I read quite a lot about this about 12 years ago and I see that there are still publications in astrobiology. NASA is probably your best bet.

Dear Graeme, thanks for your notes on your experiences. We are now having some projects including research on this Astrobiology especially with special reference On Agriculture. Our collaborators include JAXA, Japan. We are within the group of Seed Space for Asian Future. Thanks.

This may be of interest.

http://www.optimara.com/business/africanviolets/everfloris.html

http://www.popsci.com/article/science/cherry-trees-flew-space-bloom-six-years-early?src=SOC&dom=fb