OREGON STATE UNIVERSITY

Gourmet Mushrooms Moving to the Greenhouse?

01/23/1997

CORVALLIS, Ore. - Researchers at Oregon State University and in Sweden today reported in the journal Nature the successful cultivation, for the first time ever, of the golden chanterelle mushroom in a greenhouse setting.

This won't mean the demise anytime soon of the budding Pacific Northwest industry that picks millions of dollars worth of this delicacy each year -often for consumption in the fine restaurants of Europe.

But the findings do point the way to understanding the reproduction and genetics of this prized mushroom, may have important ecological implications and could eventually lead to commercial applications.

"Part of what was so surprising was that we were able to cultivate this mushroom along with pine tree seedlings that were only 16 months old," said Francisco Camacho, a doctoral candidate with the OSU Department of Botany and Plant Pathology. "The convent ional wisdom was that it takes mature trees to support the fruiting of this species."

Camacho was a co-author on the Nature publication with Eric Danell, an OSU researcher during 1995 who is now a faculty member at the Swedish University of Agricultural Sciences.

A Swedish company, Cantharellus AB, will support further research on this phenomenon. Work is under way in Sweden aimed at commercial applications and a deeper understanding of the reproduction of chanterelles. Experiments with the Japanese delicacy matsu take is also progressing.

"This breakthrough will have great impact on research and cultivation of other edible mycorrhizal mushrooms," Danell said.

At a Swedish laboratory in 1988, Danell isolated the mycorrhizal fungus which later produced a fruiting body of the golden chanterelle mushroom, and mycorrhizal colonization had become routine by 1992. Swedish greenhouse experiments were continued in Oreg on during 1995 when Danell was a visiting scientist at OSU.

This fungus grows in "symbiosis" with the roots of trees, eventually producing the mushroom or fruitbody which in turn releases spores for the further dispersal of the fungus. It had been believed that this process of mushroom production only happened wit h older, mature trees in a forest setting.

"We were quite surprised when we found one of these mushrooms sprouting out of a little pot in the greenhouse," Camacho said. "It's now clear that older trees are not essential for reproduction."

Mushrooms such as this, the researchers said, may have ecological values far beyond their role as a gourmet delicacy. Scientists are still exploring how they could affect forest health, the productivity of ecosystems and food availability for various wild life species.

The ability to grow this mushroom in a controlled greenhouse setting, Camacho said, does not automatically translate to the same success in a more variable outdoor setting.

But being able to study the process in a lab, he said, should help the researchers learn far more about its biological and reproductive processes, and the same cultivation technique might prove to be applicable to other edible or endangered species.

Commercial production of chanterelles, the scientists say, may one day be possible. Another mushroom delicacy, truffles, are now grown in "orchards" through fungal inoculations.

In the Pacific Northwest, the golden chanterelle is found widely in conifer forests, most often Douglas-fir and hemlock. More than a million pounds are picked each year and wholesale prices for export of the delicacy have exceeded $20 a pound in some rece nt years.

The value of these and other mushroom crops is now sufficiently high that studies have been done to examine how various timber harvests or forest management techniques might affect mushroom production.

Regulations are also evolving on how to limit and regulate mushroom picking as various conflicts have emerged. OSU has helped lead research efforts to learn more about fungal ecology and create a scientific basis for their management as a special forest p roduct.