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Applied genetic conservation of Hawaiian Acacia koa: an eco-regional approach

Informally Refereed

Abstract

Koa (Acacia koa) is a valuable tree species economically, ecologically, and culturally in Hawaii. A vascular wilt disease of koa, caused by the fungal pathogen Fusarium oxysporum f. sp. koae (FOXY), causes high rates of mortality in field plantings and threatens native koa forests in Hawaii. Producing seeds with genetic resistance to FOXY is vital to successful koa reforestation and restoration. The Hawaii Agriculture Research Center (HARC), with both public and private partners, operates a tree improvement program to develop koa wilt resistant populations in Hawaii. The population genetics of koa are poorly understood across the broad range of habits that koa occupies and seed zones have not been sufficiently established. Thus, HARC estimates seed zones based on biogeographic variables and has selected wilt resistant koa populations for six ecological regions (eco-regions) in Hawaii. This conservative approach, based on planting locally sourced germplasm, is often a requirement of many restoration programs in the state. We further consider population genomic (single-nucleotide polymorphism) data in relation to the proposed eco-regions. Preliminary analyses suggest genetic differences among and within islands that are broadly consistent with eco-regions, but also suggest additional population differences that should be considered in genetic conservation of koa.

Parent Publication

Citation

Dudley, Nick; Jones, Tyler; James, Robert; Sniezko, Richard; Wright, Jessica; Liang, Christina; Gugger, Paul F.; Cannon, Phil. 2017. Applied genetic conservation of Hawaiian Acacia koa: an eco-regional approach. In: Sniezko, Richard A.; Man, Gary; Hipkins, Valerie; Woeste, Keith; Gwaze, David; Kliejunas, John T.; McTeague, Brianna A., tech. cords. 2017. Gene conservation of tree species—banking on the future. Proceedings of a workshop. Gen. Tech. Rep. PNW-GTR-963. Portland, OR: U.S. Department of Agriculture, Forest Service, Pacific Northwest Research Station: 78-91.
https://www.fs.usda.gov/research/treesearch/55089