International Journal of Plant Sciences

J. Shanthala ¹, M. R. Gururaja Rao ¹, E. Gangappa ¹, P. Venkataravana ¹

Affiliations
1 Department of Genetic and Plant Breeding, College of Agriculture, University of Agricultural Sciences, G.K.V.K., Bengaluru, Karataka, IN

Abstract

An experiment to study the effectiveness of -rays and ethyl methane sulphonate induced mutagenesis in bringing about shift in mean and creation of genetic variability for pod yield and its attributes in two varieties of groundnut viz., GPBD-4 and CTMG-1 and their _F2 and F₂M₂ generations was carried out during 2006-08, at Agricultural Research Station, Chintamani, UAS (B). The LD₅₀ dose was fixed at 20 kR for gamma ray irradiation and at 0.5 per cent for ethyl methane sulphonatee (EMS). The two varieties exhibited differential response to different mutagens. In general, the overall shifts in the mean of F₂M₂ population was maximum in the desirable directions compared to any other populations followed by 20 kR irradiated M₂ population of CTMG-1. The F₂M₂ population manifested maximum heritability (96.44%) and genetic advance as per cent of mean (76.24%) and among the mutagen treated M₂ populations, maximum heritability (81.35 %) and genetic advance as per cent of mean (41.50%) was recorded in 20 kR irradiated populations of GPBD-4 for pod yield (g/plant). The mutagenic treatment with 20 kR irradiated and 0.5 per cent EMS treated GPBD-4 and CTMG-1 populations and F₂M₂ population have resulted in creation of higher genetic variations and hence serve as an excellent source material for variety development representing a more efficient source of genetic variability than gene pools conserved by nature.

Keywords

Induced Mutagenesis, Shifts in Mean, Genetic Variability, F₂m₂ Population

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K. V. Vijaya Kumar ¹, K. T. Venkatesha ¹, M. Asif ¹, E. Gangappa ¹, M. Pitchai Muthu ²

Affiliations
1 Department of Genetics and Plant Breeding, University of Agricultural Sciences, G.K.V.K., Bengaluru, Karnataka, IN
2 Division of Vegetable Crops, Indian Institute of Horticultural Research, Hesaraghatta, Bengaluru, Karnataka, IN

Abstract

Using Mahalonobis D² statistic and Tocher method, 166 germplasm lines were grouped into 18 divergent clusters. Clustering pattern was not associated with geographical region of genotypes. Hence, Geographical separation may not be referred as index of genetic diversity. Yield per plant, Mean inter-node s length and nodes per plant contributed largely for total divergence, revealing ample scope for improvement of these traits. Maximum number of genotypes were congregated in cluster XVIII followed by cluster I. the highest inter cluster distance between cluster I and cluster XVIII emphasized the possibilities of getting high heterotic F1 hybrids as well as transgressive segregants in advanced generations for different traits , when hybridization is carried out involving genotypes between these two divergent clusters.

Keywords

Intra And Inter Clusters Distances, Intra And Inter Clusters Divergence And per Cent Contribution

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Mahesh Meena ¹, E. Gangappa ¹, K. Mallikarjun ¹, T. Basavaraja ¹, M. Asif ¹, K. T. Venkatesha ², N. M. Basavaprabhu ², K. V. Vijayakumar ²

Affiliations
1 Department of Genetics and Plant Breeding, University of Agricultural Sciences, G.K.V.K., Bengaluru, Karnataka, IN
2 Department of Genetics and Plant Breeding, G.K.V.K., University of Agricultural Sciences, Bengaluru, Karnataka, IN

Abstract

Studies were conducted on genetic variability for ten quantitative characters in F2 generation of three crosses in okra. The genotypic and phenotypic co-efficients of variations were moderate to high for all the characters except ridges per plant with reference to F₂ generation of the crosses C-II and C-III; whereas the F2 of C-I showed moderate to high PCV and GCV for all the traits except fruit diameter and fruits per plant High broad sense heritability coupled with high genetic advance as per cent of mean was recorded for fruit length and primary branches in C-II and C-III and for fruit length followed by nodes per plant in C-I which indicated lower environmental influence on these traits and the prevalence of additive genes. Simple and early selection schemes would be effective for the improvement of these traits.

Keywords

Okra, Genetic Variability, Genetic Advance, Heritability

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K. V. Vijaya Kumar ¹, K. T. Venkatesha ², M. Asif ¹, E. Gangappa ¹, M. Pitchaimuthu ³

Affiliations
1 Genetics and Plant Breeding, University of Agricultural Sciences, G.K.V.K., Bengaluru, Karnataka, IN
2 Department of Genetics and Plant Breeding, University of Agricultural Sciences, G.K.V.K., Bengaluru, Karnataka, IN
3 Division of Vegetable Crops, Indian Institute of Horticultural Research, Bengaluru, Karnataka, IN

Abstract

The analysis of variance revealed significant differences among the okra collections for all the traits. The estimates on variability parameters indicated considerable range of variation in the germplasm for all the characters studied. Environmental influence was meagre on expression of characters as evident by narrow gap between genotypic and phenotypic co-efficient of variation. The genotypic and phenotypic co-efficients of variations were high for all the characters except days to 50 per cent of flowering and ridges per fruit. A high range of variation, genotypic co-efficient of variation, heritability and genetic advance on per cent mean for plant height, branches per plant, nodes per plants and fruit yield per plant was recorded. This indicated broad genetic base, less environmental influence and these traits are under control of additive genes, simple and early selection schemes would be effective for improvement of these traits. Despite high heritability, the mean of genetic advance was low for days to 50 per cent flowering indicating low variability for this trait.

Keywords

Genetic Variability, Okra, Germplasm

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