Tropical crops such as cowpea, yam, plantain, and cassava are heavily underresearched but, in addition to rice, maize, wheat, and potato, are important as primary or secondary food staples in the developing countries. The modern tools of molecular and cellular technology offer the opportunity not only to make substantial gains in knowledge of these crops, but also they overcome some of the obstacles which presently restrain both the genetic improvement and the productivity of these crops in tropical farming systems. Increased nutritional value of these crops, reduced post-harvest...