Forest Genetics Team

Management and conservation of genetic resources

New knowledge is needed to develop and evaluate options for the management of populations that maintain or enhance genetic diversity in the long-term while providing the basis for genetic improvement in health or productivity in the short-term.

Projects:

Gene Conservation
Breeding and deployment strategies
Inheritance of traits of interest

2.1 Gene conservation

The population sizes needed to maintain sufficient genetic variation to maintain a species indefinitely numbers in the thousands (Millar and Libby 1991, Lynch 1995, Lande 1995, Yanchuk 2001), which is typically more trees than can be found in any breeding population. Fortunately there is usually a large number of trees that can be found in in situ and ex situ reserves. However, the only way to ensure that sufficient numbers are present is to monitor our current forest reserves. The Team has been taking part in a “gap” analysis that documents the status of eight coniferous species in present reserves (Table 1). For six species there appears to be a sufficient number of reserves. For two species, there are specific seed zones that may require further conservation efforts. Future research will deal with: (1) a closer examination of the two seed zones that may need further conservation measures and development of appropriate gene conservation strategies, (2) developing ongoing protocols for continued monitoring of the genetic resources, and (3) expanding the conservation efforts to other species.

Team Principal Investigators: Brad St.Clair, Randy Johnson and Richard Cronn

Collaborators: Sara Lipow and Glenn Howe (Oregon State University), members of the Pacific Northwest Forest Tree Gene Conservation Group

Benefits: The benefits of this type of research lie in the insurance value for the future. We do not know what new pests or environments will be encountered, or what new traits may be desired, but we can expect that the conserved genetic variation will be needed to allow our native species to adapt to ever changing environmental and social pressures.

2.2 Breeding and deployment strategies

Tree breeding is an important tool in forest management. Tree breeding activities are underway for eight species in Oregon and Washington (Johnson 2000). The primary breeding objectives of these programs center around improving growth rate or disease resistance. The Forest Genetics Team’s research activities focus on various aspects the breeding and production cycle (Table 1). Breeding and testing strategies are researched in an effort to optimize the breeding effort. Past studies have examined optimum crossing designs, test numbers and generation intervals for traditional tree improvement programs. More recently, we have changed our emphasis from modifying growth traits to increasing disease and pest resistance. The Team is working with a graduate student at OSU to develop early screening protocols for Swiss needle cast on Douglas-fir and is also supporting the effort of the Northwest Tree Improvement Cooperative in breeding Sitka spruce for weevil resistance. Computer simulation studies continue to examine the efficiency of crossing designs and seed orchard selection strategies that can provide increased gain and genetic diversity over levels being achieved at present.

Future work is expected to examine factors that affect genetic diversity in native plant restoration efforts. These factors include the number of plants used in the founder population, the distance between seed source and planting site, and processes that may reduce genetic diversity in the seed-increase process.

Team Principal Investigators: Randy Johnson, Brad St.Clair and Richard Cronn.

Collaborators: Keith Jayawickrama (NWTIC director), Glenn Howe (PNWTIRC director), Sara Lipow (OSU), Fatih Temel (OSU graduate student)

Benefits: Increasing pest resistance and growth rate results in healthier forests in the short term (see Johnson and Lipow, in press). Maintaining genetic diversity will sustain Pacific Northwest forests in the long term. In some cases, actively breeding for pest resistance may be the only way to keep certain species viable.

2.3 Inheritance of traits of interest

Before one can manage a genetic resource, one must understand the genetic variation patterns in the populations of interest. For example, if genetic variation for a desired trait does not exist, it will be impossible to improve this characteristic through breeding. If there is genetic variation, but the genes for a specific trait are rare (like the MGR gene for blister rust resistance in white pine), then gene conservation strategies may need to be modified. Understanding the genetic interrelationships among traits is also important, because changing one trait may alter other traits. For example, breeding for increased growth rate in forest trees tends improve tolerance to disease but reduces wood density.

Studies that examine inheritance patterns are typically done in collaboration with clients that have an interest in breeding a species for a particular trait (Table 1). As a result, clients provide much of our data. Studies that examine Swiss needle cast tolerance in Douglas-fir use data provided by the Northwest Tree Improvement Cooperative, the Siuslaw National Forest, the Bureau of Land Management, the Oregon Department of Forestry and Plum Creek Timber Company. Trials used to examine weevil resistance in Sitka spruce were established by the British Colombia Ministry of Forest on private, federal and state lands in Oregon and Washington. We are examining characteristics that are important for bough production in noble fir with data from USDA Forest Service trials with the assistance of the Washington Department of Natural Resources. Growth and wood quality in west-side ponderosa pine is being examined in cooperation with the Willamette Valley Ponderosa Pine Conservation Association.

Team Principal Investigators: Brad St.Clair and Randy Johnson.

Collaborators: Northwest Tree Improvement Cooperative, Swiss Needle Cast Cooperative, Willamette Valley Ponderosa Pine Conservation Association, Jeff DeBell (WADNR), Dave Doede (Region 6 NFS)

Benefits: Results from these studies allow clients to understand the potential benefits from breeding and efficiently develop new breeding programs. In some cases, where certain traits can only be found in specific locals, results will direct gene conservation efforts.

US Forest Service - Pacific Northwest Research Station
Last Modified:  Wednesday, 12 January 2011 at 01:27:33 EST