Over The Horizon

Mycorrhizal Magic

Scientists are helping to expand and diversify our mushroom industry so that New Zealand can become part of a billion-dollar export trade.

"About half of the world's edible mushrooms belong to the mycorrhizal group, and five of these have well established worldwide markets worth more than $4 billion," note research leader, Dr Ian Hall of Crop & Food Research.

Mycorrhizal mushrooms live in a beneficial relationship on the roots of suitable host trees. One mushroom, which has had particular success, is the Périgord black truffle.

"This year has produced a bumper harvest in a Gisborne truffire with 45kg of truffles located -- a yield similar to the best European truffires and one which we hope will be maintained for the next half century," says Hall.

Mushrooms are in demand from countries almost everywhere but particularly in Asia, North America and Europe.

"Many New Zealanders are surprised when they learn that the world market for mushrooms is measured in tens of billions of dollars, that there are more than 300 species of edible mushrooms and that only a third of all mushrooms consumed around the world are button mushrooms," says Hall.

"Over the past 30 years or so there has been a dramatic change in the range of foods to which the average Kiwi has had access. For this we can thank the new breed of chefs, entrepreneurs, gourmets and not least the new New Zealanders, particularly from the Pacific Islands, East Asia and Europe, who have tempted our palates with exotic and unusual taste experiences. Despite this, the average Kiwi is still rather wary of new foods."

Hall says this hesitancy is particularly marked where new mushrooms are concerned because of the belief that the only really safe ones to eat are button mushrooms.

"However, there is a golden opportunity to produce these high value foods in New Zealand for out-of-season Northern Hemisphere markets -- the goal of Crop & Food Research's edible mushroom programme."

The fact that these mushrooms grow on the roots of trees in a beneficial relationship is also helping another area of research into improving the health of some of our exotic forest trees such as Douglas Fir.

"All forest trees in New Zealand form a mutually beneficial relationship with mycorrhizal fungi. These dramatically increase the growth of the tree through stimulating the uptake of soil nutrients such as phosphorus, but can also benefit plant growth in other ways such as improving resistance to drought or root pathogens," says Hall.

Hall and fellow scientist Dr Wang Yun believe that the establishment of industries in New Zealand based on the cultivation of novel mycorrhizal edible mushrooms could provide rich rewards for New Zealand providing we can maintain our current lead on other Southern Hemisphere countries.