A significant part of the current efforts and resources invested in induced mutagenesis in plants (including the systematic molecular and morphological characterizations of mutant collections) is devoted to functional genomics. For a majority of the model plants and other intensively researched plant species, including major crop plants, huge amounts of genotypic and phenotypic data are being generated and housed in publicly accessible searchable databases. Typically, researchers rely on such information to request the characterized mutants for scientific investigations. Examples of plant mutant stocks that are publicly available to requestors include the model plant, Arabidopsis, maize, rice, barley, peas, cucurbits and tomato (Table 4). The U.S. Department of Agriculture, Agricultural Research Service (USDA/ARS) has a number of germplasm collections that hold publicly available characterized mutant stocks under the National Plant Germplasm System (GRIN) [50]. A number of public germplasm collections in other countries also have substantial number of mutant accessions that constitute a critical resource for the continually increasing plant functional genomics research community. Some of these mutant stocks are listed in Table 4.