Adapting clonally propagated crops to climatic changes: a global approach for taro (Colocasia esculenta (L.) Schott)
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Clonally propagated crop species are less adaptable to environmental changes than those propagating sexually. DNA studies have shown that in all countries where taro (Colocasia esculenta (L.) Schott) has been introduced clonally its genetic base is narrow. As genetic variation is the most important source of adaptive potential, it appears interesting to attempt to increase genetic and phenotypic diversity to strengthen smallholders’ capacity to adapt to climatic changes. A global experiment, involving 14 countries from America, Africa, Asia and the Pacific was conducted to test this approach. Every country received a set of 50 indexed genotypes in vitro assembling significant genetic diversity. After on-station agronomic evaluation trials, the best genotypes were distributed to farmers for participatory on-farm evaluation. Results indicated that hybrids tolerant to taro leaf blight (TLB, Phytophthora colocasiae Raciborski), developed by Hawaii, Papua New Guinea and Samoa breeding programmes outperformed local cultivars in most locations. However, several elite cultivars from SE Asia, also tolerant to TLB, outperformed improved hybrids in four countries and in one country none of the introductions performed better than the local cultivars. Introduced genotypes were successfully crossed (controlled crossing) with local cultivars and new hybrids were produced. For the first time in the history of Aroids research, seeds were exchanged internationally injecting tremendous allelic diversity in different countries. If climatic changes are going to cause the problems envisaged, then breeding crops with wide genetic diversity appears to be an appropriate approach to overcome the disasters that will otherwise ensue.
KeywordsAllelic diversity Colocasia esculenta Crossing In vitro distribution On-farm evaluation Selection
This research was financially supported by the Europe-Aid project “Adapting clonally propagated crops to climatic and commercial changes” (Grant No. DCI-FOOD/2010/230-267 SPC). Thanks are due to the 14 different countries technicians working on research stations and to farmers and their families for their enthusiastic contribution.
Compliance with ethical standards
Conflict of interest
The authors declare that they have no conflict of interest.
- Birnbaum K (2006) Crop genetics on modern farms: gene flow between crop populations. In: Motley TJ, Zerega N, Cross H (eds) Darwin's harvest: new approaches to the origins, evolution, and conservation of crops. Columbia University Press, New York, pp 333–346Google Scholar
- Brush SB (2000) Genes in the field: on-farm conservation of crop diversity. Lewis Pubs, Boca RatonGoogle Scholar
- Chaïr H, Traoré RE, Duval MF, Rivallan R, Mukherjee A, Aboagye LM, Van Rensburg WJ, Andrianavalona V, Pinheiro de Carvalho MAA, Saborio F, Sri Prana M, Komolong B, Lawac F, Lebot V (2016) Genetic diversification and dispersal of taro (Colocasia esculenta (L.) Schott). PloS ONE 11(6):1–19CrossRefGoogle Scholar
- Cho JJ (2004) Breeding Hawaiian taros for the future. In: Guarino L, Taylor M, Osborn T (eds) Proceedings of the 3rd taro symposium held in Nadi, Fiji. Secretariat of the Pacific Community, pp 192–196Google Scholar
- FAO (2014) FAO Statistical database. www.fao.org visited Feb 2014
- Fonoti P (2005) Breeding resistance to taro leaf blight (Phytophthora colocasiae) in Samoa. Masters of Crop Science Thesis, USP, Alafua, July, 2005Google Scholar
- Harding RM, Revil PA, Hafner GJ, Yang I, Maino MK, Devitt LC, Dowling ML, Dale JL (2004) Characterisation of taro viruses and the development of diagnostic tests. In: Guarino L, Taylor M, Osborn T (eds) Proceedings of the 3rd taro symposium held in Nadi, Fiji. Secretariat of the Pacific Community, pp 98–101Google Scholar
- Iosefa T, Taylor M, Hunter D, Tuia V (2012) The taro improvement programme in Samoa: sharing genetic resources through networking. FAO RAP-NIAS: plant genetic resources in Asia and the Pacific: impacts and future. In: Proceedings of a symposium held in Tsukuba, Japan. 18th Oct 2011-FAO-p, pp 25–40Google Scholar
- Ivancic A, Lebot V (2000) Taro (Colocasia esculenta): genetics and breeding. Collection “Repères”, CIRAD, Montpellier, FranceGoogle Scholar
- Lebot V, Aradhya M (1991) Isozyme variation in taro (Colocasia esculenta (L.) Schott) from Asia and Oceania. Euphytica 56:55–66Google Scholar
- Matsuda M (2002) Taro, Colocasia esculenta (L.) Schott, in Eastern Asia: its geographical distribution and dispersal into Japan. Doctoral Thesis, Kyoto University, Kyoto, JapanGoogle Scholar
- Matthews PJ, Lockhart PJ, Ahmed I (2017) Phylogeography, ethnobotany and linguistics issues arising from research on the natural and cultural history of taro, Colocasia esculenta (L.) Schott. Man India 97(1):353–380Google Scholar
- Singh D, Okpul T (2000) Evaluation of 12 taro (Colocasia esculenta (L.) Schott) leaf blight resistant lines for yield and eating quality in Papua New Guinea. SABRAO J Breed Genet 32(1):39–45Google Scholar
- Taylor MB (2002) The establishment of a regional germplasm centre in the Pacific island region. In: Engels JMM, Rao VR, Brown AHD, Jackson MT (eds) Managing plant genetic diversity. CAB International, Oxon, pp 104–112Google Scholar
- Taylor MB, Tuia V, Sant R, Lesione E, Prasad R, Prasad RL, Vosaki A (2004) Using in vitro techniques for the conservation and utilization of Colocasia esculenta var. esculenta (taro) in a regional genebank. In: Guarino L, Taylor M, Osborn T (eds) Proceedings of the 3rd taro symposium held in Nadi, Fiji. Secretariat of the Pacific Community, pp 69–73Google Scholar
- Zettler FW, Jackson GVH, Frison EA (eds) (1989) FAO/IBPGR technical guidelines for the safe movement of edible aroid germplasm. Food and Agriculture Organization of the United Nations, Rome/International Board for Plant Genetic Resources, RomeGoogle Scholar