William MacDonald, Essie Burnworth, Mark Double, Diane Shi, Robert Strasser, Michael Webb, Donald Nuss, Burnie Burnworth, Gary Carver, Gil Choi, Ron Kuipers, Jim Hill, Kathy Marmet. Photo taken by Barbara Knapp. Dr. MacDonald and his Research Assistant Mark Double traveled from WVU in Morgantown. Diane Shi and Dr. Gil Choi work with Dr. Nuss at the University of MD Biotechnology Institute. Michael Webb is a PATACF member who helped with the hypovirus innoculations at Sugarloaf in August 2007.

More Photos..

Mark Double's Blight Culture Photos

Thank you for coming to Sugarloaf last Friday. It was a treat for us to be able to walk around the chestnut trees with Don, and Diane and Gil from his lab, and Bill and Mark and hear what they had to say about the trees we treated with hypovirulent isolates from their labs last summer. We started in East Field, looked at many of the trees with yellow ribbons indicating that they had been treated. Then we went to West Field and looked mostly at the trees along the fence row to the right of the entrance, and then finally went to the Stone Bench on the Mountain where most people climbed down to see the 3-4 trees from which we had harvested nuts last year.

Although the overall results seemed inconclusive, some interesting things came up.

1. Many of the treated cankers seemed to have callus tissue, did not have orange stomata in evidence, and/or did not appear as reddish as in the photographs we took at the time of treatment. These observations point to successful treatments. Bill and Mark said that the bark appeared more rough and cankers were more extensive than they would expect on surviving trees. Some new cankers, and orange stomata near the treated cankers were also identified. In some cases, Bill and Mark said we should have made the treatments closer to the infected portion of the cankers; in other words, our treatment holes were not right on the margin but were more into the healthy tissue.

2. Bill and Mark speculated that the irradiation of the parents or grandparents had perhaps had some effects on the trees to allow them to survive more blight without dying. However, the same bark characteristics and canker appearances were evident on the Mountain trees that are wild and have no irradiation in their background.

3. Bill and Mark said that the Sugarloaf American chestnut trees do not look like other American chestnuts they have growing in West Virginia.

4. Bill confirmed what we had been told several years ago by Dennis Fulbright, namely that they had been unable to identify any wild hypovirulence in East or West Field trees in the 1990s.

5. Bill and Mark made several recommendations that may confirm the success of our treatments last summer and may also shed some light on the nature of the differences between the chestnuts in Maryland and elsewhere. Specifically,

• Sample 20% of the treated cankers -- 4 samples on each canker at 12, 3, 6, and 9 positions -- from these samples, Mark will be able to tell if hypovirulence is present and if so, whether it is Euro7 or 7-13 so we will know which virus-infected isolates are active.
• Sample some of the new cankers/untreated cankers -- from these samples, Mark may be able to tell whether the "soup" would be effective if we treated in future
• Sample cankers on Maryland mother trees away from Sugarloaf -- from these samples, Mark may be able to tell if wild hypovirulence is present to explain why the trees have not died.

6. New hypovirulent fungal strains will be given to us to make more soup. We will then treat newly identified cankers at Sugarloaf East and West Fields, cankers on the Mountain trees, and other Maryland survivors like Barbara Knapp's tree, Jim Hill's tree, the new champion near Barbara Knapp's property, etc.

Overall, this hypovirulence project appears to be a successful way to keep more of the Maryland survivors alive and flowering. It also may enable us to extend our learning to high school students and new volunteers who want to help.

We will continue to replant the Experimental Orchard designed by Dennis Fulbright to investigate the role of hypovirulence using Sugarloaf East Field, West Field and Mountain nuts. The Chapter has a lot of open pollinated American chestnut from Sugarloaf trees that are available for planting elsewhere if further experiments are warranted. 

Gary Carver and Ron Kuipers are collecting samples from survivors, and we will collect samples from the treated trees to send to mark who has graciously agreed to process the plugs and let us know what he finds. We will keep everyone informed as new information becomes available.

Best regards --

Essie and Burnie