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Journal of Biological Sciences

Year: 2003 | Volume: 3 | Issue: 9 | Page No.: 773-781
DOI: 10.3923/jbs.2003.773.781
Local Population Differentiation in Trifolium alexandinum L. in Response to Various Disturbance Regimes
Seema Mahmood and Asad Abbas

Abstract: Local population differentiation was studied in twenty populations of Trifolium alexandrinum L. Ten population were sampled from undisturbed sites while the other ten were collected from a variety of disturbed habitats. Each individual plant was regarded as genet and was analyzed for various biometric traits by taking consistent measurements for all characteristics. The biometric analyses revealed considerable phenotypic variability for a majority of morphological expressions. A significant differentiation between populations was found in response to local habitat conditions. This study suggested that phenotypic differentiation in T. alxandrinum was strongly influenced by environmental disturbance. Therefore, disturbance seems to play a major role in the generation of variation. The occurrence of phenotypic modification in response to environment was regarded as phenotypic plasticity and it appeared to be an important feature of adaptation to environmental fluctuation. This study concluded that the persistence of the species in spatially and temporally disturbed habitats presumably depends on the variability of certain morphological expressions.

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How to cite this article
Seema Mahmood and Asad Abbas, 2003. Local Population Differentiation in Trifolium alexandinum L. in Response to Various Disturbance Regimes. Journal of Biological Sciences, 3: 773-781.

Keywords: Distrubance, biometric traits, plasticity and trifolium alexandrinum

REFERENCES

  • Aston, J.L. and A.D. Bradshaw, 1966. Evolution in closely adjacent plant populations. II Agrostis stolonifera in maritime habitats. Heredity, 21: 649-664.
    CrossRef    Direct Link    


  • Bazzaz, F.A., 1996. Plants in Changing and Environments: Linking Physiological, Population and Community Ecology. Cambridge University Press, London


  • Bradshaw, A.D., 1959. Population differentiation in Agrostis tenuis sibth I. morphological variation. New Phytol., 58: 208-227.
    Direct Link    


  • Bradshaw, A.D., 1965. Evolutionary significance of phenotypic plasticity in plants. Adv. Genet., 13: 115-155.
    Direct Link    


  • Bradshaw, A.D., 1974. Environment and phenotypic plasticity. Brookhaven Symp. Biol., 25: 74-94.


  • Brown, A.D.H., 1979. Enzyme polymorphism in plant populations. Theor. Pop. Biol., 15: 1-42.
    CrossRef    


  • Burdon, J.J., 1980. Intra-specific diversity in natural population of Trifolium repens. J. Ecol., 68: 717-735.
    Direct Link    


  • Evans, R.C. and R. Turkington, 1988. Maintenance of morphological variation in a biotically patchy environment. New Phytol., 109: 369-376.
    Direct Link    


  • Hedrick, P.W., M.E. Ginewan and E.P. Ewing, 1976. Genetic polymorphism in heterogeneous environment. Ann. Rev. Ecol. Syst., 7: 1-32.
    CrossRef    Direct Link    


  • Hill, J., 1977. Plasticity of white clover grown in competition with rye grasses. Report of The Welsh Plant Breeding Station for 1976, Aberystwyth.


  • Langlet, O., 1971. Two hundred years of gynecology. Taxon, 20: 653-722.


  • Levins, R., 1968. Evolution in changing environments: Some theoretical exploration. Princeton University Press, Princeton


  • Linhart, Y.B., J.B. Mitton, K.B. Sturgeon and M.L. Davis, 1981. Genetic variation in space and time in a population of ponderosa pine. Heredity, 46: 407-426.
    CrossRef    Direct Link    


  • Marshall, D.R. and S.K. Jain, 1968. Phenotypic plasticity of Avena fatua and A. barbata. Am. Naturalist, 102: 457-467.
    Direct Link    


  • Newton, P.C.D., 1986. The establishment, growth and fate of white clover with special reference to physiology of stolon growth. Ph.D. Thesis, University of Wales, UK.


  • Schlichting, C.D., 1986. The evolution of phenotypic plasticity in plants. Ann. Rev. Ecol. Syst., 17: 667-693.
    CrossRef    Direct Link    


  • Schmid, B., 1992. Phenotypic variation in plants. Evolutionary Trends Plants, 6: 45-60.


  • Stebbins, G.L., 1951. Variation and evolution in plants. Columbia Univ. Press, New York


  • Thompson, J.D., 1991. Phenotypic plasticity as a component of evolutionary change. Trends Ecol. Evol., 6: 246-249.
    CrossRef    


  • Turkington, R., 1983. Plasticity in growth of dry matter distribution of two genotypes o f Trifolium repens grown in different environments of neighbours. Can. J. Bot., 61: 2186-2195.


  • Turkington, R. and J.J. Burdon, 1983. The biology of Canadian weeds. 57. Trifolium repens. Can. J. Plant Sci., 63: 243-266.


  • Turkington, R. and J.L. Happer, 1979. The growth, distribution and neighbour relationships of Trifolium repens in permanent pastures. IV. Fine scale biotic differentiation. J. Ecol., 67: 244-254.
    Direct Link    


  • Bazzaz, F.A., 1983. Characteristics of Populations in Relation to Disturbance in Natural and Man Modified Ecosystems. In: Disturbance and Ecosystems, Mooney, H.A. and M. Gordon (Eds.). Springer Verlag, Berlin, pp: 259-257


  • Hamrick, J.L., 1983. The Distribution of Genetic Variations Within and Among Natural Plant Populations. In: Genetics and Conservation, Schonewald-Cox, C.M., S.M. Chambers, B. Macbryde and L. Thomas (Eds.). Benjamin-Cunnings, Menlo Park, New Jersey, pp: 335-348


  • Brougham, R.W., P.R. Ball and W.M. Williams, 1978. The Ecology and Management of White Clover Based Pastures. In: Plant Relations in Pastures, Williams, J.R. (Ed.). CSRO, Melbourne, pp: 309-324


  • Thompson, J.D., 1990. Morphological Variation Among Natural Populations of Spartina anglica. In: Spartina Anglica Research Reviews, Gray, A.J. and P.E.M. Benham (Eds.). HMSO, London, pp: 26-33


  • Levin, S.A. and R.T. Paine, 1974. Disturbance patch formation and community structure. Proc. Nat. Acad. Sci., 71: 2744-2747.


  • Watson, M.A., M.J.M. Hay and P.C.D. Newton, 1997. Developmental Phenology and the Timing of Determination of Shoot and Buds Fates: Ways in which the Developmental Programme Modulates Fitness in Clonal Plants. In: The Ecology and Evolution of Clonal Plants, Kron, H. and J. Groenendael (Eds.). Backhuys Publishers, Leiden, The Netherlands, pp: 31-53

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