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United States Department of Agriculture

Agricultural Research Service

Related Topics

Research Project: CONSERVATION AND CHARACTERIZATION OF GERMPLASM OF SELECTED VEGETABLE CROPS

Location: Plant Genetic Resources Research

2012 Annual Report


1a. Objectives (from AD-416):
1. Strategically expand the genetic diversity in genebank collections and improve associated information for priority buckwheat, tomato, cole crops, bulb and bunching onions, and other specialty vegetable crops (celery, radish, asparagus, winter squash, and tomatillo) and their wild relatives. 2. Conserve and regenerate priority buckwheat, tomato, cole crop, bulb and bunching onion, and other specialty vegetable crop (celery, radish, asparagus, winter squash, and tomatillo) genetic resources efficiently and effectively, and distribute pathogen-tested samples (whenever feasible) and associated information worldwide. 3. Strategically characterize (“genotype”) and evaluate (“phenotype”) priority buckwheat, tomato, cole crop, bulb and bunching onion, and other specialty vegetable crop (celery, radish, asparagus, winter squash, tomatillo) genetic resources for molecular markers and highly heritable horticultural and morphological traits.


1b. Approach (from AD-416):
The objectives of this project will be met by a) expanding the genetic diversity in genebank collections and improving associated information for priority buckwheat, tomato, cole crops, bulb and bunching onions, and other specialty vegetable crops (celery, radish, asparagus, winter squash, and tomatillo) and their wild relatives, b) conserving and regenerating genetic resources of these taxa efficiently and effectively, and distributing pathogen-tested samples (whenever feasible) and associated information worldwide, and c) characterizing (“genotype”) and evaluating (“phenotype”) genetic resources of these taxa for molecular markers and highly heritable horticultural and morphological traits. In the next five years the major activities of the project will emphasize upgrading standards for viability and number of seed stored in the active and base collections. Characterization for minimal descriptor lists will be completed for tomatoes, Crucifers, and onions. The primary link with users will be through Crop Germplasm Committees that define crop priorities for collection and evaluation.


3. Progress Report:
In addition to standard characterization, 52 tomato lines representing varieties from five different decades as determined by dates for Plant Variety Protection Certificates were grown in Geneva, NY in 2011 for evaluation. These accessions were evaluated for fruit nutritional traits and morphology. In addition, we collaborated with Research Chemist (USDA-ARS) for performing high performance liquid chromatography of fruit samples which will be used for identification and measurement of nitrogen-containing metabolites. These compounds regulate chemical processes and influence fruit ripening and fruit quality in various crops and are an important class of natural products that contribute to quality and utilization and include essential nutrients that can influence mood and mental well-being. Data from the two years will be analyzed in the upcoming fiscal year. Inferior flavor is one of the most commonly heard complaints associated with modern varieties of tomato. In collaboration with North Carolina State University 173 accessions from the PGRU tomato core collection were evaluated for odor, taste, flavor, texture and related components including soluble solids and titratable acidity. Overall flavor was analyzed with respect to other traits including fruit firmness, color parameters, lycopene and vitamin C. Information obtained from this study will be useful for tomato breeders aiming to improve tomato flavor. Tomatillo has been rising in consumption in the U.S. with increased influence of Mexican and Latin American cuisines. Very few molecular genetic or genomic resources have been developed for this crop. We resequenced 14 tomato markers (gene fragments) in five inbred lines of PGRU tomatillo accessions. We found a moderate degree of transferability of markers between tomato and tomatillo. We are now working on optimizing next-generation sequence based markers (genotyping by sequencing, GBS) tomato and tomatillo Wild tomato Lycopersicon peruvianum has been reclassified into four new Solanum spp. taxa. We have isolated DNA from 12 PGRU accessions of each of the four species. We are now working on optimizing and applying GBS to these DNA samples. Data will be used to estimate diversity and gene flow within and among species, and to develop species diagnostic markers.


4. Accomplishments


Review Publications
Panthee, D., Cao, C., Debenport, S., Rodriguez, G., Labate, J.A., Robertson, L.D., Breksa Iii, A.P., Van Der Knaap, E., Mcspadden-Gardener, B. 2012. Magnitude of genotype x environment interactions affecting tomato fruit quality. HortScience. 47:721-726.

Last Modified: 10/19/2017
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