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ARS Home » Southeast Area » Griffin, Georgia » Plant Genetic Resources Conservation Unit » Research » Publications at this Location » Publication #430785
Research Project: An Integrated Approach for Plant Genetic Resources Conservation, Characterization, Evaluation, Documentation, and Distribution

Location: Plant Genetic Resources Conservation Unit

Title: Selection of a core collection from the US castor bean germplasm collection

Author
item Morris, John
item Tonnis, Brandon
item CHEN, ZHENBENG - University Of Georgia
item Wang, Ming

Submitted to: Genetic Resources
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: 4/20/2026
Publication Date: 6/10/2026
Citation: Morris, J.B., Tonnis, B.D., Chen, Z., Wang, M.L. 2026. Selection of a core collection from the U.S. castor bean germplasm collection. Crop Science. 7(13):181-191. https://doi.org/10.46265/genresj.ZUEQ4037.
DOI: https://doi.org/10.46265/genresj.ZUEQ4037

Interpretive Summary: Castor bean is a plant that has medicinal, biodiesel, and automobile lubrication uses. There are 1,033 samples included in the USDA, ARS, National Plant Germplasm collection. In order to effectively study castor bean's oil content, fatty acid content, and plant characteristic variation, a reduced number of samples are needed. Therefore this study focused on the development of a reduced number of castor bean samples. Based on the chemical content and plant characters, we identified 126 castor bean samples useful for researchers.

Technical Abstract: Castor bean (Ricinus communis L.) is a medicinal, industrial and biodiesel crop that is adapted to marginal soils in hot, dry and semi-arid environments, but its genetic potential is not fully exploited. Genetic variation exists in different castor bean genebanks, which hold many germplasm accessions. Since there are large numbers of accessions (normally over 1,000 accessions) in any genebank, the efficient way to exploit genetic diversity is to establish a core collection (i.e. 10% of the collection, but maximally representing the genetic diversity of the entire collection). There are 1,033 accessions in the United States Department of Agriculture (USDA) castor genebank, but a castor bean core collection was not available. For assessment of the genetic variation, we evaluated up to 347 accessions with available morphological and seed production data in the Germplasm Resources Information Network (GRIN) for seven qualitative and quantitative descriptors (plant height, maturity, raceme length, seed colour, seed size, stem colour and seed numbers) and then analyzed seeds chemically using nine quantitative traits (oil percentage, palmitic acid, stearic acid, oleic acid, linoleic acid, linolenic acid, gadoleic acid, ricinoleic acid and dihydrosterculic acid content). Principal component analysis (PCA) was performed and showed that plant architecture, maturity, seed yield, oil percentage, and fatty acid profiles displayed the greatest genetic variation. Based on results from the above analysis, a core collection with 126 accessions was established. The selected accessions were classified into four groups. The results from morphological and chemical analysis were consistent. This core collection represents the genetic diversity of the entire USDA castor bean germplasm collection and can be used for genetic research and breeding improvement programmes.