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United States Department of Agriculture

Agricultural Research Service

Research Project: Management of Temperate-Adapted Fruit, Nut, and Specialty Crop Genetic Resources and Associated Information

Location: National Clonal Germplasm Repository (Corvallis, Oregon)

Title: Vaccinium species ploidy assessment

Authors
item Hummer, Kim
item Bassil, Nahla
item Rodrigez, H. -
item Olmstead, James -

Submitted to: Acta Horticulturae
Publication Type: Abstract Only
Publication Acceptance Date: January 1, 2014
Publication Date: N/A

Interpretive Summary: The U.S. Department of Agriculture, Agricultural Research Service, National Clonal Germplasm Repository (NCGR), Corvallis, Oregon, maintains the national collection for Vaccinium L. germplasm. The NCGR genebank includes more than 1700 accessions, with representatives of 81 blueberry species from around the world. The primary collection of clonal blueberries and their wild relatives are maintained as plants in containers in greenhouses and screenhouses. The primary genepool for highbush blueberry, the primary crop of economic importance, is narrow. Breeders wish to expand their potential crossing parents to include representatives of the rich diversity present in the wild. Knowledge of the number of chromosomes is required for this task, but this information has not been available. The objective of this research was to evaluate the amount of chromosomes for species within the NCGR collection. The number of chromosomes was evaluated through analysis of leaves with a technique called flow cytometry. Many species native to the South Pacific and Southeast Asia were had two sets of chromosomes. The true blueberries and European blueberries each included had 2, 4, or 6 sets of chromosomes. Cranberries and their relatives had either 2 or 6 sets. Some unusual species had 3 sets. Some species from Meso- and South America, had 4 sets. The chromosome amounts from these and other species will be reported.

Technical Abstract: The U.S. Department of Agriculture, Agricultural Research Service, National Clonal Germplasm Repository (NCGR), Corvallis, Oregon, maintains the national collection for Vaccinium L. germplasm. The NCGR genebank includes more than 1700 accessions, with representatives of 81 Vaccinium taxa from around the world. The primary collection of clonal blueberries and their wild relatives are maintained as plants in containers in greenhouses and screenhouses. While the primary genepool for highbush blueberry (V. corymbosum L.), the primary crop of economic importance, has been within Section Cyanococcus, breeders wish to expand gene accessibility to include representatives of the rich diversity present in other sections. Knowledge of ploidy level is paramount for this task, but has been limited. The objective of this research was to evaluate ploidy levels of species within the NCGR collection. The base haplotype is x = 12. Ploidy was evaluated through flow cytometry using leaf samples. Many species native to the South Pacific and Southeast Asia were diploid (2n = 2x = 24). Sections Cyanococcus and Myrtillus each included diploid, tetraploid, and hexaploid members. Section Oxycoccus had diploids and hexaploids. Vaccinium dependens (G. Don) Sleumer (sect. Brachyceratium) and V. poasanum (Donn. Sm.) (synonym = Symphysia poasanum (Donn. Sm.) Vander Kloet) were triploid. Pyxothamnus members from Meso- and South America, V. consanguineum Klotzsch and V. corymbodendron Dunal, were tetraploid. These two are candidates for direct crosses with V. corymbosum. Ploidy levels from other species representatives within these and other sections will be reported.

Last Modified: 11/22/2014
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