2016. Western white pine (WWP, Pinus monticola) with necrotic needle spots. These needle spots are one indicator of major gene resistance (MGR) to blister rust. Sow year 2015. Dorena Genetic Resource Center, Cottage Grove, Oregon.

Western white pine (WWP, Pinus monticola) with necrotic needle spots. These needle spots are one indicator of major gene resistance (MGR) to blister rust. Sow year 2015. Dorena Genetic Resource Center, Cottage Grove, Oregon.

 

More from Richard Sniezko:

Most WWP progeny are very susceptible, but some parent trees have major gene resistance (MGR) and their progeny segregate for resistant:susceptible with ‘wild’ type races of the rust. The necrotic needle spots are one indicator of these resistant seedlings. However, this type of resistance can be overcome by virulent vcr2 races of the rust.

Contact richard.sniezko@usda.gov for more information.

 

Photo by: Richard Sniezko

Date: April 4, 2016

 

Credit: USDA Forest Service, Region 6, Umpqua National Forest, Dorena Genetic Resource Center.

Source: Richard Sniezko collection; Cottage Grove, Oregon.

 

For more about the Dorena Genetic Resource Center see: www.fs.usda.gov/detail/r6/landmanagement/resourcemanageme...

 

Image provided by USDA Forest Service, Region 6, State and Private Forestry, Forest Health Protection: www.fs.usda.gov/main/r6/forest-grasslandhealth

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