7 USC 2531 - Ownership and assignment

(a) Subject to the provisions of this subchapter, plant variety protection shall have the attributes of personal property.
(b) Applications for certificates of plant variety protection, or any interest in a variety, shall be assignable by an instrument in writing. The owner may in like manner license or grant and convey an exclusive right to use of the variety in the whole or any specified part of the United States.
(c) A certificate of acknowledgment under the hand and official seal of a person authorized to administer oaths within the United States, or in a foreign country, of a diplomatic or consular officer of the United States or an officer authorized to administer oaths whose authority is proved by a certificate of a diplomatic or consular officer of the United States, shall be prima facie evidence of the execution of an assignment, grant, license, or conveyance of plant variety protection or application for plant variety protection.
(d) An assignment, grant, conveyance or license shall be void as against any subsequent purchaser or mortgagee for a valuable consideration, without notice, unless it, or an acknowledgment thereof by the person giving such encumbrance that there is such encumbrance, is filed for recording in the Plant Variety Protection Office within one month from its date or at least one month prior to the date of such subsequent purchase or mortgage.