Progress 09/01/09 to 08/31/12
Outputs
OUTPUTS: The effect of new postharvest treatments were compared on three newer cultivars of Anthuriums, New Pahoa Red, Hokuloa (Pink), and Tropic Ice, a green spathed cultivar. For all three varieties in both tests showed phytotoxic symptoms and very short postharvest life when treated with the anti-ethylene compound 1 MCP (1 methylcyclopropene). 1 MCP has been shown to significantly extend the postharvest life of other ornamental flowers. This treatment cannot be recommended for use on Anthuriums. The cytokinin, benzyladenine, and the newer compound thioduran (TDZ) were the best treatments to extend postharvest spathe life as a dip and in the vase solution, respectively. Cost of TDZ at the moment may not make it cost effective when compared to benzyladenine. The Floralife vase solution (Hydroflor) for 1 hour gave no improvement in maintaining spathe life when compared to the water control. The leaf shine spray (Floralife, Finishing Touch) has potential in maintaining spathe colour and gloss, and reducing spathe blueing. The exception with the leaf shine spray was Tropic Ice when treated, flowers started to lose appearance sooner than the non-treated control. Honohono orchids (Dendrobium anosmum D. superbum) are widely cultivated in Hawaii, and like other orchids, are often infected with viruses. The most common viruses that infect honohono orchids are Cymbidium mosaic virus (CyMV) and Odontoglossum ringspot virus (ORSV) that are both spread mechanically, usually by cultural practices. Within the last year, we have found another virus in honohono orchids that has not been previously reported from any orchid cultivars in Hawaii. Most closely related to Watermelon mosaic virus (WMV), this new virus in honohono is ninety-three percent identical to WMV and distinct from the closely related Dendrobium mosaic virus (DeMV) that has been previously reported infecting honohono orchids in Hawaii. WMV has only been reported to infect orchids of the genus Vanilla on islands in the South Pacific, where it is an economically important problem. There have been no previous reports of WMV infecting orchids of any genera in Hawaii. Both WMV and DeMV are potyviruses that are transmitted by several species of aphids that are present in Hawaii, and therefore have the potential for widespread dispersal. PARTICIPANTS: Principal Investigators: Paul Singleton, University of Hawaii, College of Tropical Agriculture and Human Resources (CTAHR). John Hu, University of Hawaii, CTAHR. Michael Melzer, University of Hawaii, CTAHR. Robert Paull, University of Hawaii, CTAHR. Tessie Amore, University of Hawaii, CTAHR. Joanne Licthy, University of Hawaii, CTAHR. Janice Uchida, University of Hawaii, CTAHR. David Christopher, University of Hawaii, CTAHR. Kent Kobayashi, University of Hawaii, CTAHR. Partner Organization: Judy Zhu, Hawaii Agriculture Research Center. TARGET AUDIENCES: Hawaii Anthurium Industry Association, Hawaii Tropical Flower Council, Hawaii Florists and Shippers Association, Big Island Association of Nurserymen, Orchid Growers of Hawaii, Hawaii Tropical Flower and Foliage Association, Protea Growers Association of Hawaii. Information is disseminated through yearly review meetings which include progress reports, site visits, and laboratory tours presented by the principal investigators listed above. PROJECT MODIFICATIONS: Not relevant to this project.
Impacts
Optimum postharvest handling is essential to maintain the quality and to prolong the vase life of cut flowers and foliage. The market for tropical flowers and foliage is very competitive and it is necessary to continuously review product mix, product quality, and postharvest procedures. Research on postharvest cut flower and hydration solutions and vase solutions were carried out nearly 20 years ago and new varieties are now being grown. These postharvest treatments need to be reevaluated and recommendations updated. This proposal's final goal was to evaluate new postharvest treatment to maintain quality and extend the vase life of Hawaii's cut flowers and foliage. The data from this comparison can be used to expand Hawaii's competitive advantages and develop newer competitive niches. The use of the widely recommended anti ethylene compound 1 MCP should be avoided for anthuriums and protea and only shows some positive effects on some orchid varieties. Hydroflor designed to enhance water uptake by flowers after harvest has positive effects on some orchids. Glucose treatments are still the best postharvest treatment for proteas to limit postharvest leaf blackening coupled to harvest at the right maturity. Benzladenine is still the best postharvest treatment to maintain postharvest life of Anthuriums. BBrMV is the causal agent of banana bract mosaic disease in banana in several banana growing regions around the world. However, the isolate we have identified in Hawaii is infecting members of the ginger family, Zingiberaceae. Determining the disease etiology, mode of spread, distribution throughout the Hawaiian Islands, and the resistance or susceptibility of economically important ginger varieties or closely related plant hosts such as heliconia, birds of paradise, and traveler's palm, among others, will provide the knowledge necessary to develop the management strategies for mitigating this emerging disease.
Publications
- Melzer, M.J., Sugano, J.S., Cabanas, D., Dey, K., Kandouh, B., Mauro, D., Rushanaedy, I., Srivastava, S., Watanabe, S., Borth, W.B., Tripathi, S., Mastsumoto, T., Keith, L., Gonsalves, D., and Hu, J.S. (2012). First Report of Pepper Mottle Virus on Tomato in Hawaii. Plant Disease 96:917.
- Wang, I.C., Dey, K., Sether, D., Borth, W., Melzer, M., and Hu, J.S. (2012). Banana Bract Mosaic Virus in Flowering Ginger in Hawaii. Phytopathology 132:131.
- Ma, H., Song, C.F., Borth, W., Sether, D., Melzer, M., and Hu, J.S. (2011). Modified Expression of Alternative Oxidase in Transgenic Plants Affects Tomato Spotted Wilt Virus Resistance. BMC Biotechnology 11:96
- Melzer, M.J., Sether, D.M., Borth, W.B., and Hu, J.S. (2012). Characterization of a Virus Infecting Citrus volkameriana (Ten. & Pasq.) with Citrus 2 leprosis-like Symptoms. Phytopathology 102: 122-127.
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Progress 09/01/10 to 08/31/11
Outputs
OUTPUTS: Anthurium (Anthurium spp.) growers in Hawaii have reported a serious new disease affecting anthurium with symptoms that include leaf mosaic and scalloping, vein chlorosis and necrosis, plant stunting, and flower deformities that render the flowers unmarketable. Our preliminary isolations and sequence analyses have shown that a Chrysovirus-like pathogen is associated with the diseased plants. This is the first report of Chrysoviruses that possibly cause infection in flowering plants and have the potential to seriously impact the production of this important horticultural commodity. To date, five different anthurium cultivars have been afflicted by this disease, although nothing is known about the potential vectors of the pathogen. There are also diseases of other culturally and economically important crops that have become more prevalent in the last few years in Hawaii. Hawaiian ti (Cordyline fruticosa) is afflicted by a disease characterized by ringspots that are very similar to foliar symptoms caused by viruses in other host plants. Symptomatic plants have been found on Maui, the Big Island, and Oahu, where the green variety, not other varieties of ti are afflicted with this disorder. We have found at least four distinct closteroviruses from green ti varieties with ringspot symptoms, but have not determined which of these may be associated with symptom expression in infected plants. Hawaiian Ti is exclusively propagated by vegetative cuttings; therefore virus spread within cuttings of these cultivars is almost certain. In addition, there is the probability that other, as yet uncharacterized closteroviruses, or other types of plant viruses, exist in these plants. PARTICIPANTS: Principal Investigators: Paul Singleton, University of Hawaii, College of Tropical Agriculture and Human Resources (CTAHR). John Hu, University of Hawaii, CTAHR. Diane Sether, University of Hawaii, CTAHR. Michael Melzer, University of Hawaii, CTAHR. Robert Paull, University of Hawaii, CTAHR. Tessie Amore, University of Hawaii, CTAHR. Joanne Licthy, University of Hawaii, CTAHR. Janice Uchida, University of Hawaii, CTAHR. David Christopher, University of Hawaii, CTAHR. Kent Kobayashi, University of Hawaii, CTAHR. Partner Organization: Judy Zhu, Hawaii Agriculture Research Center. TARGET AUDIENCES: Hawaii Anthurium Industry Association, Hawaii Tropical Flower Council, Hawaii Florists and Shippers Association, Big Island Association of Nurserymen, Orchid Growers of Hawaii, Hawaii Tropical Flower and Foliage Association, Protea Growers Association of Hawaii. Information is disseminated through yearly review meetings which include progress reports, site visits, and laboratory tours presented by the principal investigators listed above. PROJECT MODIFICATIONS: Not relevant to this project.
Impacts
Anthurium mosaic disease is a new disease of anthurium that has severely affected at least five important varieties in Hawaii. Our main objective includes characterizing the virus, associated with symptomatic anthurium, putatively called Anthurium mosaic associated virus (AMaV), developing publicly accessible detection assays, determining the disease's etiology, mode of spread, distribution throughout the Hawaiian Islands, and evaluating the resistance or susceptibility of other important anthurium varieties. These objectives will provide the knowledge needed to develop management strategies for the disease and to minimize the effect of this disease. Our progress in the first three months of this project includes characterizing the complete sequence of AMaV from double-stranded RNAs isolated from symptomatic anthurium plants. Characterization of AMaV, shows the virus to be most similar to members of the Chrysovirus family, which is comprised of mycoviruses which are viruses that infect fungi. We have determined the complete virus sequences and submitted the sequences to GenBank, an internationally accessible sequence repository. We have also developed a detection assay for AMaV and established public access to our AMaV detection assays through the University of Hawaii at Manoa Agricultural Disease Diagnostic Service Center to assist growers and stakeholders in evaluating their material for presence of the virus. We have also purified the virus and evaluated the size of the proteins with protein electrophoresis. This information and our planned future work will be used to achieve our objective so that we may establish the best management practices for the disease. Optimum postharvest handling is essential to maintain the quality and to prolong the vase life of cut flowers and foliage. The market for tropical flowers and foliage is very competitive and it is necessary to continuously review product mix, product quality and postharvest procedures. Research on postharvest cut flower and hydration solutions and vase solutions were carried out nearly 20 years ago and new varieties are now being grown. These postharvest treatments need to be reevaluated and recommendations updated. This proposal's final goal was to evaluate new postharvest treatment to maintain quality and extend the vase life of Hawaii's cut flowers and foliage. The data from this comparison can be used to expand Hawaii's competitive advantages and develop newer competitive niches.
Publications
- Melzer, M.J., Ogata, D., Fukuda, S.K., Shimabuku, R, Borth, W.B., Sether, D. M., and Hu, J.S. (2010). First Report of Tomato Yellow Leaf Curl Virus in Hawaii. Plant Dis. 94:641.
- Sether, D. M., Borth, W.B., Shimabuku, R.S., Pappu, H.R., Melzer, M.J. and Hu, J.S. (2010). First Report of Iris Yellow Spot Virus in Onion in Hawaii. Plant Dis. 94:1508.
- Wang, I.C., Sether, D.M., Melzer, M.J., Borth, W.B., and Hu, J.S. (2010). First Report of Banana bract mosaic virus in Flowering Ginger, Alpinia purpurata, in Hawaii. Plant Dis. 94:921.
- Kobayashi, K.D., and Amore, T.D. (2010). Use of Light-emitting Diodes in Anthurium and Orchid Mircopropagation (abstract). HortScience 45(8):S194.
- Melzer, M. J., Sether, D.M., Borth, W.B., Mersino, E.F., and Hu, J.S. (2011). An Assemblage of Closteroviruses Infects Hawaiian ti (Cordyline fruticosa L.). Virus Genes 42:254-260.
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