Considering that Thrawn and C'baoth have cloned a Jedi before (Luke) they can obviously artificially reproduce midichlorians. It is apparently possible to make midichlorians and then transfer them to regular humans or aliens and make Jedis.  This also raises the issue of blood transfusions, could they pass on Jedi traits from jedi blood, or do all jedi have a unique blood type?  Can we make Jedis out of regular humans and Aliens?  This is one issue that ought to be further researched.