Genetic Resources, International Organizations, and Improvement in Rice Varieties*

Abstract

Improvement in varieties has helped spur enormous gains in rice productivity over the past several decades. Improved cultivars have been developed using genetic resources from the two cultivated species of rice (Oryza sativa and Oryza glaberrima) and from a few of the approximately 20 wild species of rice. These cultivars were obtained by shuffling and mixing the available pool of rice genes, known as germplasm. In this article we investigate to what extent specific international organizations and programs have spurred improvements in rice varieties. In addition, we assign value to an international collection of rice germplasm based on its contribution to improvement and productivity growth of rice varieties. For many centuries, improvement of rice varieties occurred slowly as the result of natural selection and seed-saving practices by farmers. Since the second half of the nineteenth century, however, new varieties have been created by scientists working at agricultural experiment stations, and over the past 45 years the pace of improvement in rice varieties has dramatically increased. Since 1960, the International Rice Research Institute (IRRI), located in the Philippines, has played a key role in worldwide efforts to develop improved varieties of rice. The institute has a number of programs to facilitate rice genetic improvement. The institute’s own plant-breeding program (IRPB) produces improved cultivars, both in the form of ‘‘varieties’’ that are ready for use in farmers’ fields and in the form of ‘‘advanced lines’’ suited for use as parent material in national plant-breeding programs. The International Rice Research Institute maintains an international collection of rice genetic resources (IRGC) designed to preserve