2005 Annual Report 4d.Progress report. This report serves to document research conducted under a Specific Cooperative agreement between ARS and the University of Hawaii. Additional details of research can be found in the report of the associated in-house project 5320-21000-010-00D, Genomic and Biotechnological Approaches for Evaluating and Improving Tropical Crops. There are three subprojects as part of this project. Dr. John Hu, Department of Plant and Environmental Protection Sciences (PEPS); Drs. Mark Wright and Rodrigo Almeida, PEPS; and Drs. Scot Nelson (Hilo) and Stephen Ferreira, PEPS. Wright and Almeida Project: Sampling plan of banana aphid: Finalizing surveys needed for the development of a sampling plan for banana aphid; data analysis has been started. The sampling plan will provide growers with the information on how to best sample for the presence of the banana aphids. Within plant distribution of banana aphids: In spite of the conventional wisdom that the banana aphid is found only on the "cigar" leaves - whole plant surveys have shown that the lower leaf bracts of plants more accurately indicate the presence or absence of aphid infestation on individual banana suckers. Sampling the cigar leaf provides false negatives for the presence of the aphid in approximately 50% of the cases. These results will be incorporated into the sampling plan. Imidacloprid efficiency and persistence: The first laboratory trial examining the efficiency and persistency of imidacloprid on banana aphid mortality has been completed. Additional replications in the lab and the field are underway. Survey of BBTV spread in commercial plantations: Initial plan was to survey four commercial plantations for temporal and spatial distribution of BBTV symptomatic plants using GPS units. One of the cooperating farmers stop growing bananas and another discontinued his involvement. Thus, only two farmers are collaborating with us. Fortunately, they are among the largest growers on Oahu and will provide valuable data to study BBTV epidemiology. Since January 2005, monthly data from these two farms have been collected. Disease development under field conditions: The first replicate has been finalized and a second started on our field plots to determine how long it takes for BBTV symptoms to appear in bananas after they have been inoculated with aphids. Other information collected are the location on the plant of the first symptoms and if there are phenological and physiological characteristics that change in symptomatic plants prior to obvious symptoms. Besides detailed measurements on plant growth parameters, other data obtained include leaf chlorophyll content and virus detection from plants over time using PCR methodology. Aphid biology: We are conducting experiments to determine aphid fecundity, longevity and length of nymphal stage. Data will be used to develop models for population growth at different temperatures. Aphid transmission of BBTV: Experiments continue to study aphid transmission of BBTV, testing different systems to maximize aphid efficiency in the laboratory as a basis for future studies. BBTV genetic diversity: The genetic diversity of BBTV in Hawaii is being studied using primers for the 6 components of the virus. Thus far, 15 isolates from Oahu are being analyzed for all components and samples from the other islands will commence in the second year of the project. These data should provide information about the genetic diversity of the BBTV in Hawaii, how it has spread throughout Hawaii and potentially the number of different introductions of BBTV from other locations. This could assist in the development of interisland quarantine practices for pests limited to one or a few islands. John Hu project: Real time PCR: A real time PCR system has been established to detect BBTV from infected banana plants. Plant sample preparation methods and various BBTV-specific primers were obtained and examined to optimize the system. Real time PCR is more sensitive than regular PCR or ELISA assays for BBTV. There is potential for testing hundreds of banana samples. In the next year of the project, with the completion of the real time PCR for BBTV, it will be used to detect BBTV from a large number of samples and to identify BBTV infection from symptomless banana plants. Citrus Tristeza: Optimization of the Agrobacterium tumefaciens-mediated transformation of Mexican lime was conducted using the GUS reporter gene. In the upcoming year, a real time PCR system will be developed to detect CTV infection and various CTV gene constructs will be used to transform Mexican lime to produce CTV-resistant plants. Nelson and Ferreira project: Banana Action Group: A multi-agency team, named the Banana Action Group (BAG), was created to coordinate statewide research and extension activities for BBTV in Hawaii. BAG has members from the University of Hawaii (Manoa and Hilo campuses); the Hawaii Department of Agriculture; Hawaii Banana Industry Association; Bayer Crop Science; Maui Invasive Species Committee and the USDA-ARS Pacific Basin Agricultural Research Center. BAG members provided information for a series of local newspaper and magazine articles about BBTV, published in Hawaii in 2004 and 2005. A number of BBTV extension type publications were produced including articles, brochures, flyers, a scouting guide and posters. A slide presentation about BBTV for use by agents and clients was created and posted on the World Wide Web. Two complete websites devoted to BBTV were created and placed on the UH-CTAHR server and the University of Hawaii ITS server. These websites are the most comprehensive sites about BBTV that are available on the worldwide web, and include detailed information on disease symptoms, occurrence, and management. We also supported the Maui Invasive Species Committee and provided photographs, information and dollars to support their BBTV publications for Maui. A complete set of BBTV photographs of all kinds were assembled and copied onto CDs for distribution to interested persons or agencies. Farmer education and training activities are ongoing; field visits were made to train farmers and to scout for diseased plants. A number of phone calls from clients were received and advice and diagnosis given as needed. As new information is gleaned from research, application will be transferred to banana growers through websites; articles, and presentations at grower meetings. Publications/Presentations/Websites: Publications Wright, M.G., Hooks, C.R.R. and Robson, J.D. 2005 Aphids and banana bunchy top virus in Hawaii. Proceedings of the Hawaiian Entomological Society. Submitted. Nelson, S., Ploetz, R., and Kepler, A. (2005). Musa sp. (banana), Traditional Tree Initiative - Species Profiles for Pacific Island Agroforestry. Craig Elevitch, ed. Permanent Agriculture Resources, Holualoa, HI. (in press). Banana Bunchy Top Websites (2): http://www.ctahr.hawaii.edu/banana http://www2.hawaii.edu/~banana Educational PDF files (8): (1) BBTV Disease Symptoms and Management brochure http://www.ctahr.hawaii.edu/banana/downloads/brochure1.pdf (2) Banana Bunchy Top: Detailed Signs and Symptoms http://www.ctahr.hawaii.edu/banana/downloads/BBTV-details.pdf (3) Banana Bunchy Top Virus - Symptoms and Management http://www.ctahr.hawaii.edu/banana/downloads/BBTV1.pdf (4) Banana Bunchy Top Poster http://www.ctahr.hawaii.edu/banana/downloads/poster1a.pdf (5) Banana Bunchy Top Poster http://www.ctahr.hawaii.edu/banana/downloads/poster1a.pdfhttp://www.ctahr.hawaii.edu/banana/downloads/poster1a.pdf (6) Banana bunchy top disease (with Maui Invasive Species Committee) http://www.ctahr.hawaii.edu/banana/downloads/MISC%20Handout.pdf (7) BBTV Trifold brochure (with Maui Invasive Species Committee) http://www.ctahr.hawaii.edu/banana/downloads/MISCbrochure.pdf (8) BBTV Molokai and Lanai flier (with Maui Invasive Species Committee) http://www.ctahr.hawaii.edu/banana/downloads/MOLOKAILANAI.pdf Internet Slide Show (Powerpoint) (1): http://www.ctahr.hawaii.edu/banana/b2_files/frame.htm Maps of bunchy top distribution in Hawaii (1): http://www.ctahr.hawaii.edu/banana/maps.asp