Cereal germplasm resources.

The role of cereal germplasm banks is to collect, maintain, preserve, and distribute seeds representing the genetic diversity of crop species. While germplasm resources have traditionally been used in breeding efforts to improve a crop plant, they have also proved useful in both applied and basic research efforts to give insight into the biology of a crop plant (Harlan, 1975; Hyland, 1977; Sprague, 1980; Tanksley and McCouch, 1997; Damania, 2008; Johnson, 2008). Seed collection and exchange began in prehistoric times as agriculture developed and spread. Early historical examples were found from Egypt and Babylon (Hyland, 1977). Until recently, the ability of scientists and researchers to maintain and preserve plant genetic resources was very limited. Few countries had the capability to store crop seeds for long periods. There were insufficiencies, not only in facilities and staff but also in the technology needed to collect, store, and document germplasm holdings (Harlan, 1975; Sprague, 1980). Vavilov first called attention to the potential of crop relatives as a source of novel trait variation for crop improvement (Vavilov, 1926, 1940). It was this promise that motivated the establishment of modern germplasm banks, living seed collections focused primarily on exotic races and species that are closely related to crop cultivars in present use. Vavilov continued and expanded collection efforts that were initiated by the Russian Bureau of Applied Botany in 1894, which led to the establishment of the germplasm bank at what is now called the N.I. Vavilov Research Institute of Plant Industry (Sprague, 1980; Damania, 2008). The introduction of potentially useful plant species and crop varieties into the United States dates back to the early 19th century when embassies were asked to collect and send these materials to the United States. A more organized effort was initiated when the Section of Seed and Plant Introduction was formed in 1898 within the U.S. Department of Agriculture (USDA). However, no provisions were made to store these materials adequately and most of these initial collections were lost over the years (Wilson et al., 1985). Researchers working with maize (Zea mays) established a tradition of sharing resources and tools to further fundamental research efforts in this model biological organism (Freeling and Walbot, 1994; Neuffer et al., 1997) and formally organized the Maize Genetics Cooperation in 1932 (Kass et al., 2005). Among the aims of this organization were the collection and dissemination of unpublished data and information to interested workers and the maintenance and distribution of tester stocks. A collection of stocks was assembled and maintained and samples were supplied upon request; its first formal crop was grown in the summer of 1936 (Sachs, 2009). The Maize Genetics Cooperation Stock Center (Table III) became a model for the establishment of other model organism genetic stock centers. It also provided a model to those establishing general germplasm banks for crop species. Subsequently, the four original Regional Plant Introduction Stations were established under the Research and Marketing Act of 1946. This was the forerunner of the USDA National Plant Germplasm System (NPGS; Table I). The North Central Regional Plant Introduction Station at Ames, Iowa (Table III), which was the first station established, began operation in 1948 (Wilson et al., 1985; White et al., 1989). Also following World War II, the Food and Agriculture Organization of the United Nations became the main organization promoting the conservation of plant genetic resources. Its Consultative Group on International Agricultural Research (CGIAR; Table I) established the International Board for Plant Genetic Resources (IBPGR) in 1973 (Sprague, 1980). Since it began, IBPGR has worked to establish a global network of germplasm banks and has supported and stimulated the collection germplasm samples (Plucknett et al., 1987). IBPGR has also provided training, specialized equipment for storage and documentation, and advice. Today, more than 100 germplasm banks are operating in the world; many of these are located in developing countries (Tables I–III). By contrast, when IBPGRwas established in 1974, only about six countries had the capability to store seeds for long periods (Plucknett and Horne, 1992). 1 This work was supported by the U.S. Department of Agriculture-Agricultural Research Service (CRIS project no. 3611–21000– 022–00). * E-mail [email protected]. The author responsible for the distribution of materials integral to the findings presented in this article in accordance with the policy described in the Instructions for Authors (www.plantphysiol.org) is: Martin M. Sachs ([email protected]). www.plantphysiol.org/cgi/doi/10.1104/pp.108.129205