Diversification of mulberry (Morus indica var. S۳۶), a vegetatively propagated tree species

Genetic diversity among plants sprouted from seven year old clones of mulberry (Morus indica var. S۳۶) was studied using molecular markers such as ISSR and RAPD. The clones showed significant variability in sex expression and the sprouting behavior. These changes were appeared after seven years of rigorous pruning and training (pruned once in every ۳-۴months). Genetic diversity analysis revealed significant DNA polymorphism differences among these clones. Through multiple regression analysis, four DNA markers associated with specific traits were identified. Cloning, sequencing and bioinformatics analyses suggested probable involvement of transposable elements along with enzymes and transcriptional regulating factors. The results of this preliminary report call for detailed analyses at biochemical, physiological and molecular levels coupled with inheritance pattern of these markers and their corresponding phenotypic traits. The markers identified for sprouting and sex expression are of much use in early identification of hybrids with the respective traits.   REFERENCES Bennetzen, J.L. (۲۰۰۰) Transposable element contribution to plant gene and genome evolution. Plant Mol. Biol. ۴۲, ۲۵۱-۲۵۹. Breto, M.P., Ruiz, C., Pina, J.A. and Asins, M.J. (۲۰۰۱) The diversification of Citrus clementina Hort. Ex Tan., a vegetatively propagated crop species. Mol. Phylogenet.  ۲۱, ۲۸۵-۲۹۳. Chatterjee, S.N., Nagaraja, G.M., Srivastava, P.P. and Naik, G. (۲۰۰۴) Morphological and molecular variation of Morus laevigata in India. Genetica. ۳۹, ۱۶۱۲—۱۶۲۴. Dandin, S.B., Susheelamma, B.N., Jolly, M.S., Mallikarjunappa, R.S. and Giridhar, K. (۱۹۸۳) Karyomorphological studies in a few varieties of mulberry (Morus spp.). National seminar on Silk Research and Development, Bangalore, March ۱۰-۱۳, ۱۹۸۳, p. ۳.  Das, B.K. and Mukherjee, S.K. (۱۹۹۲) Modification of sex expression in mulberry by colchicines-B, a potent antigibberllin. Indian J. Sericulture. ۳۱, ۱۷۳–۱۷۵. Felsenstein, J. (۱۹۹۳) PHYLIP (Phylogeny inference package) version ۳.۵c. Department of Genetics, University of Washington, Seattle. Genus, J. (۱۹۸۲) Plant steroid hormones-what are they and what they do. Trans Biochem. Sci. ۷, ۷-۹. Grandbastien, M.A. (۱۹۹۸) Activation of plant transposons under stress conditions. Trends Plant Sci. ۳, ۱۸۱-۱۸۷. Kasiviswanathan, K., Krishnaswami, S. and Choudhury, P.C. (۱۹۷۹) Long term studies on the cultivar, spacing and nitrogen fertilization for the improvement of yield potential of mulberry. Indian J. Sericulture. ۲۸, ۲۳-۲۹. Kreher, S.A., Fore, S.A. and Collins, B.S. (۲۰۰۰) Genetic variation within and among patches of the clonal species, Vacciniun syaminieum L. Mol. Ecol. ۹, ۱۲۴۷-۱۲۵۲. Lal, M. and Jaiwasl, V.S. (۱۹۸۸) Modification of flower sex and acid phosphatase activity by phthalimides in female plant of Morus nigra L. Plant Growth Regulation. ۷, ۲۹-۳۷. Nei, M. (۱۹۸۷) Molecular Evolutionary Genetics. Columbia University Press, New York.NY. Osborne, R. (۱۹۸۵) Sex change in cycads - hope for woodii, Encephalartos. ۲, ۲۰-۲۲. Persson, H.A. and Gustavsson, B.A. (۲۰۰۱) The extent of clonality and genetic diversity in lingonberry (Vaccinium vitisidaea L.) revealed by RAPDs and leafshape analysis. Mol Ecol. ۱۰, ۱۳۸۵-۱۳۹۷. Sastry, C.R. (۱۹۸۴) Mulberry varieties, exploitation and pathology. Sericologia. ۲۴, ۳۳۳-۳۵۹. Sneath, P.H.A. and Sokal, R.R. (۱۹۷۳) Numerical taxonomy. W. H. Freeman, San Francisco. Suyama, Y., Obayashi, K. and Hayashi, I. (۲۰۰۰) Clonal structure in a dwarf bamboo (Sasa senanensis) population inferred from amplified fragment length polymorphism (AFLP) fingerprints. Mol. Ecol. ۹, ۹۰۱-۹۰۶. Tikader, A., Vijayan, K., Raghunath, M.K., Chakraborti, S.P., Roy, B.N. and Pavankumar, T. (۱۹۹۵) Studies on sexual varieties in mulberry (Morus spp ). Euphytica. ۸۴, ۱۱۵-۱۲۰. Vijayan. K. and Chatterjee S.N. (۲۰۰۳) ISSR profiling of Indian cultivars of mulberry (Morus spp.) and its relevance to breeding programs, Euphytica. ۱۳۱, ۵۳-۶۳. Wessler, S.R. (۱۹۹۶) Plant retrotransposons: Turned on by stress. Curr. Biol. ۶, ۹۵۹- ۹۶۱. Wu, J., Krutovskii, K.V. and Strauss, S.H. (۱۹۹۹) Nuclear DNA diversity, population differentiation, and phylogenetic relationnships in the California closed-cone pines based on RAPD and allozyme markers. Genome. ۴۲, ۸۹۳-۹۰۸. Wright, S. (۱۹۷۸) Evolution and Genetics of populations. Vol.۴. Variability within and among natural populations. University of Chicago Press, Chicago. Yang, L., Yang, S.T., Weid, X.H. and Gui, J.F. (۲۰۰۱) Genetic diversity among different clones of the gynogenetic silver crucian curp, Carassius auratusgibetio, revealed by transferrin and isozyme markers. Biochem. Genet. ۳۹, ۲۱۳-۲۲۵.

کلیدواژه ها:

Genetic diversity ، ISSR ، Mulberry ، RAPD ، Somatic mutation