GA-TACF members and other chestnut enthusiasts,
We just wanted to give a quick update on some of the activities going on in our chestnut breeding and disease resistance program. Many of you have expressed interest in volunteering, and very soon we will have some activities to which we can invite groups. Most of our work so far this year is being effectively handled by our landowner/orchard stewards, and by our board members, science coordinators, and student interns.
One of the main tasks this summer has been the continued evaluation of trees for disease resistance (both to chestnut blight and to Phytophthora root rot), followed by culling of trees with the least resistance. These activities have taken place at the main Berry College orchard, two orchards at the Austin Flint property near Waleska, Scott Frazier’s Bottomlands Farm near Taylorsville, and the Henry orchard near Armuchee. Trees at the Austin Flint North Ridge site also received another round of inoculation with Phytophthora cinnamomi (trees at that site are being screened for resistance to that pathogen).
Another main task has been to prepare for and conduct hand (controlled) pollinations. The main types of pollinations that are being done are:
1) pure American chestnut crosses – to obtain seeds for germplasm conservation purposes and future breeding.
2) specific crosses among backcross trees – to determine if targeted crosses can improve disease resistance in comparison with open-pollination.
3) pollination of backcross trees with pollen bearing the OXO transgene – principally to begin the process of adding the OXO gene to trees with a Georgia American chestnut genetic background.
Hand pollination involves first covering immature burs with pollination bags, then coming back about two weeks later to add the chosen pollen to the flowers. The photos seen below show some of the steps involved.
A third type of activity is one for which we will be able to use some extra hands. This is the inoculation of orchard and nursery trees with the blight pathogen. The process involves infecting trees with the fungus in a controlled fashion. At various times afterward, the cankers that are induced are evaluated to assess the trees’ resistance. The main sites where volunteers might be needed include the Flint orchard near Waleska and the Berry College nursery near Rome. Please watch for announcements about these mid-July activities and let us know if you could help. We generally work in assembly line fashion, and each specific job is not very technical.
Finally, since early February we have been growing and maintaining a large number of backcross seedlings and a small set of seed-grown and grafted American chestnuts from Georgia. We have ~1000 trees in the Berry College nursery, many of which will need to go to orchard sites in the late fall or winter. We are coordinating with various owners of existing and planned orchard sites as we make plans for these trees.
Please also look forward to some upcoming public outreach events. Now that restrictions are easing up somewhat, we will begin to plan more fun activities (not that orchard and nursery work isn’t fun!).
Thanks again for all of your support and for your patience as we transition back to a more normal chapter activity schedule. If you are interested in volunteering, but can’t make it to either the Waleska or Berry College events, please let us know. We may be able to set you up to volunteer with an existing project near you – we have things going on all over the state!
Yours,
Kathy Patrick, GA-TACF President
P.S. Our new board members, Vincent Payne, David Keehn, and Caitlin Conn were all approved via a unanimous email vote!
 Dr. Caitlin Conn learns how to pollinate chestnuts at the Berry College germplasm conservation orchard. |
 Dried pollen is added to a clean glass slide by carefully inverting the bottle. Notice the coat of pollen on the center of the slide. |
 Once the slide is loaded with pollen, the bags are removed and the pollen is rubbed onto the styles of the receptive burs. |
 Berry College student intern Eden Young pollinating chestnuts at the college’s germplasm conservation orchard. |
