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United States Department of Agriculture

Agricultural Research Service

Title: Use of Molecular Markers in the Management of Citrus Germplasm Resources

Authors
item Krueger, Robert
item Roose, Mikeal - UNIV OF CA, RIVERSIDE

Submitted to: Journal of the American Society for Horticultural Science
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: August 15, 2003
Publication Date: November 15, 2003
Citation: Krueger, R., Roose, M.L. 2003. Use of molecular markers in the management of citrus germplasm resources. Journal of the American Society for Horticultural Science. 128:827-837.

Interpretive Summary: New potential citrus germplasm accessions may be received as seed rather than budwood, thereby reducing phytosanitary risks. However, trueness-to-type may be an issue with seed materials because many varieties produce both apomictic (nucellar) and sexual (zygotic) embryos and most citrus is fairly heterozygous. The nucellar seedlings will be genetically identical to the mother plant and to each other. ISSR markers were utilized to identify genetically identical seedlings from received seed lots. These represent nucellar seedlings and thus the 'type'. This technique allowed the more rapid identification of nucellar seedlings compared to the traditional techniques and so improved the efficiency of introduction and maintenance. Identification of nucellar seedlings in this manner still necessitates the use of traditional characterization and evaluation processes. The method identifies those seed sources that produce few or no nucellar seedlings, but it is not useful for determining which seedlings of monoembryonic types should be retained in collections.

Technical Abstract: New potential citrus germplasm accessions may be received as seed rather than budwood, thereby reducing phytosanitary risks. However, trueness-to-type may be an issue with seed materials because many varieties produce both apomictic (nucellar) and sexual (zygotic) embryos and most citrus is fairly heterozygous. The nucellar seedlings will be genetically identical to the mother plant and to each other. ISSR markers were utilized to identify genetically identical seedlings from received seed lots. These represent nucellar seedlings and thus the 'type'. This technique allowed the more rapid identification of nucellar seedlings compared to the traditional techniques and so improved the efficiency of introduction and maintenance. Identification of nucellar seedlings in this manner still necessitates the use of traditional characterization and evaluation processes. The method identifies those seed sources that produce few or no nucellar seedlings, but it is not useful for determining which seedlings of monoembryonic types should be retained in collections.

Last Modified: 10/24/2014