Study of Genotype X Environment Intraction in Asiatic Cotton Gossypium

Cotton is known as â€Å"White Gold†. Gossypium arboreum belongs to family Malvaecae with diploid set of genome have 13 chromosome number. Genotype Ãâ€" environment (GE) interactions have major role in development of improved cultivars. A cultivar is said to be commercially successful, if it performs well across the range of environments in which it grows. The differential response of a genotype or cultivar for a given trait across environments is defined as the genotype Ãâ€" environment interaction (G Ãâ€" E). Bilbro and Ray (1976) indicated that a successful breeding program should focus efforts on genotype yield level (average yield compared to standards), adaptation (what environment does the genotype best perform in), and stability (how consistent does the genotype yield compared to others). Genotype refers to the set of genes possessed by individual that is important for the expression of traits under investigation. The environment is defined as all non-genetic factor s that influence the expression of the trait and influence the growth and development of individuals. G Ãâ€" E interaction is a differential genotypic expression across environments (Basford and Cooper, 1998). According to Romagosa and Fox (1993), G x E interaction reduces association between phenotypic and genotypic values of a genotype. This may cause promising selections from one environment to perform poorly in one and better in another environment, forcing plant breeders to examine genotypic adaptation (Sharma et al., 1987). Varieties are tested in many environments due to changing their performance and adaptation ability. However, important G Ãâ€" E interactions decreases relationship between phenotype and genotype and also genetics improvements in breeding programmes (Comst... ... (1963) Genotype x environment interactions statistical genetics and plant breeding. Eds. Hanson, W. D. and Robinson H. F. National Academy of Science, National Research Council Publication, 982 : 164-196. Eberhart, S A and Russell R A (1966) Stability parameters for comparing varieties. Crop Science, 6 : 36-40. Lukonge E P (2005) Characterisation and diallel analysis of commercially planted cotton (Gossypium hirsutum l.) germplasm in Tanzania. Phd Thesis, University of the Free State, Bloemfontein, South Africa Myers G O (2004) Estimation of potential breeding value and genotype stability of cotton strains and varieties. http://www.cottoninc.com. Romagosa I and Fox, P N (1993) Genotype x environmental interaction and adaptation. In: M.D Hayward, N.O. Bosemark and I. Romagosa (Eds.), Plant breeding: Principles and Prospects pp 373-390. Chapman and Hall, London.