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Post by Admin on Jan 27, 2023 14:57:08 GMT -3.5
I'm still playing around, and invented some categories? boards? just for practice. The Canadian Chestnut Council members will have a better idea of how this system might be broken down into sub-systems than do I. But when they decide, I want to be ready to serve them! Chee4rs, Chris
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Post by jocelyn on Jan 28, 2023 17:22:51 GMT -3.5
The CCC posted this on their facebook page about the blight resistance breeding
Our chair sent this in answer to your question: The research plot was started in 2011 and consists of only F2 (second generation) trees. Row 13 was planted in 2015 so they are eight years old . The work of breeding a blight resistant American Chestnut based on native resistance to the blight is progressing well. The CCC is establishing F3 (third generation) orchards using progeny of the most blight tolerant F2 trees that have been tested. The testing of the F2 trees with blight inoculate continues to identify native resistance. Such identified trees are incorporated into the breeding program to generate the F3 which should demonstrate greater blight tolerance. We anticipate the first F3s to begin nut production in 2026 which will be the be F4 (fourth generation). The CCC anticipates that the F4 will be highly tolerant to blight or possibly resistance. Many trees in the wild and the F1 & F2 in the research fields continue to survive the blight despite being under attack continuously from the blight load present which demonstrates the native blight resistance, The CCC is also working to preserve and enhance the wild population and its genome through Breaking Isolation and Gene Conservation Seed Colonies which is also increases the opportunities for native resistance to increase.
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Post by chrisgreaves on Jan 30, 2023 13:59:15 GMT -3.5
[/quote] The CCC posted this on their facebook page about the blight resistance breeding Our chair sent this in answer to your question: The research plot was started in 2011 and consists of only F2 (second generation) trees. Row 13 was planted in 2015 so they are eight years old. Thank you Jocelyn. If I have understood this correctly, CCC has set up a program of Selective Breeding where the most suitable offspring are carried forward into the next round of breeding. And since the American Chestnut needs three or four years to start fruiting, each breeding cycle will span three or four years. That is, one might predict F5, F6, F7 and so on to appear at successive 3 or 4 year intervals, say 2030, 2034, 2038 and so on? And this would be a separate avenue of research. So the CCC has two avenues:- (1) Careful selective breeding of a domestic stock and (2) Opportunistic isolation of "wild" trees that appear to be blight-resistant. And finally testing is performed by shooting blight into the trees to check that they can, indeed, resist the blight. Thanks, Chris Greaves
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Post by jocelyn on Jan 31, 2023 16:20:52 GMT -3.5
You are pretty close. They plant each generation on an ongoing basis, so there can be several planting years for each generation. Most trees make pollen at 7 or 8 years, and nuts at 10 to 15 years. As a wild species, they have not yet been selected for early bearing, and are quite variable that way. The blight is grown in the lab, then a small circle is punched in the bark and blight pushed in the hole. They tape over the hole and wait to see what happens. Wild trees and tame trees are kind of the same, as trees keep showing up in the woods or old church yards, and pollen is gathered from trees as they are found and used.
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Post by chrisgreaves on Feb 1, 2023 10:16:43 GMT -3.5
You are pretty close. They plant each generation on an ongoing basis, so there can be several planting years for each generation. Most trees make pollen at 7 or 8 years, and nuts at 10 to 15 years. As a wild species, they have not yet been selected for early bearing, and are quite variable that way. The blight is grown in the lab, then a small circle is punched in the bark and blight pushed in the hole. They tape over the hole and wait to see what happens. Wild trees and tame trees are kind of the same, as trees keep showing up in the woods or old church yards, and pollen is gathered from trees as they are found and used. So the planting in each year mimics, to some extent, a nut-fall each season? Last year I had a plot of pumpkins sprout from a previous years seeds, so I reasoned that the seeds sown (wildly) in 2021 did not all germinate, but a half-dozen of them rode through a winter, a summer, and a following winter and THEN germinated. (The plot is described at "We ripped the asphalt of the second driveway." partway down the Soil Remediation web page). I imagine that the seeds are well-catalogued and diaried so it will be possible to trace back in a database of transactions and determine ideal conditions for any future blight-resistant tree.
Who analyzes the database? Without analysis it is just data and provides no Information. Cheers, Chris
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Post by jocelyn on Feb 1, 2023 12:04:07 GMT -3.5
The U of Guelph analyses the data, as we have a tree breeder, a DNA guy and some graduate students. Many of the board members are retired geneticists too, so it's all good. Then, we have folks with a statistics background, all volunteers. It's actually pretty simple: you inocculate a tree, it dies or not. If it lives, then how does it do? Still alive after 5 or 6 years and healing up, breed it. Trees with one parent healed up from blight are F1. Planting a bunch of nuts from that cross (one parent healed up) gives a seed orchard that produces F2. All trees from the seeds from F1's will be F2's. Some got unlucky in the genetic shuffle and didn't get the blight resistance genes, those ones die when you give them the blight. The ones that are left will do better or worse than average, so you just wait. Still alive and healing up at year 5 or 6, breed them when they are old enough.
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