- Associated Press - Sunday, March 27, 2016

DORENA, Ore. (AP) - Lisa Winn has given up counting the number of boxes, buckets and small earth-filled cones at the Dorena Genetic Resource Center near Cottage Grove, which contain thousands of tree seedlings grown from pine and cedar seeds collected throughout the Pacific Northwest.

It’s not hard to see why Winn, the center manager, hesitates to provide a number. The vast array of tiny and not-so-tiny trees, contained in 13 greenhouses and on 150 acres of U.S. Bureau of Land Management land outside of Cottage Grove, is part of a venture that brings to the property thousands of new tree seeds every year. The center collects the seeds and nurtures them into seedlings in the hopes of identifying those most resistant to disease, in particular two specific pathogens that have wreaked havoc among certain pines and a type of cedar.

When the center periodically succeeds in cultivating disease-resistant seedlings, it gives them to U.S. Forest Service nurseries for eventual planting in the wild.

The center, opened in 1966, is about to celebrate half a century of operation.

Fighting tree disease is tricky, especially in a time of climate change.

“What we’re seeing is a gradually changing ecology,” Winn said. “We find a tree that’s resistant to a pathogen, and then the conditions change. No one tree is perfect.”

The center’s mission in forest genetics and disease resistance research gets little public attention. Its exterior is underwhelming: just one building peeping out on a road next to Dorena Lake, east of Cottage Grove.

The resource center operates on a yearly budget of about $1.1 million from the U.S. Department of Agriculture, not counting additional grants. It employs 19 permanent and five temporary employees.

The center works almost entirely on the pathogens Cronartium ribicola and Phytophthora lateralis, more commonly known as the cause of white pine blister rust and of Port-Orford-cedar root disease, respectively.

Preventing damage

White pine blister rust harms every type of white pine. Port-Orford-cedar root disease harms only Port-Orford cedars. White pine is found throughout Oregon at varying elevations; Port-Orford cedar is found mainly in southwest Oregon and northwest California.

The disease damage to the two types of tree cuts the diversity of forests and can cause soil erosion and flooding. It also can disrupt wildlife that use the trees. White pines are known to provide shelter and food for a number of birds, including the red crossbill, and mature trees can grow up to 200 or 250 years old, providing stability to the forest system. Port-Orford cedars can grow to several hundred years in age.

The research starts with government and private-sector employees who gather white pine and Port-Orford cedar seeds from trees throughout Washington and Oregon.

The seeds are sent to the Dorena grounds, where they are catalogued with specifics about where they were collected. Then they’re planted.

Later, as seedlings, they are infected with the pathogens. A multi-year process then tracks which, if any, of the seedlings have the genetics or other characteristics to mostly survive the infection.

Once the survivors are identified, more seed can be collected from the trees that produced the initial disease-resistant batch, and used to develop disease-resistant stock.

Throughout Northwest

The Port-Orford cedar’s root disease was first discovered in Seattle in 1923. Since then, it has spread throughout the Pacific Northwest. Port-Orford cedar is valued for its lumber, which has a fragrant ginger aroma, straight grain and rot resistance, which makes the wood ideal for carpentry.

The root disease “tends to kill off our younger trees. Our older trees tend to regenerate,” Winn said.

The root disease is spread by water. The center sends Port-Orford seedlings to Oregon State University for infection.

“They infect it in the lab with a rooting solution,” said Richard Sniezko, a geneticist who has been with the Dorena center since 1991.

The seedlings are then brought back to the center, put into a rooting area and monitored for three years. In the vast majority of seedlings, the infection takes hold and the seedlings yellow and die.

“Progeny 17490”

But sometimes seeds are found that prove resistant. Center workers take note of these survivors and alert the agency that provided the seed, so they can go back, collect more, and use it to generate more seedlings.

One of the tough seedlings is known as “the progeny 17490,” says Sniezko. This Port-Orford cedar had 100 percent resistance to the root disease. Now, it’s used regularly for crossbreeding, as are a number of other fairly disease-resistant Port-Orford varieties. Working as the Drs. Frankenstein of trees, the center employees crossbreed to create seedlings more able to bear up to exposure to infection. Grown at a containerized orchard on-site, the seedlings are provided to government and private-sector partners for planting.

“We want genetic diversity,” Winn said. “We’re looking for a rare, resistant number of trees to pollinate each other.”

The second program at Dorena, the white pine blister rust research, addresses a bigger problem, as white pines - and the blister rust - are spread throughout the United States.

White pine blister rust, present in a number of European countries as well as the United States, was first discovered in the United States in the first quarter of the 20th century, according to the American Phytopathological Society.

The disease is caused when spores from a currant or gooseberry plant infects pine needles. The resulting fungus grows on the inner bark of the tree, spreads as light yellow spots and often develops into orange cankers, causing the tree to die.

During the Great Depression, the Civilian Conservation Corps tried to combat the spread of the blister rust by trying to eradicate currant and gooseberry plants. But that proved impossible.

As is the case with the Port-Orford cedar root disease program, employees work to find which of the white pine seeds produce seedlings resistant to infection.

All types of white pines

The center gathers seeds from five native white pine species - western white pine, sugar pine, whitebark pine, limber pine and bristlecone pine.

“We’re looking at all types of white pines that exist,” Sniezko said. The center receives many thousands of seeds every year.

A number of seeds from the same families and species are planted in large boxes, infected in a large storage building with Ribes spores, then monitored for at least seven years.

A number of western white pines that now are 12 years old are showing resiliency against infection, continuing to grow despite the emergence on their trunks of bulbous diseased lumps. “These trees that have been able to wall off the disease are still surviving,” Winn said.

Expanding awareness

As it reaches its 50-year mark, the center increasingly is operating with greater access to technology. Documents and charts of each seedling, first kept in paper files, are now tabulated on a computer.

The center also is becoming more energy efficient. In the next few months, it will install solar panels, estimated to save 60 percent of electricity costs.

What hasn’t changed is lack of public awareness about that the center does, Sniezko says.

Now, Sniezko is applying for a grant from the New Phytologist Trust, an international not-for-profit organization studying plant science. Sniezko hopes to use grant money to hold an international conference on tree species and invasive pathogens, with a particular focus on how to speed up the testing that now takes many years.

In the meantime, the center is reconciled to slow progress in finding seeds that can fight back against disease.

“We’re lucky we have resistant native species,” Sniezko said.

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Information from: The Register-Guard, http://www.registerguard.com

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