By Lori Wollerman Nelson, ���سԹ�

A team at Washington State University Tri-Cities is researching the impact that a type of fungus could have on vineyard growth and associated nutrient uptake, which could lead to less watering and less fertilizer required for a successful grape crop.

Tanya Cheeke, assistant professor of biology, was awarded a $25,000 grant by the Washington State Grape and Wine Research Program to support a series of greenhouse experiments, as well as a two-year $40,000 grant to support a field experiment from the BIOAg program of the WSU Center for Sustaining Agriculture and Natural Resources.

Cheeke is working with graduate student KC Cifizzari and undergraduate Dylan Hartwig on the project specifically to understand the role that arbuscular mycorrhizal fungi, or AM fungi, play in plant nutrition and production for grapevines.

���سԹ� 85 percent of all plant species, including most crop plants, have an intimate relationship with AM fungi, Cheeke said. The naturally-occurring soil fungus forms a dense network of connections with the plant by inserting tiny threads, called hyphae, into its roots. Through this shared connection, the plant sends food to the fungus and the fungus increases water and nutrients available to the plant. AM fungi usually enhances plant nutrient uptake from the soil.

Cifizzari said they are including phosphorus treatments to see if the grapevines grown with AM fungi do just as well as plants that are only given fertilizer. If grapes grow as well with additional AM fungi and a lack of additional phosphorus as the grapes given only phosphorus, then adding AM fungi could reduce how much fertilizer vineyard managers need to apply to their vines, they said.

“The nice thing about AM fungi is that they are living organisms and the treatment should be self-renewing,” Cheeke said. “With fertilizers, you have to reapply regularly to get the same effect. That can be expensive.”

Merlot grapes are a popular varietal in Washington and were shown to respond more strongly as part of a greenhouse experiment by Cheeke and her team as compared to another varietal studied – Chardonnay.

Cheeke said the variability between varieties of crops is not uncommon, however, the researchers also caution that greenhouse conditions don’t necessarily mimic field conditions. Future research will investigate this further. A second greenhouse experiment to evaluate the effectiveness of different commercially-available AM fungi products is ongoing this fall.

“We will compare the growth of grape vines grown with three commercially-available AM fungi products, soil from a natural sagebrush habitat, and soil from a 50-year old vineyard,” Cheeke said.

The results of this study could help Cheeke know which AM fungi products to recommend to vineyard managers, if results prove successful.

Both Cheeke and Cifizzari are interested in the role that AM fungi could play in sustainable agriculture. Agricultural crops usually have reduced colonization of AM fungi because practices like applying fungicides and tilling the soil can deplete naturally-occurring sources of these fungi. Without their fungal helper, agricultural crops can require more water and fertilizer to be productive and can be more susceptible to plant diseases.

“Grape growers are very interested in the potential benefit of AM fungi, but they need more information to feel comfortable using it.” Cheeke said.

“Adding AM fungi to vineyard soils could be a way to make agriculture better for the health of the land and the people who work it,” Cifizzari said.

By Maegan Murray, ���سԹ�

RICHLAND, Wash. – A team at Washington State University Tri-Cities is studying how to transplant fungi to restore native plant populations in the Midwest and Northwest.

Mycorrhizal fungi form a symbiotic relationship with many plant roots, which helps stabilize the soil, conserve water and provides a habitat for many birds and insects, said Tanya Cheeke, assistant professor of biology. Some native plant species are more

dependent on mycorrhizal fungi than invasive plant species are, so when that fungi is disturbed, native plants may not be able to compete as well with invasive species, disrupting the natural ecosystem of the environment and inhibiting many natural processes, she said.

“One way to improve native plant survival and growth in disturbed environments may be to inoculate seedlings with native soil microbes, which are then transplanted into a restoration site,” Cheeke said. “We’ve been doing prairie restoration in Kansas for the past two years. Now, we’re also doing something similar in the Palouse area in Washington.”

Cheeke is working with a team of undergraduate and graduate students to complete the research. A group of her undergraduate students recently presented their project during the ���سԹ� Undergraduate Research Symposium and Art Exhibition. Those students include Catalina Yepez, Jasmine Gonzales, Megan Brauner and Bryndalyn Corey.

The undergraduate team spent the past semester analyzing the spread of fungi from an inoculated soil environment in Kansas to see how far the fungi had spread

into a restoration area. One year after planting, soil samples were collected at 0.5 meter, 1 meter, 1.5 meters, and 2 meters from the site of the inoculation in each plot. The samples were then tested for the presence of fungal DNA to see if the mycorrhizal species that they had inoculated with had reached the various distances from the inoculation points.

“The results will be used to inform ecological restoration efforts aimed at improving the survival and growth of native plants in disturbed ecosystems,” undergraduate student Megan Brauner said.

Cheeke said they are also looking at how microbes change across gradients of disturbed environments compared to pristine environments.

“We want to determine the microbes that are present in pristine environments, but are missing from disturbed sites,” she said.

Eventually, Cheeke said they would like to develop soil restoration strategies that other people can implement in their own environments.