Thank you for taking time to try out our gamejam game. The [Harvest] button harvests fruit if the plant has fruit (which will give seeds), otherwise, it harvests the plant for Biofuel which allows you to turn on the generator.
From there, you can start crossbreeding plants. We hope to get this into a clearer and more robust state down the line. Basically ended up as a proof of concept by the end of the game jam.