mmkay, i am coming from this from the other side-- I am a north american who moved out into the world and am usually looking for resources to plant the plants "from home" in my own zone here in south america, but I have been there and done that!! I also research for a living so I hope my ideas will be helpful for you.
Once you have the zones sorted, you can identify cities in these zones. My suggestion to you, from my
experience hanging with the plant folks here, is twofold:
1- look at social media, search for those cities and "plants" (or agriculture, or garden, depending on what success you're getting) in Russian. Also, search for those cities and 'slow food', since in areas where interest in heritage crops and stuff is just starting, the food and the plant people tend to overlap and they may be able to point you in the right direction. Join the groups and just ask your question in English, people tend to want to help.
2- for China, since searchable social media (esp
facebook) is blocked there, my advice for you is something you could also do with Russia-- look for universities in those cities and get the contact for the botany/plant science/agronomy department (if they are small cities, agronomy might be the best you'll be able to do).
Extra bonus- look for botanical gardens, even far, write them, and ask them who you could contact in those areas. For example-
https://www.bgci.org/garden.php?id=335
It will take a while, but plant people tend to really like talking to other plant people.
And maybe someone seeing this will "know a guy".
