The legal act that sets the basis for the protection of plant varieties at international level is the International Convention for the Protection of New Varieties of Plants (UPOV).
The 1991 version of the UPOV Convention is in force in most countries, whereas the 1978 UPOV continues to have legal effects in few countries. For the UPOV Members see http://www.upov.int/upovlex/en/notifications.jsp
2. Other international acts
Other legal acts that influence the application of plant variety rights are the Trade Related Intellectual Property Rights Agreement (TRIPS), the Convention on Biological Diversity (CBD), the Nagoya Protocol implementing art. 15 of the CBD and the International Treaty on Plant Genetic Resources for Food and Agriculture (ITPGRFA). Trade agreements influence PVP to the extent that they impose obligations on plant variety rights.
3. National instruments
EU: Council Regulation (EC) No 2100/94 of 27 July 1994 on Community plant variety rights (EC 2100/94) & the European Patent Convention (EPC) for plant varieties that incorporate patented genetic sequences
US: everything under the sun is patented.
1. The Plant Patent Act (PPA) of 1930 (for asexually propagated plants); 2. Plant Variety Protection Act (PVPA) of 1970 (for seed propagated plants); 3. Section 101 of the Patent Act (asexually and sexually propagated plants, parts of plants, seeds, etc).
Other countries that provide patent protection for plant varieties are Australia & Japan. To be noted, that in EU countries patent protection extends to plant varieties when patented genetic sequences are embedded in the variety. Australia & Japan also provide for breeders’ rights when varieties are distinct, uniform, and stable.