The character is living in a world where grass is extinct. He works on a particular species of grass, researching and trying to reproduce it in the lab (but it is difficult because the cultures he is using are very very old).

In vitro regeneration of Lolium perenne

Your original thesis title would be fine if there were other people working on other types of grass and other people using different methodologies/source materials but working on the same grass.

If you mean more than a title, by the term "statement", then in a thesis, an abstract or proposal would be more appropriate, which is more the size of a paragraph.

However, it is your world, so you don't have to be kept to current expectations.

The effects of Streptozotocin-induced diabetes on latency to seizure in rats.

Its very easy to get an idea of what a thesis title should look like though. Just go here:

http://www.ncbi.nlm.nih.gov/pubmed