Lunar soil is inhospitable to plants because many of the nutrients it contains are locked up in tough minerals that the plants cannot break down. "It will not be able to support the growth of tomatoes" or other food plants, says Igor Brown of NASA's Johnson Space Center (JSC) in Houston, Texas, US.
Now, for me, tomatoes aren't that great as a main staple. They are nice in a sauce, but only with a grain product like pasta (which also requires eggs) or bread. Also, I would imagine a plant like a tomato has too much "waste" product: stems and leaves. People also forget how poisonous tomato stems and leaves are; they are a relative of the nightshade family of plants, which include eggplants, potatoes, peanuts, and the deadly poinsettia.
I would want a plant that is mostly edible, like carrots, onions, radishes, lettuce, celery, beets, and so on. Make the most of what we are growing per square inch.
Then I think of all the other stuff we need like salt, protein, sugars, and complex carbohydrates that rabbit food simply won't give us. I am sure we can create salt if we have the right minerals, and maybe we could use soy protein, but how long would a space farer last in such an isolated environment?