Astronauts gone wild. "I don't know about the onions, but the weed grows great up here! We grew enough up here to last for the next few missions!" It's intere

Astronauts gone wild. "I don't know about the onions, but the weed grows great up here! We grew enough up here to last for the next few missions!" It's interesting to think how long these veggies could last within human civilization beyond Earth. How would our veggies evolve (only from genetic modification?) Would they be largely immune from disease in this environment? What would be the possibility of them hitting some sort of genetic dead end and us losing our entire supply? Could we create new types of veggies?