Characterisation of taro (Colocasia esculenta (L.) Schott) genetic resources in Southeast Asia and Oceania
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Morphological characterisation of 2,298 accessions collected in Indonesia, Malaysia, Thailand, Vietnam, the Philippines, Papua New Guinea and Vanuatu was conducted with 23 standardised descriptors and data bases were developed. More than 2,000 cultivars were electrophoresed on starch gels and six enzyme systems were revealed successfully (MDH, PGI, ICD, PGD, ME, SKDH). Each country selected a core sample for sharing composed of elite cultivars representing approximately 10% of the total number of accessions. Ploidy levels were determined using flow cytometry. AFLP fingerprinting was conducted on all cultivars included in the core sample. Meristems were excised and these genotypes were tissue cultured, indexed for DMV and distributed to participating countries. In Vanuatu, 378 cultivars were grown in a common plot, planted and harvested the same day, and their corms were boiled and submitted to a blind panel test composed of ten participants. Their eating quality was scored on a scale from 1 to 6 (excellent). The physico-chemical characteristics of 31 cultivars, representing different morphotypes and including excellent and poor cultivars, were analysed to assess the extent of variation existing for traits related to corm quality (dry matter content, minerals, lipids, proteins, gelatinisation temperature, amylose, glucose, fructose, saccharose, maltose and starch content). The results of these studies indicate that the genetic base of the cultivars is narrow. Only six zymotypes represent more than 51% of the total number of accessions electrophoresed and only 21 zymotypes represent more than the two thirds (70%) of the total number of accessions. AFLP analysis confirm the isozymes results and two distinct genepools are revealed, one in S.E. Asia and the other in the Pacific. It implies that crosses between accessions originating from only one country are not desirable and it is appropriate to cross cultivars from both genepools. Except for the temperature of gelatinisation, all physico-chemical characteristics are variable. Good taste is correlated with high dry matter, starch and amylose contents.
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- Bourrieau, M., 2000. Valorisation des Racines et Tubercules Tropicaux pour l'alimentation Humaine en Oceanie: le cas du laplap au Vanuatu. ENSIA-SIARC These de Master en Sciences, Gènie Agro alimentaire mediterraneen et tropical, 60 pages + annexes, Mars 2000.Google Scholar
- Bradbury J.H. and HollowayW.D. 1988. Chemistry of tropical root crops. significance for nutrition and agriculture in the Pacific. ACIAR, Canberra, ACIAR Monograph No. 6. 201 pp.Google Scholar
- Kreike, N. H. van Heck & V. Lebot. 2002. Genetic diversity in taro (Colocasia esculenta (L.) Schott) from South East Asia and Oceania. Submitted to Theoretical and Applied Genetics, in press.Google Scholar
- Lebot V. and Arhadya K.M. 1991. Isozyme variation in taro (Colocasia esculenta (L.) Schott) from Asia and the Pacific. Euphytica 56: 55-66.Google Scholar
- Lebot V., Hartati S., Hue N.T., Viet N.V., Nghia N.H., Okpul T. et al. 2000. Genetic variation in taro (Colocasia esculenta) in South East Asia and Oceania. Twelfth Symposium of the ISTRC. Potential of root crops for food and industrial resources. Sept. 10-16, 2000. Tsukuba, Japan, pp. 524-533.Google Scholar
- Nei M. and Li W-H. 1979. Mathematical model for studying genetic variation in terms of restriction endonucleases. Proc. Nat. Acad. Sci., USA 76: 569-5273.Google Scholar
- Prana M.S., Hartati N.S., Prana T.K. and Kuswara T. 2000. Evalua tion of Genetic Variation in Taro (C. esculenta (L.) Schott.) collected from West Java Using Isozyme Markers. Annales Bogoriensis n.s. 6: 80-87.Google Scholar
- Roger S.O. and Bendich A.J. 1988. Extraction of DNA from plant tissues. Plant Molecular Biology Manual A6: 1-10.Google Scholar
- TANSAO 2002. Final report. Contract no. ERBIC18CT970205 INCO DEV EU Directorate General 12. CIRAD Montpellier.Google Scholar
- Querro Garcia, J. 2000. Etude de la structuration de la variabilityé génétique du Taro. Mémoire de DEA, Institut National Agronomique de Paris Grignon, Sept 2000, 50 pages.Google Scholar
- Vos P., Hogers R., Bleeker M., Reians M., Van De Lee T., Hornes M. et al. 1995. AFLP. a new technique for DNA fingerprinting. Nucleic Acids Res. 23: 4407-4414.Google Scholar