PRINCIPLES AND PRACTICES FOR IMPROVING ORGANIC FARMING IN THE MID-ATLANTIC REGION
Location: Sustainable Agricultural Systems Laboratory
Title: Evaluating a core germplasm collection of the cover crop hairy vetch for use in sustainable farming systems
Submitted to: Crop Science
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: January 25, 2011
Publication Date: August 11, 2011
Citation: Maul, J.E., Mirsky, S.B., Emche, S.E., Devine, T.E. 2011. Evaluating a core germplasm collection of the cover crop hairy vetch for use in sustainable farming systems. Crop Science. 51:2615-2625.
Interpretive Summary: Plants exhibit a wide variety of traits that are based on the underlying composition of their genomes. The interaction of genomic composition and the environment in which a plant is growing can determine the expression of desirable or undesirable traits. In many cases when researchers or farmers are exploring a new or undeveloped crop species the genetic composition of the species is unknown and researchers and farmers may have to rely solely on observation of the expressed trait of interest. This approach, while very successful in the long-term, may require a very large starting population if a concerted breeding effort is planned for development of useful crop varieties. On the other hand breeding approaches that combine an understanding of genetic composition and trait expression tend to be much more efficient in terms of resource use and the time it takes to develop a new stable variety of the crop species of interest. In this report we define a core germplasm collection of the cover crop hairy vetch (Vicia villosa). We do this by using molecular techniques to determine the underlying genetic composition of 64 accessions of hairy vetch available from the USDA National Plant Germplasm System (NPGS). We are able to rank all 64 accession based on their genetic relatedness and from this ranking choose selected accessions that cover the breadth of diversity in the NPGS collection. The selected accessions make up a "core genetic subset" of the germplasm collection that can be used by researchers and farmers in future research programs. By defining a "core genetic subset" of the USDA NPGS hairy vetch collection we provide a tool for breeders to use during experimental design phases of future hairy vetch breeding programs. Breeders will be able to select a reduced set of hairy vetch accessions and be certain that their starting breeding populations span the entire breadth of genetic diversity found in the USDA NPGS. Taking advantage of this information has the potential to reduce the overall cost in time and resources of any future breeding program for hairy vetch.
Understanding linkage between genotype and agronomically important phenotypes (early flowering, hard seed and winter hardiness) will facilitate cultivar selection and inform breeding programs concerned with the cover crop hairy vetch (Vicia villosa). . We used molecular and biochemical techniques to identify and evaluate a core germplasm collection of hairy vetch. Accessions of hairy vetch that originated throughout the world were acquired from the USDA plant germplasm collection. Plants were grown in Beltsville, MD and material was collected for analysis of genetic relatedness using genomic markers bases on Amplified Fragment Length Polymorphisms (AFLP). Phenotypic similarity was assessed using a visual rating assessment of percent flowering. Biochemical traits, % carbon and nitrogen, were measured using a Costech CN. We related parameters of genetic, phenotypic and biochemical diversity to the geospatial relatedness of the accessions. Based on genome marker analysis, the accessions cannot be grouped based on origin country of collection. But, there is clear evidence of derivative accessions that are likely products of recent hairy vetch breeding efforts in the United States. Biochemically, the accessions varied in their carbon and nitrogen content, nitrogen being the most variable with a range of 2.6 to 4.8%. These results provide base line information to identify a core genetic subset of the V.villosa germplasm collection. Information presented here may assist breeding efforts and eventually allow farmers to take advantage of this useful cover crop.This “core germplasm” consists of PI’s 167259, 206493, 229970, Nebraska common, 317447, 429408, 314404, 222217, 289482, Albert Lea, Groff selection, 575701, Purple Bounty, Purple Prosperity and 577753.