CLASSES OF SEED
WHAT IS SEED?
In broad sense, seed is a material which is used for planting or regeneration purpose, i.e. part of agriculture, sericulture, silviculture and horticultural plants used for sowing or planting purpose. Seed may be structurally defined as a fertilized matured ovule, consisting of an embryonic plant, a store of food and a protective seed coat, a store of food consists of cotyledons and endosperm. However, from the seed technological point of view, seed may be sexually produced matured ovule consisting of an intact embryo, endosperm and or cotyledon with protective covering (seed coat). It also refers to propagating materials of healthy seedlings, tuber, bulbs, rhizome, roots, cuttings, setts, slips, all types of grafts and vegetatively propagating materials used for production purpose and it is a link between two generations.
Four main classes of seeds are defined by the Association of Official Seed Certification Agency. They are:
(1) Nucleus Seed
(ii) Breeder Seed
(iii) Foundation Seed
(iv) Certified See
(I) Nucleus Seed
Nucleus seeds are the initial amount of pure seed of improved variety or notified variety or parental lines of a hybrid produced under the supervision of the evolver of the variety. It is the basic seed class for seed production. These seeds are maintained by the breeder for further multiplication. It is produced under the direct supervision of the concerned plant breeder. It is produced based on the various crop multiplication techniques and methods. Nucleus seeds possess high percentage of genetic purity (100%) and do not contain any physical impurities. It is produced under isolation to avoid both genetical and physical impurities. Nucleus seed should retain original vigour of the variety or parental line. No tag is used for nucleus seed.
(ii) Breeder Seed
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| Breeder seed |
Breeder seeds are the progeny of nucleus seed. It is produced in the Research institutes or Universities under the supervision of a breeder. The entire production process will be monitored by the Scientists and Officers of the Seed Certification Department and by the representatives of the National Seed Corporation. The genetic purity of the breeder seeds is 99.99 to almost 100%. The physical purity is 98% or more, germination as per crop and moisture content less than 12%. Generally breeder seed is produced in one stage. But if there is greater demand for breeder seed and there is low seed multiplication ratio then breeders seed can be produced in two stages, viz. Breeder seed stage I and II. In such cases, breeder seed stage I becomes source for breeder seed Stage II.
Seeds are distributed in bags with golden yellow colour tag provided by the breeder. The tag size is 12 cm x 6 cm.
Also Read : Cultivation of Black Gram
(iii) Foundation Seed
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| Foundation seed |
Foundation seeds are produced from the breeder seeds. It can be produced in two stages viz. Stage I and Stage II. It is produced at Government farms, Research institutes or Universities or by private seed producers. Its production can also be taken up by the farmers by getting suitable breeder seeds. Foundation seed is the source of all other certified seed classes, either directly or through registered seed. Genetic purity of the foundation seeds 99% or more and its certification tag is white in colour of size 15 cm x 7.5 cm. The tag is supplied by the certification agency after certification and the production must be acceptable by the certification agency.
(iv) Registered Seed
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| Registered seed |
It is the progeny of foundation seed produced by the progressive farmers or registered seed growers according to the technical guidance and supervision of National Seed Corporation (NSC). It is inspected by representative of seed certification agencies. Seeds are stored in purple color tags. At present this class of seed is not produced in seed chain.
(v) Certified Seed
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| Certified seed |
Seeds produced from foundation seeds are known as certified seeds. The production of certified seeds is taken up by the National and State Seed Corporation, private seed companies and also by farmers. The certified seeds should possess uniformity and purity as defined by the Department of Seed Certification. In case of self pollinated crops, certified seeds can also be produced from certified seeds provided it does not go beyond three generations from foundation seed stage-I. The genetic purity of the certified seeds is 98% or more and the certification tag provided is azure blue in colour of size 15 cm x 7.5 cm.
Also Read : Cultivation of Black Gram
Reference : A text book on principles of seed technology ; Kalyani Publishes