Treesearch

Threats to North American forest trees from exotic pests and pathogens or habitat loss, make it imperative that every available tool be employed for conservation and restoration of these at risk species. One such tool, in vitro propagation, could greatly enhance conservation of forest tree genetic material and selection and breeding of resistant or tolerant genotypes for restoration. In vitro propagation approaches include standard micropropagation (axillary shoot multiplication), organogenesis (adventitious shoot production) and somatic embryogenesis (SE), a process by which structures...

Association studies integrating environmental, phenotypic, and genetic data are key in understanding forest tree resilience to climate change and disease. As genomic resources increase, both in terms of complete reference sequences and magnitude of individuals genotyped, researchers are better equipped to identify correlations between genetic variation and adaptive or commercial traits. Computational resources designed to integrate and distribute high quality genotypic, phenotypic, and environmental datasets remain insufficient for the task. TreeGenes is a web-based resource dedicated to...

Genetic resource management programs across the U.S. Department of Agriculture Forest Service (USDA FS) play a key role in supporting successful land management activities. The programs are responsible for developing and providing plant material for revegetation, seed management guidelines, emergency fire recovery assistance, genetic conservation strategies, climate change guidance, and partnership opportunities. The primary objective of the USDA FS genetics programs is to provide the genetically most appropriate plant material to support diverse, sustainable and resilient forests. These...

Pinus strobiformis (southwestern white pine) is threatened by both a rapidly changing climate and the tree disease white pine blister rust, caused by an introduced fungal pathogen, Cronartium ribicola. We began a proactive program in ~2009 to sustain P. strobiformis that includes genetic conservation, research, and management strategies. Research is related to the silvics, ecology, genetics, and future climate profile of the species. The results of these investigations will be used to develop refined seed transfer zones and silvicultural approaches to managing southwestern white pine in a...

The U.S. Department of Agriculture Forest Service (USDA FS) National Seed Laboratory (NSL) began long term seed storage for genetic conservation, in 2005, for USDA FS units and cooperators. This program requires secure storage of both seeds and the data documenting the identification of the seeds. The Agricultural Research Service (ARS) has provided both of these services to the USDA FS through the NSL. Security backup, of all samples, is provided at the ARS National Laboratory for Genetic Resource Preservation. Forest Service seed sample data is stored in the Germplasm Resource Information...

European beech (Fagus sylvatica) is one of the most abundant tree species in Europe. Its genetic structure and diversity have been investigated using both molecular markers and adaptive traits as assessed in field and laboratory experimental tests looking at adaptative traits. A great deal of information also exists on the Quaternary history of the species and on plant communities associated with this keystone species. In France, the conservation of its genetic resources relies on both in situ and ex situ approaches. Some outlying populations at the margin of its distribution, that are...

Hybridization can result in the transfer of adaptations among species and may contribute to speciation processes. On the other hand, hybridization can also result in a loss of species diversity due to asymmetric gene flow between species (genetic swamping) and in low hybrid fitness. An understanding of the outcomes of interspecific hybridization is crucial for the management and conservation of tree populations. As a result of warming climates, it is expected that distribution ranges of species will shift, resulting in new zones between species and potentially new or increased hybridization...

Pinus aristata, Rocky Mountain bristlecone pine, has a narrow geographic and elevational distribution and is threatened by rapid climate change, the introduced pathogen Cronartium ribicola that causes white pine blister rust (WPBR), and bark beetles. The core distribution of P. aristata is near and at treeline in central and southern Colorado and extends into northern New Mexico with a disjunct population in northern Arizona. The combination of low genetic diversity, moderate population isolation, and a protracted regeneration dynamic puts populations at risk for extirpation by novel...

Yellowwood (Cladrastis kentukea) is an uncommon, relict, tree species with a disjunct distribution primarily in the Central Hardwoods region. Most common on rocky, sheltered slopes of the Cumberland Plateau in Tennessee and Kentucky, isolated populations occur on appropriate sites throughout the southern and central United States. In Illinois, Louisiana, and South Carolina, yellowwood is listed as endangered by state conservation agencies, but it is not federally protected. Yellowwood has increased in popularity as a street tree and is planted in or predicted to be suitable for urban...

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...