• Notified varieties are developed and tested through multi-location trials by the All India Coordinated Crop Improvement Programme. If the varieties are found to be superior, the Central Seed Committee (CSC) releases them through notification in the official gazette
• Nucleus seeds are the pure genetic material of a notified variety produced by a breeder. These are multiplied into breeder seeds
• Breeder seeds have high purity (above 98 per cent usually) and are produced from the nucleus seed under the direct supervision of a plant breeder.Breeder seeds should be genetically pure enough to guarantee that the subsequent multiplication (into foundations seed) conforms to the prescribed standards of genetic purity
• Foundation seeds are given to the seed-growing farmer. Its production has to be under supervision or approval of a certification agency appointed by the government
• Certified seeds are sold/distributed to farmers for growing crops. They are supposed to guarantee specific genetic identity and standards prescribed for the crop by scientists. The progeny of a certified variety seed can be reused by farmers without much loss in productivity for a few generations
• Hybrid seeds are the first generation of a cross of two varieties. Private companies prefer these as they can't be saved and reused