Wheat is the most intensively bred species in the world. It is second to rice in world production, which in recent years has approached 550 million metric tonnes per year (Young et al. 1990). The bread wheats (Triticum aestivum L.) are divided into four main categories, based on the protein content of the grain. Hard red spring (11 to 18% protein) and winter (9 to 15% protein) wheats are used primarily for bread. Soft red winter (8 to 12%) protein) and white (8 to 11% protein) wheats are used primarily for muffins, noodles, cakes, crackers, and cookies. Durum wheat (Triticum durum L.) is used primarily for macaroni and pasta. While an extremely adaptive crop, wheat is still subject to many diseases, which makes genetic engineering an appealing biotechnology for wheat improvement.