The development of a new high-yield, protein-rich corn, that could help prevent malnutrition in millions of people, has earned a Mexican biochemist and an Indian plant geneticist the Millennium World Food Prize.The World Bank has sponsored the US$250,000 award, which was given to Dr. Surinder K. Vasal, 62, and Dr. Evangelina Villegas, 76, last month. Both scientists belong to the International Maize and Wheat Improvement Centre in Mexico.Their invention, called quality protein maize, was developed over the past 35 years, through plant breeding and biochemistry. It looks and tastes like normal maize, but contains twice the amount of lysine and tryptophan: essential amino acids.The corn was based on the discovery in the early 1960's of a corn gene - opaque-2 - that had increased lysine and tryptophan content, but which led to low yields, increased susceptibility to pests and diseases, and more importantly, a pleasantly soft chalky grain.Vasal and Villegas developed the discovery in the field and in the laboratory, generating nutritional profiles of the plants.By the mid-1990s, QPM was tested with positive results and today, a crop is expected to be grown from around one million hectares in 11 countries across Africa, Asia, and Latin America.