RAPD
markers were used to estimate levels of genetic diversity and structure among
twelve East African Tall (EAT) coconut (Cocos nucifera L.) accessions
that are maintained at Chambezi station. Ten primers were used in the analysis
of 120 accessions. Cluster analysis was performed based on Jaccard’s coefficient
and Nei genetic distances. Further analyses included principal coordinate
analysis (PCA) and finally bootstrap analysis. The cluster analysis revealed
two main clusters. One cluster contained provenances from Lindi and Mtwara
regions (south) and those from Coast and Dar
es Salaam regions (central); the second had
provenances from Tanga region, which is the northern part of the coastal belt.
A similar distribution of provenances was shown by the results of the principal
coordinate analysis, whose first three coordinates explained 56% of the total
variation. The results were able to discriminate between the different
provenances and provide evidence of the different origins for the coconut palms
in the northern and southern parts of coastal coconut-growing belt. The two
major clusters concur well with the history and distribution of coconuts in the
coastal belt of Tanzania.
References
[1]
Persley, G.J. (1992) Replanting the Tree of Life. Towards an International Agenda for Coconut Palm Research. Redwood Press Ltd., Melksham.
[2]
Ashburner, G.R., Thompson, W.K. and Halloran, G.M. (1997) RAPD Analysis of South Pacific Palm Populations. Crop Science, 37, 992-997. http://dx.doi.org/10.2135/cropsci1997.0011183X003700030048x
[3]
Rohde W., Kullaya, A., Rodriguez, J. and Ritter, E. (1995) Genome Analysis of Cocos nucifera L. by PCR Amplification of Spacer Sequences Separating a Subset of copia-Like EcoRI Repetitive Elements. Journal of Genetics and Breeding, 49, 179-186.
[4]
Katsuyuki, I., Megumi, H., Noriyuki, K., Hiroshi, N., Michio, O., Katsui, T. and Shigeto, T. (2003) Genetic Diversity of Coconuts (Cocos nucifera L.) in Yap State. Kagoshima University Research Centre for the Pacific Islands Occasional Papers No. 39, Kagoshima, 45-49.
[5]
Perera, L., Russel, J. R., Provan, J. and Powell, W. (2000) Use of Micro Satellite DNA Markers to Investigate the Level of Genetic Diversity and Population Genetic Structure of Coconut (Cocos nucifera L.). Genome, 43, 15-21. http://dx.doi.org/10.1139/g99-079
[6]
Doyle, J.J. and Doyle, J.L. (1990) Isolation of Plant DNA from Fresh Tissue. Focus, 12, 13-15.
[7]
Jaccard, P. (1908) Nouvelles recherches sur la distribution floralle. Bulletin de la Société Vaudoise des Sciences Naturelles, 44, 223-270.
[8]
Sneath, P.H.A. and Sokal, R.R. (1973) Numerical Taxonomy. W. H. Freeman & Co, San Francisco.
[9]
Nei, M. (1978) Estimation of Average Heterozygosity and Genetic Distance from a Small Number of Individuals. Genetics, 89, 583-590.
[10]
Nei, M., Tajima, F. and Tateno, Y. (1983) Accuracy of Estimated Phylogenetic Trees from Molecular Data. Journal of Molecular Evolution, 19, 153-170. http://dx.doi.org/10.1007/BF02300753
[11]
Schuiling, M. (1991) The History of Coconut Growing and Lethal Disease in the Coastal Districts of Mainland Tanzania and Its Possible Relevance to Disease Resistance in the Local East African Tall. National Coconut Development Programme, Dar es Salaam.
[12]
Schuiling, M. (1992) Final Report of GTZ Plant Pathologist’s Research on Lethal Disease from January 1980-June 1992. National Coconut Development Programme, Dar es Salaam.
