The genes to provide the vitamin A were transferred to the rice from daffodils and bacteria. At the Agriculture Department, Anna McClung recently used the technique to develop rice that would be soft on the outside and firm on the inside after processing. The work was done with a company hoping to sell the rice in Europe, where opposition to genetically modified crops is high. So genetic engineering was out of the question. Both Pioneer and scientists at Purdue University used the technique to develop soybeans that are resistant to the cyst nematode.
Classical breeding can be a long and tedious affair.
Breeders might take a plant with a desirable characteristic, like disease resistance, and cross it with another plant with other desirable traits, like high yield. They then examine the offspring, hoping to find plants that have both disease resistance and high yield. Those desirable plants might be then crossed to make a new generation. The whole process can require 10 or more generations, thousands of crosses and 5 to 15 years. To see which offspring have the desired traits, the new generation usually must be allowed to grow up, and even then detection is often not easy.