corn is rather versatile. aside from being useful for food, you can make oil from it, you can make sugar from it, alcohol for consumption/fuel. very useful plant. wheat is good for consumption. rice is good but the farming of it requires a lot of water and labor, i wouldnt take it to mars. wheat is good in terms of dietary requirements and has many culinary uses. really i think corn is what id take, just on the grounds of how versatile it is. i very much doubt they would send you with only one crop though. part of it would be an experiment to determine which crops would survive best in the martian soil, so a large number of different species of seeds would be taken.
Ah who cares, we're only sending the people off to Mars to die anyways. I say keep all of the food for us still loyal to earth and let those martians figure it out for themselves.
Clearly wheat. And the best booze is made from sugar cane anyway.
Wheat. There is no competing with fresh-baked bread. And none of that corn bread business.
Odd,Spoiler:Barley's getting a lot of lovin'...