Traditional banana diversity in Oceania: an endangered heritage

This study aims to understand the genetic diversity of traditional Oceanian starchy bananas in order to propose an efficient conservation strategy for these endangered varieties. SSR and DArT molecular markers are used to characterize a large sample of Pacific accessions, from New Guinea to Tahiti and Hawaii. All Pacific starchy bananas are shown of New Guinea origin, by interspecific hybridization between Musa acuminata (AA genome), more precisely its local subspecies M. acuminata ssp. banksii, and M. balbisiana (BB genome) generating triploid AAB Pacific starchy bananas. These AAB genotypes do not form a subgroup sensu stricto and genetic markers differentiate two subgroups across the three morphotypes usually identified: Iholena versus Popoulu and Maoli. The Popoulu/Maoli accessions, even if morphologically diverse throughout the Pacific, cluster in the same genetic subgroup. However, the subgroup is not strictly monophyletic and several close, but different genotypes are linked to the dominant genotype. One of the related genotypes is specific to New Caledonia (NC), with morphotypes close to Maoli, but with some primitive characters. It is concluded that the diffusion of Pacific starchy AAB bananas results from a series of introductions of triploids originating in New Guinea area from several sexual recombination events implying different genotypes of M. acuminata ssp. banksii. This scheme of multiple waves from the New Guinea zone is consistent with the archaeological data for peopling of the Pacific. The present geographic distribution suggests that a greater diversity must have existed in the past. Its erosion finds parallels with the erosion of cultural traditions, inexorably declining in most of the Polynesian or Melanesian Islands. Symmetrically, diversity hot spots appear linked to the local persistence of traditions: Maoli in New Caledonian Kanak traditions or Iholena in a few Polynesian islands. These results will contribute to optimizing the conservation strategy for the ex-situ Pacific Banana Collection supported collectively by the Pacific countries

Polymotu : A new concept of island-based germplasm bank based on an old Polynesian practice

The Polymotu concept (poly=many, motu=island) is to use the geographical isolation of special sites for conservation and reproduction of individual varieties of plants, trees and even animals. This concept is mainly derived from previous initiatives in conservation of coconut palms by ancient Polynesians and some contemporary Thais. A quite similar concept has also been used by New Zealanders for conservation of endangered bird species. For instance, when a small island is planted with only one variety of coconut palms, breeding occurs only within this variety and certified seednuts are naturally produced. Conservation is secured by both the geographical isolation of the islands and the availability of certified seednuts. In 2009, the Polymotu concept was included in the global coconut conservation strategy developed by the International Coconut Genetic Resources Network (COGENT) and the Global Crop Diversity Trust. It moves this global strategy towards the involvement of more countries, sites and stakeholders. The Polymotu concept was enriched in 2010 during a visit in Samoa, in order for farmers to diversify their genetic resources and increase their incomes. We are presently launching initiatives to develop Polymotu in various regions: the Kepulauan Seribu National Park at the north of Jakarta, Indonesia; the Fakarava biosphere reserve and the Tetiaroa atoll in French Polynesia, Fiji and Samoa. Factors influencing the acceptance of Polymotu by the various stakeholders are discussed, together with collaborative research to be conducted during implementation of the projects. This paper discusses the origins and precursors of the Polymotu concept; presents the firsts initiatives to launch research actions linked to the Polymotu project, and discusses the need for further research to fully implementation this concept

Carotenoid content and traditional knowledge of breadfruit cultivars of the Republic of the Marshall Islands

Vitamin A deficiency (VAD) and non-communicable diseases including cancer, heart disease and diabetes, are serious health problems in the Republic of the Marshall Islands (RMI), a small island nation of the Pacific. These health problems are related to the trend towards over-consumption of unhealthy imported processed foods and neglect of traditional foods. Breadfruit (Artocarpus altilis and Artocarpus mariannensis) is the most widely available traditional starch food for Marshall Islands people. The ripe fruit flesh is yellow or sometimes orange, as with the Mejwaan cultivar, indicative of carotenoid content. Carotenoid-rich foods can protect against VAD and non-communicable diseases. Yet little information on carotenoid content of Marshallese breadfruit cultivars is available. This study documents traditional knowledge of breadfruit cultivars using ethnography, and analyzed 6 breadfruit cultivars of 2 species, A. altilis and A. mariannensis, for provitamin A (β- and α-carotene) and total carotenoid content, of using high performance liquid chromatography (HPLC). The ripe seeded breadfruit Mejwaan contained strikingly rich concentrations of β-carotene (3540 μg/100 g fresh weight). Samples of other ripe and mature cultivars, characterized by lighter-colored flesh, contained-medium to low-carotenoid content (<5–102 μg/100 g fresh weight). As samples were harvested from field-grown plants, it should be noted that the quantity of carotenoids may vary when the same cultivars are planted in different sites. Local experts reported that Mejwaan was once common but is now becoming rare, and that people are now consuming its ripe flesh much less frequently; the discovery of Mejwaan's rich carotenoid content should be used to promote this cultivar for its important health benefits