Good quality seeds basically mean the most competent seeds, which will definitely give rise to a healthy plant, which would bear more healthy seeds. This is important when you're dealing with plants at a large scale, and you need to maintain crops for a large​ time frame.

Best wheat seeds would be ones who's color, shape and size are normal (not brownish, oddly shaped, tiny or bloated). Apart from just the looks, seeds are also tested for their efficiency in germination (how many seeds from set of 100 would grow in plants when sowed).