2008 Annual Report
1a.Objectives (from AD-416)
To collect, maintain and preserve diversity of tropical fruit and nut crops and potential beverage, ornamental and vegetable germplasm. To identify, evaluate and characterize horticultural traits and responses to environment, disease and pest stresses; to improve long-term seed and in vitro storage techniques; to evaluate germplasm propagation and production systems to minimize chemical dependence and maximize crop yield, quality, value, and production consistency. Data input into GRIN database. The funding being redirected in this project will be used to enhance research on the following objective: Efficiently and effectively conserve and regenerate tropical fruit genetic resources, and distribute pathogen-tested samples and associated information worldwide.
1b.Approach (from AD-416)
Germplasm collection to be expanded through active exploration & exchanges, priorities are elite traits and species diversity. Collection maintained in field arboreta with in vitro storage for selected specimens. Germplasm collection is information driven, accessions are to be evaluated and characterized by a team of horticulturists and pathologists for horticultural qualities, responses to pests, diseases and environmental stresses using standard horticultural, plant pathology & molecular methods. Cooperative research and support with NPGS germplasm sites. Evaluation information input into GRIN database..
2)Identify physiological and cultural components of growth and development in selected tropical fruit, ornamental and vegetable crops, and to develop systems approaches to manage timing and reliability in flower and fruit production..
3)Enhance tropical crop germplasm through selection and hybridization..
4)Develop management strategies for control of tropical plant diseases on selected germplasm.
This unit supports NP 301 Plant Genetic Resources, Genomics and Genetic Improvement, Component 1: Plant and Microbial Genetic Resource Management, Problem Statement 1A: Efficiently and effectively manage plant and microbial genetic resources, and Problem Statement 1B: Assess the systematic relationships and genetic diversity of crop genetic resources; and Component 3: Genetic Improvement of Crops, Problem Statement 3C: Germplasm enhancement/release of improved genetic resources and varieties. The mission of the unit is to collect, maintain, preserve, evaluate, distribute and secure the integrity and diversity of designated tropical fruit, nut and beverage germplasm. We provided long-term maintenance of 14 designated tropical fruit & nut crops totaling 1000 accessions in 33 acres of field plantings, in greenhouses, tissue culture and as seed storage. The unit provides plant germplasm for scientific research nationally and internationally. In the past five years, distributions were 502 orders for 1752 items; introductions were 129 with 36 foreign and 93 domestic. Photo, observation and morphological records (2378) were collected for pineapple, peach palm, papaya, litchi, rambutan, guava, Lansium, mangosteen, starfruit, longan, breadfruit, pili nut and Malpighia. Flowering data collected for 83 accessions of litchi and 67 accessions of guava. Total GRIN (Germplasm Resource Information Network) accessions are 683; loaded GRIN records including 178 cooperators, 447 orders, 1481 order items, 5462 observations, 58 accession records, 60 inventory, 302 voucher and 297 citations. Other projects completed include molecular characterization of papaya and macadamia accessions; established regeneration techniques for bacteria wilt-free rhizome for ginger; production and management practice for ‘Kaimana’ litchi; demonstrated production of southern highbush blueberry in Hawaii; developed propagation and cultivation techniques for Vaccinium reticulatum ('Ohelo); established pathogen identification and management for rambutan, macadamia, and guava, and developed a leaf bioassay for rapid disease identification in guava and rambutan. A lease agreement with the Hamakua/North Hilo Agricultural Cooperative in Paauilo provided a Papaya Ringspot Virus (PRSV) free environment for the regeneration of 26 accessions of papaya germplasm. Unit scientist visited the National Center for Genetic Resources Preservation for training in cryopreservation of papaya, macadamia and canarium seeds. Collections of pineapple, Vasconcellea, breadfruit and tea have been established in tissue culture. Additional research initiatives include:.
1)an on-farm testing of pre-harvest disease management effects on post-harvest fruit quality in rambutan and longan;.
2)a screening protocol for bacterial blight disease resistance for 709 lines of transgenic anthurium;.
3)a protocol was developed for chemical management of Macadamia Quick Decline disease;.
4)an investigation into biotechnological management of the Precocious Natural Flowering (PNF) and nematode resistance in pineapple.
Propagation and cultivation of 'Ohelo. The collection and conservation of a wild relative of the blueberry in our own backyard (Hawaii), will reduce the wild harvest pressure on ‘ohelo and minimize damage to the natural habitat. ARS scientists at the Pacific Basin Agricultural Research Center in Hilo, HI successfully developed procedures for domestication using seed, tissue culture and vegetative propagation by cuttings, and we demonstrated successful field planting of our seedlings at the experimental plot. We identified three selections among 200 seedlings with excellent ornamental potential, and others for berry production. We will continue our investigation of this unique Vaccinium germplasm in Hawaii with our partners at the Corvallis repository. Contributing to NP 301 Component 3: Genetic Improvement of Crops, Problem Statement 3C: Germplasm enhancement/release of improved genetic resources and varieties.
Pestalotiopsis fruit rot on rambutan in Hawaii. Rambutan fruit is an important local product that has developed a fungal disease identified by dark brown-to-black spots on mature fruit and blackened areas at the base of spinterns (hair-like projections)of mature and immature fruits. The fungus was identified by ARS scientists at the Pacific Basin Agricultural Research Center in Hilo, HI as Pestalotiopsis virgatula (Kleb.) Stey because of conidial and cultural characteristics and confirmed by molecular analysis of the 5.8S subunit and flanking internal transcribed spacers (ITS1 and ITS2) of rDNA amplified from DNA extracted from single-spore cultures with the ITS1/ITS4 primers. Pathogenicity was confirmed by completing Koch’s postulates. This is the first report of P. virgatula causing fruit spots on rambutan in Hawaii. This data provides useful insights into the etiology of this disease and the pre-harvest damage resulting in crop loss caused by this fungus. This data also provides the basis to evaluate control measures of this pathogen under field conditions. Contributing to NP 301 Component 1: Plant and Microbial Genetic Resource Management, Problem Statement 1A: Efficiently and effectively manage plant and microbial genetic resources.
First report of Dolabra nepheliae on rambutan and litchi in Hawaii and Puerto Rico. A stem canker disease on rambutan (Nephelium lappaceum L.)and litchi (Litchi chinensis Sonn.) was identified in plants in Hawaii and Puerto Rico. A fungus associated with the cankers was identified by ARS scientists in the Pacific Basin Tropical Plant Genetic Resource Unit in Hilo, HI as Dolabra nepheliae C. Booth & Ting. Specimens have been deposited at the U.S. National Fungus Collections (Hawaii on Nephelium BPI 878189, Puerto Rico (PR) on Nephelium BPI 878188, and PR on Litchi BPI 878190). This fungus was not known on Nephelium spp. in Hawaii and was not previously known from Puerto Rico on either host. Contributing to NP 301 Component 1: Plant and Microbial Genetic Resource Management, Problem Statement 1A: Efficiently and effectively manage plant and microbial genetic resources.
Atypical internal yellowing of papaya fruit in Hawaii. ARS scientists in the Pacific Basin Tropical Plant Genetic Resource Unit in Hilo, HI reported the formation of atypical internal yellowing in ripe papaya caused by the bacterium Enterobacter sakazakii. Unique symptoms were identified and described and included a dull, greenish yellow discoloration of the flesh with a distinct margin extending from the seed cavity into the pericarp, along with a pungent odor. Although less prevalent (1% incidence)than the typical internal yellowing produced by E. cloacae, E. sakazakii has the potential to affect quality and food safety of fresh and processed papaya products. E. sakazakii has been implicated in a severe form of neonatal meningitis, sepsis, and necrotizing enterocolitis indicating that E. sakazakii is a cross-domain pathogen. These findings are particularly applicable to farmers and processors interested in providing papaya products by indicating the potential danger of having a cross-domain pathogen present in the product. Contributing to NP 301 Component 1: Plant and Microbial Genetic Resource Management, Problem Statement 1A: Efficiently and effectively manage palnt and microbial genetic resources.
Production of Southern Highbush blueberries in Hawaii. There is a need for additional crop development in Hawaii to help suppost the regional economy. A cooperative project with the National Clonal Germplasm Repository in Corvallis, Oregon and the ARS scientists at the Pacific Basin Agricultural Research Center in Hilo, HI was established to evaluate growth and production potential of selected blueberry varieties as a high value niche market crop for Hawaii agriculture diversification, The six clones performed very satisfactory after we customized the field management practices and have created much excitement as a high value niche market crop for Hawaii. The project has been adopted and expanded by the University of Hawaii, CTAHR in 2007. Contributing to NP 301 Component 1: Plant and Microbial Genetic Resource Management, Problem Statement 1A: Efficiently and effectively manage plant and microbial genetic resources.
5.Significant Activities that Support Special Target Populations
The blueberry projects provided new ideas and potential new crops for small farms in Hawaii. Hawaii agriculture can compete in the world market with unique, signature products of high quality and value.
To provide farmers with information on getting consistent fruit crops, the ‘Kaimana’ litchi management protocol developed at the unit was expanded to different climacteric locations on the Big Island of Hawaii. Here the management practices are being optimized for each location. In addition, alternatives to potassium chlorate and updates on the mechanism of potassium chlorate induced flowering were also presented to the Hawaii Tropical Fruit Growers Association at their yearly conference.
Research on improving the inflorescence emergence in Miltoniopsis with GA3 was presented to the Hawaii Orchid Growers during their conference in 2007.
On September 27, 2007 a talk was given to the Hawaii Tropical Fruit Growers on research to determine the incidence and etiology of infection of rambutan by fungal pathogens. On October 17, 2007 research findings on Macadamia Tree Quick Decline (MQD) and field management strategies to alleviate the problem were presented to the Hawaii Farm Bureau. On May 14, 2008 a talk was given to members of the Hawaii Anthurium growers association on the progress of the screening tests of transgenic anthurium against bacterial blight. On June 26, 2008 a talk was given to the Pacific Division of the American Phytopathological Society in Jackson Hole, WY on strategies for controlling macadamia quick decline.
|Number of Web Sites Managed||1|
|Number of Non-Peer Reviewed Presentations and Proceedings||5|
|Number of Newspaper Articles and Other Presentations for Non-Science Audiences||2|
Hummer, K.E., Zee, F.T., Strauss, A.J., Keith, L.M., Nishijima, W. 2007. Evergreen Production of Southern Highbush Blueberries in Hawaii. Journal of American Pomological Society. 61(4):188-195.
Keith, R.C., K.A. Nishijima, L.M. Keith, M.M. Fitch, W.T. Nishijima, M.M. Wall. 2008. Atypical internal yellowing of papaya fruit in Hawaii caused by Enterobacter sakazakii. Plant Disease. 92:487.
Rossman, A.Y., Goenaga, R.J., Keith, L.M. 2007. First report of Dolabra nepheliae on rambutan and litchi in Hawaii and Puerto Rico. Plant Disease. 91:1685.
Keith, L.M. 2008. First report of Pestalotiopsis virgatula on rambutan in Hawaii. Plant Disease 92(5):835.