plant height, haulms yield per plant, pod yield per plant and kernel yield per plant. These characters could be further improved through single plant selection. Moderate heritability and high Genetic advance as per cent of mean was observed for number of primary branches per plant, number of secondary branches per plant, number of mature pods per plant and 100 pod weight indicating the importance of both additive and non additive gene action in the inheritance of these characters.

Inheritance studies of plant height, pod and seed attributes in F2 genertion of certain groundnut (arachis hypogaea l.) crosses.

Inheritance of plant height, pod length, pod width, seed length and seed width was studied in a set of crosses grown during rabi 2007-08. F2 phenotypic data for plant height was a good fit to a phenotypic ratio of 1:4:6:4:1 and 1:2:1 respectively in two crosses studied indicating the involvement of more than two genes. Segregation of pod length in F2 generation of the cross ICGV 00350 x K 1340, was a good fit to a phenotypic ratio of 45 medium short : 19 long pods while in the cross ICGV 00350 x TG 37A segregation of pod length was a good fit to a phenotypic ratio of 1 long : 2 medium : 1 short pod length. Segregation of pod width in the crosses ICGV 00350 x K 1340 and ICGV 00350 x TG 37A presented a good fit to a phenotypic ratio of 3 high width: 1 medium width pods, while in the cross ICGV 00350 x Jyothi, F2 segregation data was a good fit to a phenotypic ratio of 1 high width: 2 medium width: 1 low width pods. F2 segregation of seed length in the cross ICGV 00350 x K 1340 was a good fit to a phenotypic ratio of 13 long medium: 3 short. Segregation of seed width in F2 generation of the crosses K 1340 x TCGS 888 and K 1340 x Narayani was a good fit to a phenotypic ratio of 15 medium low : 1 high width and 3 low : 1 medium width seeds.

Genetic variability studies for yield attributes and resistance to foliar diseases in groundnut (arachis hypogaea l.).

Twenty eight F2 populations (crossed in an 8 × 8 diallel fashion without reciprocals) of groundnut were evaluated in randomized block design with three replications for variability, heritability and genetic advance during rabi 2009-10. Observations on sixteen characters were recorded. Analysis of variance revealed highly significant differences among the genotypes for all the characters except number of mature pods per plant and pod yield per plant. High GCV accompanied by high heritability and high GAM were obtained for percentage of leaves affected by foliar diseases per plant and number of immature pods per plant indicating predominant role of additive gene action and amenability for phenotypic selection in early generations. For late leaf spot and rust severities and harvest index moderate GCV and high heritability and GAM was observed. Moderate GCV, heritability and GAM were registered for plant height at harvest, number of primary branches per plant, number of leaves per plant at harvest, number of mature pods per plant, kernel weight per plant indicating that additive and non-additive gene actions have a role in their inheritance and phenotypic selection would be effective to some extent. For days to 50% flowering and days to maturity, GCV was low, heritability was high and GAM was low. For sound mature kernel percentage and shelling out-turn all the genetic parameters were low indicating larger role of non-additive gene action and selection would be effective in later segregating generations.

Variability, heritability and genetic advances in F2 generation of 15 crosses involving bold-seeded genotypes in groundnut (arachis hypogaea l.).

Significant differences were observed among F2 population of fifteen single crosses and parents for all characters. Plant height, number of primary branches, number of secondary branches, pod yield/plant showed higher values of Genotypic Co-efficient of Variation (GCV) and Phenotypic Coefficient of Variation (PCV), heritability (broad sense) and Genetic Advance as per cent of Mean (GAM). The role of additive gene action seems to be significant in the inheritance of these traits. Thus phenotypic selection is early generations would help to make improvement in these characters. Number of mature pods and number of immature pods showed low to moderate values of GCV, PCV, heritability (broad sense) and GAM. The role of non-additive gene action seems to be significant in the inheritance of these traits. In these characters, early generation selection followed by biparental matings and selection in later generations would help to isolate lines with improvement in these traits. Shelling out-turn and sound mature kernel percentage were found to be governed by both additive and non-additive gene action.