Development of Segregating Populations for Molecular and Genetic Analyses of X-Disease in Chokecherry (Prunus virginiana L.)


NRI Award #2005-35300-15457
PI: Wenhao (David) Dai, Co-PI: James A. Walla
Department of Plant Sciences and Department of Plant Pathology
North Dakota State University, Fargo, ND 58105
E-mail: wenhao.dai@ndsu.edu
Telephone: 701-231-8473


Accomplishments:
  • Four hybrid populations have been developed by hybridizing disease resistant and susceptible chokecherry lines selected from a large and well-evaluated chokecherry germplasm collection.
  • The 2005 population is being tested for X-disease resistance. Using a side grafting method, two scions were grafted on the main stem of each plant. All scions survived at least two weeks after grafting, allowing adequate time for transmission of X-disease phytoplasmas from the scion to the plant (rootstock).
  • Nested-PCR was used for early confirmation of the infection and proliferation of X-disease phytoplasmas in inoculated chokecherry plants. X-disease phytoplasmas were detected in the second week after graft inoculation.
  • Preliminary phenotyping of the segregation population for X-disease resistance has been attempted based on X-disease symptom.
  • Hybrid seeds from the other crosses are currently under stratification treatment and will be sowed out and grown in the greenhouse in the Spring of 2008.
  • Chromosome analysis confirmed that Prunus virginiana is a tetraploid and will be a unique Prunus species for genetic research.
  • Molecular marker analysis for chokecherry species, such as RAPD and SSR, have been attempted to develop reliable strategies of identifying molecular markers linked to X-disease resistance.
  • A genetic transformation system of chokecherry has been developed, which can be used to test X-disease resistant genes in the future.
Broad Impacts:

X-disease and other phytoplasma-associated diseases are devastating to many high value cash crops and forest trees, such as stone fruits, vegetables, ornamentals, and plantation trees, causing billions of dollars of damage each year, yet there is no effective control method for any of these diseases. The purpose of this project is to develop a well-designed segregating population of chokecherry used to identify molecular markers linked to X-disease resistance genes. Therefore, the success of this project will assist us to understand host/pathogen interactions and genetics of resistance genes in chokecherry, and to develop effective methods of managing X-disease or other phytoplasma-associated diseases.

Deliverables
  • Publications:
  • Dai, W., V. Magnusson, and C. Johnson. 2007. Agrobacterium-mediated transformation of chokecherry (Prunus virginiana L.). HortScience 41: 140-142. 105.
  • Meeting Abstracts:
  • Development of Segregating Populations for Molecular and Genetic Analyses of X-Disease Resistance in Chokecherry (Prunus Virginiana L.). PAG conference, 2007.
  • Identification of Molecular Markers Linked to X-Disease Resistance in Chokecherry (Prunus virginiana L.): Inoculation, Verification and Early Screening. PAG conference, 2008.
  • Community resources generated (sequences, populations, plant materials)
  • Four chokecherry segregating populations have been generated. Another research project will be carried out using the resource of this project: Breeding Elite Chokecherry Cultivars for Small Fruit Production in North Dakota.
  • Training:
  • Undergraduates:
    • Sarah Gegne
    • Karissa Rothmeire
    • John Stenger
  • Graduates:
    • Vicki Magnussion
    • Andrea Swanberg
    • Hongxia Wang
    • Ben Su

Collaborations:

This project is a collaborative effort in the multidisciplinary research field including plant molecular biology, plant pathology, plant genetics, and biotechnology.

Additional collaborators: Dr. J. Hu, Plant Molecular Genetics, USDA-ARS in Fargo, ND; Dr. C.C. Jan, Plant Cytogenetics, USDA-ARS in Fargo, ND.