GA-TACF Science Progress 2022

The Georgia Chapter of the American Chestnut Foundation

2 months ago

The American Chestnut Foundation is seeking scion wood from wild American chestnut trees from the southern population. Population studies have determined that trees found in western TN and KY, GA, AL, and MS represent the southern population and are the most genetically diverse. The objectives of this collection are to:

🌱Conserve genetic diversity of unique and underrepresented populations of American chestnut through grafting

🌱Grow these grafted plants in favorable conditions (including growth chambers) to promote flowering and ease of pollen collection

🌱Future utilization of pollen and flowers to outcross transgenic chestnut

Goals for 2023: Gather around 100 sources from the South

•Coordinate with Jamie Van Clief at jamie.vanclief@acf.org for the collection of this scion wood.

•Scion wood collection should be done during winter dormancy only, which is commonly marked by the loss of leaves or brown leaves dangling (flagged) on their branches. Ideally, collected between December 2022–January 2023.

•It may be necessary to visit sites twice: once, before winter dormancy to ensure species can be identified to the American chestnut, particularly in areas where they co-occur with chinquapin. Second, when trees have gone dormant to collect scion wood.

•Scion wood should be at least 3 inches long and contain 1 or more unopened buds. With nut grafting, the diameter of the scion is not a concern, but larger buds with space in between buds are preferred.

•Collect ten pieces of scion wood per tree, when possible. At a minimum, we are looking for about fifteen buds. However, use judgment when collecting from small trees to not jeopardize the tree's survival by over-collecting.

•Take GPS coordinates from each tree using the TreeSnap application for smartphones (treesnap.org/) or with a GPS unit or smartphone. Ideally, trees have already been identified and entered into TACF’s dentataBase.

•Place scion wood from a single tree in a one-gallon sealable bag.

•For each tree, place a note card in the bag containing: data collected, county, state, latitude and longitude.
Previously used for breeding or not: Yes, No or Unknown
TreeSnap ID or wild tree code from Regional Science Coordinator (if applicable)
Public or private land (Do Not Trespass!)

•Before sealing, place the card in the bag, then roll the bag from the bottom to the top to remove excess air.

•Do not write on the bag as even permanent markers will fade or be scratched off during handling and storage. Temporary writing on bags is fine, but do not rely on them for storage.

• Do not place a damp paper towel in the bag. Moisture from the towel commonly causes mold during storage.

•If desired place them in damp (NOT WET!) peat moss in the bag. The peat moss should be damp enough that you can squeeze it into a ball but not so damp you can squeeze water out of it.

•While in the field, store scion wood in a cooler with cold packs and place it in the refrigerator's crisper drawer until shipping. Do not place it in the freezer.

•Please ship scion wood no later than 2-3 weeks after collection.

Shipping:

Ship on Sunday through Wednesday via 2-day shipping to the attention of Chance Parker. Do not ship on Thursday or Friday. Coordinate with Chance and Jamie Van Clief so everyone knows what has been shipped. Ship samples on cold packs and in small foam cooler, if possible.

Supplies:

Sealable gallon freezer bags
GPS unit or smartphone with TreeSnap (treesnap.org/)
Permanent marker for making notes on cards
Notecards or paper
Pruning shears and/or pole, depending on tree size
Cooler and cold packs

About Scion Wood

While trees are grafted just as the rootstock buds start to grow, the buds on the scion wood must be dormant at the time of grafting. Thus, February is an ideal time to collect scion wood for spring grafting.

After cutting scion wood, it can be sealed in polyethylene bags to prevent moisture loss and stored for three months at 32°F until grafting. Storage at lower temperatures in home freezers can damage the buds. Temperatures warmer than 32°F will shorten the storage life of the scion wood. Using scion buds that have begun to grow while in cold storage will result in grafting failure. ... See MoreSee Less