2011 Annual Report
Objective 1: Strategically expand the genetic diversity in genebank collections and improve associated information for priority vine, tree fruit, and nut crops (and their wild relatives) adapted to Mediterranean-like climates. Sub-objectives: a. Acquire samples of Vitis, Prunus, Juglans, Pistacia, and Punica from Turkey and the Caucasus nations to fill current gaps in NPGS collections of these priority genera. b. Survey existing U. S. domestic (California and other states) collections of priority crops, identify material that would fill gaps in NPGS collections, and begin acquiring and characterizing them, initially emphasizing Vitis, Prunus, and Ficus cultivated material and germplasm of related wild species.
Objective 2: Conserve and regenerate priority vine, tree fruit, and nut crop genetic resources adapted to Mediterranean-like climates efficiently and effectively, and distribute disease-free samples (whenever feasible) and associated information worldwide. Sub-objectives: a. Conserve, regenerate, and distribute vine, tree fruit, and nut genetic resources and associated information, emphasizing Vitis, Prunus, Juglans, Ficus, Olea, and Punica. b. Backup primary collections of Vitis, Prunus, Juglans, Ficus, and Olea, via high-density nurseries, cryopreservation, and tissue culture. c. In collaboration with University of California, Davis Foundation Plant Services and the Canadian Plant Germplasm System, process 70 accessions of NPGS warm-season grapes through quarantine and make them available for distribution.
Objective 3: Strategically characterize (“genotype”) and evaluate (“phenotype”) priority vine, tree fruit, and nut crop genetic resources adapted to Mediterranean-like climates for molecular markers and key horticultural traits such as adaptation and product quality. Sub-objectives: a. In cooperation with other ARS and university collaborators, develop and apply new genetic markers for phylogenetic and genetic diversity analyses of priority crops, emphasizing simple sequence repeat (SSR) in Vitis, Prunus, Juglans, Ficus, Olea, and Pistacia. b. Generate SSR “fingerprints” for ca. 1,000 accessions of priority crops, emphasizing Vitis, Prunus, Juglans, Ficus, Olea, and Pistacia, and use them to determine the identity, diversity, and systematic relationships of these genetic resources, and to enhance the effectiveness of genetic resource management. Incorporate characterization data into GRIN and/or other databases. c. Extend ongoing cooperative research to evaluate horticultural quality for ca. 1,000 accessions of Vitis, Prunus, Juglans, Ficus, Olea, and Pistacia, and incorporate phenotypic data into GRIN and/or other databases.
Peach and almond data updated recently are being analyzed to quantify and describe genetic diversity and differentiation within and between the collections. Five diverse almond genotypes along with five wild almond accessions will be sequenced and combined with peach sequences developed in a different UC collaborator’s project for SNP discovery. The SNPs will be in mapping genes conferring resistance to soil borne diseases in a Prunus rootstock development project. We have examined the possibility of using tetra-nucleotide repeat microsatellite loci to genotype olive collections. Out of a dozen loci tried, seven amplified but showed low polymorphism.
In the walnut industry/UC Discovery funded project we have phenotyped the entire NCGR collection Juglans regia for two years and the data are being tabulated for use in association analysis.
In collaboration with the Crops Pathology and Genetics Group, characterization of wild Juglans to identify novel sources of resistance to soil borne diseases is continuing. So far a number of J. microcarpa, J. major, J. hindsii, and one J. cathayensis accessions have shown promising levels of tolerance to crowngall, Phytophthora spp., and/or lesion nematodes. They are being crossed with J. regia to produce interspecific hybrids to test them for commercial exploitation as new rootstocks. To date, more than 300 hybrids have been put into ovule culture to clonally propagate them for further testing and establishment of field trials.
The Actinida (kiwifruit) collection has been re-consolidated in Davis. Because of concern about how the cold hardy kiwifruit would survive in Davis, the cold-hardy kiwifurit collection was moved to the Corvallis genebank. The remaining backup plants in Davis have grown well with no problems. The Corvallis site will become the backup site for the hardy kiwifruit.
Preece, J.E. 2011. Micropropagation in stationay liquid media. Propagation of Ornamental Plants. 10(4):183-187.
Pitcher, A.M., Aradhya, M.K., Soleri, D., Smith, J.L., Polito, V.S. 2010. Molecular characterization of genetic diversity, structure, and differentiation in the olive (Olea europaea L.) germplasm collection of the united states department of agriculture. Genetic Resources and Crop Evolution. 58:519-539.
Gunn, B.F., Aradhya, M.K., Salick, J.M., Miller, A.J., Yongping, Y., Lin, L. 2010. Genetic variation in walnuts (Juglans regia and J. sigillata; Juglandaceae): Species distinctions, human impacts, and the conservation of agrobiodiversity in Yunnan, China1 . American Journal of Botany 97:660-671.
Ibrahimovi, Z., Mcgranahan, G.H., Leslie, C.A., Aradhya, M.K. 2010. Genetic diversity in walnut (Juglans regia) from the caucasus nation of Azerbaijan. Acta Horticulturae. 861:163-170.
Aradhya, M.K., Woeste, K., Velasco, D. 2010. Genetic Diversity, Structure and Differentiation in Cultivated Walnut (Juglans regia L.). Acta Horticulturae. 861:127-132.
Myles, S., Boyko, A., Owens, C.L., Brown, P., Fabrizio, G., Aradhya, M.K., Prins, B.H., Reynolds, A., Chia, J., Ware, D., Bustamante, C., Buckler IV, E.S. 2011. Genetic structure and domestication history of the grape. Proceedings of the National Academy of Sciences. 10.1073/pnas.1009363108.