Food grain and Wheat berry

Food grain noun - Foodstuff prepared from the starchy grains of cereal grasses.

Wheat berry and food grain are semantically related. In some cases you can replace phrase "Wheat berry" with "Food grain", this phrases are similar.

Wheat berry noun - Grains of common wheat; sometimes cooked whole or cracked as cereal; usually ground into flour.

Food grain and wheat berry are semantically related. You can use "Food grain" instead a noun phrase "Wheat berry".