Taro networks and seed systems: promoting the use of diversity for crop improvement

Taro production in Samoa was devastated with the 1993 taro leaf blight (TLB) outbreak, destroying a crop vital for food security and foreign exchange. Exotic taro cultivars from the northern Pacific and the Philippines, with reported TLB tolerance, were introduced and used to establish a TLB horizontal resistance breeding programme. However, despite their positive impact the need to enrich a potentially narrow gene pool to prevent future disasters was recognized. More diversity from Southeast Asia was introduced via a Pacific regional genebank in 2004. Unlike previous breeding cycles, progeny which incorporated these new introductions from Asia showed a huge diversity in types. The new progeny, when evaluated, demonstrated improved TLB resistance and palatability, higher yields, better quality (yellow-fleshed corms) and importantly are well liked by many people in Samoa. Further, a cost benefit analysis clearly showed that the cumulative result of the largely publically-funded taro crop improvement programme far outweighed costs. The access and use of non-Pacific diversity was made possible through formal and informal seed systems, and the existence of regional networks linking Samoa to other Pacific countries and Asia. A recently established global network for edible aroids means that these improved taro cultivars are now being cultivated in Africa, Asia and Latin America. The existence of such networks and genetic diversity will become increasingly important with climate change reinforcing interdependence and the need for global connectivity. This paper discusses the importance of formal and informal approaches to crop improvement, using the case study of taro in Samoa as an example.