NATURE OF GENETIC DIVERGENCE AMONG SOME COTTON GENOTYPES
Abstract
Inherent divergence and parenthood of germplasm could play an important role in genetic improvement of cotton. The present investigation was conducted to assess the genetic divergence among fourteen locally cotton genotypes and six exotic genotypes using multivariate Mahalanobis D2 statistics and metroglyph analysis. The results showed highly significant differences among these genotypes for all the studied quantitative characters. The Mahalanobis D2 statistics showed that the dissimilarity coefficients were significant and highly significant, which ranged from 3.263 to 190.89, indicating highly genetic divergence for these cotton genotypes. Seed cotton yield and fiber strength were account about 83% of total genetic divergence. The metroglyph analysis grouped these genotypes into eight different clusters based on seven quantitative cotton characters. The inter-cluster D2 values ranged from 11.381 to 178.902 between these groups, while, the intra-cluster D2 values ranged from 3.263 to 47.806 within each group. On the basis of this grouping, it was concluded that hybridization between genotypes of different clusters might be expected to give new genetic recombinants for different economic characters. These informations could be utilized for hybridization between distinct genotypes to increase genetic cotton variability.References
Abd El-Baky, A. M. A. (2006). Genetic consequences of incorporating foreign genes into some Egyptian cottons. M.Sc Thesis, Fac., Agric., Zagazig Univ., Egypt.
Abd El-Sayyed, S. M., S.M. Mahgoub, M. A. Rafaat and A. M. Abd El-Moghny (2006). Genetic consequences of incorporating foreign genes into some Egyptian cottons. Zagazig J. Agric. Res., 33: 71-82.
Anderson, E. (1957). A semigraphical method for the analysis of complex problem. Proc. Nat. Acad. Sci. Wash. 43: 923-927.
Chandra, S. (1977). Comparison of mahalanobis's method and metroglyph technique in the study of genetic divergence in Linum usitatissimum L. germplasm collection. Euphytica, 26: 141-148.
Haidar, S., A. Muhammad, M. Hassan; M. H. Hafiz and A. Ditta (2012). Genetic divergence among upland cotton genotypes for different economic traits and response to cotton leaf curl virus (Clcv) disease. Pak. J. Bot., 44: 1779-1784.
Khan, M. R., A. Samad, S. Begum, S. Khaleda, A. K .M. S. Alam, A. N. Chowdhury and M. Z. Rahman (2007). Metroglyph Analysis in Cotton (Gossypium Sp.). Bangladesh J. Sci. Ind. Res., 42: 449-454.
Parresuman and R. S. Patil (2014). Studies on genetic divergence in intrahirsutum hybrids of early segregating generation (F3) in upland cotton (Gossypium hirsutum L.). International, J. Dev. Res., 4: 781-783.
Rao, C. R. (1952). Advanced Statistical Methods in Biometric Research. John Wiley and Sons, New York.
Shakeel1, A., J. Farooq, M. A. Ali, M. Riaz, A. Farooq, A. Saeed and M. F. Saleem (2011). Inheritance pattern of earliness in cotton (Gossypium hirsutum L.). Australian J. Crop Sci., 5:1224-1231.
Singh, R. K. and B. D. Chaudhary (1979). Biometrical Methods in Quantitative Genetic Analysis. Kalyani Publishers, New Delhi, India.
Steel, R. G. D., J. H. Torrie and D. A. Dicky (1997). Principles and Procedures of Statistics. A Biometrical Approach. Second Edition. McGraw Hill Book Company. Inc. New York, USA.
Thiyagu, K., N. M. Boopathi, N. Nadarajan, A. Gopikrishnan, P. Selvakumar, S. Magadum and R. Ravikesavan (2011). Sampling and exploitation of genetic variation exist in locally adapted accessions using phenotypic and molecular markers for genetic improvement of cotton. Gene Conserve J., 10: 129-153.
