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United States Department of Agriculture

Agricultural Research Service

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Research Project: Research on Papaya to Be Exported to Japan and Characterization and Preservation of Hawaiian Taro Cultivars

Location: Tropical Plant Genetic Resources and Disease Research

2013 Annual Report


1a.Objectives (from AD-416):
The genetically engineered papaya has been commercialized in Hawaii since 1998 and now is close to being deregulated in Japan, which will allow the export of genetically engineered papaya to Japan in 2010. The exportation of the transgenic papaya is being headed by the Hawaii Papaya Industry Association (HPIA). With taro, controversy over genetic engineering has occurred, with a significant part involving cultural aspect of Hawaiian taro as it relates to the Hawaiian race. The objectives of this proposal are to.
1)To assess the impact labeling and marketing strategies that are deployed by HPIA on the commercialization of the transgenic papaya in Japan, and.
2)further characterize the native Hawaiian taro cultivars using molecular markers, and to develop genetic maps of six Hawaiian taro varieties and two ex-Hawaii strains.


1b.Approach (from AD-416):
Transgenic papaya: A close collaborative effort will be made with HPIA as it markets the transgenic papaya in Japan. A sample of grocery stores in Japan will be used to study the impact of labeling on sales of transgenic papaya. The sales of GM and nonGMO papaya will be monitored and recorded. It is anticipated that the research objective will be completed within the first two years of introduction of the transgenic papaya to Japan. Hawaiian taro: Efforts will be made at collecting, cloning, and storing the taro germplasm at UH Hilo under tissue culture conditions in order to lower the costly maintenance of taro under field conditions. Available microsatellite markers will be used in differentiating the Hawaiian varieties. Pyrosequencing will be done of selected cultivars to provide the rapid acquisition of very large volumes of DNA sequence information, which will be used in nucleotide polymorphism to identify the taro cultivars. Documents SCA with U of HI. Formerly 5320-21000-011-05S (9/09). Formerly 5320-21000-011-17S (11/10). Formerly 5320-21000-013-07S (05/13).


3.Progress Report:

The goal of this agreement is to carry out a collaborative research effort among the Pacific Basin Agricultural Research Center (PBARC), The College of Agriculture, Forestry and Natural Resource Management(CAFNRM) at the University of Hawaii at Hilo (UHH), and the College of Tropical Agriculture and Human Resources (CTAHR) at the University of Hawaii at Manoa (UHM) that addresses important agriculture problems in Hawaii which directly contributes to objectives 1 of the in-house project, "Develop and assess transgenic plants to control plant growth and development, disease resistance, and shelf life".

Artificial raised lo’i kalo, Colocasia, aquaponic system: Harvesting of the first crop of taro is complete and data have been collected for analysis. The weight of the clumps averaged 10 kg. with good growth using only the waste water from the sturgeon tanks. Because of the large size of the clumps from each plantlet, harvesting required walking on the thin 6 mil plastic. Replanting the lo’i to determine life of the 6 mil plastic designing a new system using butyl rubber for the lining with tilapia tanks as the nutrient source (tilapia are presently in Micronesia) was completed in September.

Giant swamp taro, Cyrtosperma, hydroponic tank system: A greenhouse enclosed 4’X8’X1’ tank system for testing of Cyrtosperma plants for salt tolerance has been completed. Disease free tissue culture plants have also arrived and are presently being multiplied.

These tanks are presently being used to test a reported salt tolerant taro plant variety from Hawaii.

Giant taro Alocasia as aquaculture feed stock: Disease free plantlets of the Alocasia variety ‘Tonga” have arrived and will be planted in October to retest production levels. In a study from Hawaii (Foliaki, et al., 1990), ‘Tonga” produced 78,400 kilograms of stem per production hectare. Stems of Alocasia from other areas of the world average 16 to 21% starch (Sakai, 1983) which would mean that ‘Tonga’ may produce more starch per hectare than wheat.

Nutrient levels in water samples and wells from flooded and unflooded atolls: It is difficult to interpret these samples, mostly because of the coral (calcium carbonate, Ca++, CO3--) base rock and the completely organic soil, with high cation holding capacity. Salt water contains sodium chloride (Na+, Cl-) and also moderate levels of Magnesium (Mg++) and potassium (K+). The cation exchange layers of the organic soil hold on to the calcium and magnesium most tightly and the potassium less, with the sodium the least. When seawater floods the lagoon the completely organic soil holds onto the magnesium and calcium the most, the potassium less tightly and the sodium the least. So the sodium would be most available for uptake by the plants with potassium also available. The calcium and magnesium would be less available, but because the base rock is calcium carbonate, calcium would always be available. This leaves magnesium as the least available. The levels of nutrients in the water samples appear to show these results.


Last Modified: 9/20/2014
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