I grow some pretty rare plants that I would like to deposit into seed banks. Lets just assume the species' pollen is wind dispersed and the seeds can handle cold/dry storage. I am wondering what can be done to prevent contamination/hybridization when *pure* seeds are required. I have drawn up some plans for a small 8 cube wall design with is air filtered and all that, but it will require air conditioning (I live in a hot country in Asia) and expensive electrical costs. i would prefer to avoid that if possible. Am aiming for very good results, not mediocre results that would "be ok for most". the idea is to be as certain as possible what was in there breeding is what fertilized the seeds. Thanks for any ideas/suggestions/books/websites etc :) Should have added these are not big trees, but potted plants that are mobile. Larger trees I suspect would be very difficult. But next year when we have more fruit maturing, especially durian, we want to do this with trees as well for selective breeding. I am wondering if there is some kind of sheet material that has pores small enough to stop pollen and big enough to breath, I was thinking wrapping branches to seal before the flowers open, but I can see this causing severe problems with rot in wet/tropical type areas. but I think the general procedure would be the same for Canadian plants as well, with minor difference to make up for variable heat/moisture levels.