When used in conjunction with or in reference to seed organisms, the following shall mean:

(a) Master Seed. An organism at a specific passage level which has been selected and permanently stored by the producer from which all other seed passages are derived within permitted levels.

(b) Working Seed. An organism at a passage level between Master Seed and Production Seed.

(c) Production Seed. An organism at a specified passage level which is used without further propagation for initiating preparation of a fraction.