A ripened ovule containing an embryo in arrested state of development usually with a food reserve and a protective coat.
Different Kinds of Seed:
Multiplication of quality seed under supervision of breeder or seed certification agency to distribute quality seed of notified varieties for sowing purpose.
Image Source: rdi.ku.ac.th
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(a) Nucleus Seed:
The true seed or vegetative propagules used for crop production and propagation are produced by the breeders. 100% gentically pure.
(b) Breeder’s Seed:
Progeny of Nucleus seed multiplied in larger area under the supervision of breeder.
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(c) Foundation seed:
Progeny of Breeder Seed.
It is handled by seed producing agencies in public and private sector under the supervision of Seed Certification Agencies (SCA).
SCA issues white colour certificate.
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(d) Certified Seed:
Progeny of Foundation Seed produced by registered seed growers under supervision of Seed Certification Agencies. SCA gives Blue colour certificate.
(e) Truthfuly labelled seed (TLS) minimum standard prescribed for the variety
(i) Production of Nucleus Seed
Basic Seed
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Sown in field with row to row and plant to plant spacing
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Plants are marked and observed
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Harvested Breeding of Nucleus Seed — Notification of variety
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Nucleus Seed (Bulk the seeds of selected rows)
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Breeders seed production plot
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Breeders seed
(ii) Production of Breeder seed
i. Nucleus seed is sown with less seed rate in line with all requirements.
ii. Roguing is complete before flowering
iii. Harvesting, threshing and processing
iv. Monitored by a team of breeder, representative of crop co-ordinator, representative of National Seed Corporation Agency
v. Quality of Processed Breeder seed is submitted to ICAR. Golden yellow certification is given.
(iii) Production of Foundation and Certified Seed
i. Foundation and certified seed produced under supervision of seed certification Agency.
ii. The grower get Breeder seed from seed corporation.
iii. Grower harvests, threshes and dries the seeds, lastly seeds transported to seed processing plant.
iv. Seed is processed under the observation of seed inspector.
v. Seed inspector submits a sample from the lot to seed testing lab..
Seed Dormancy:
Condition in a viable seed by which it prevents germination even under optimal conditions provided for germination.
Types of Seed dormancy:
Structural component of Seed:
Seeds cannot germinate until maturity of embryo is complete.
Physiological:
PH and osmotic pressure in the immediate environment of seed may act as inhibitors for germination.
Chemical: Inhibitors like phenols, Benzoic acids etc.
Breaking of Dormancy:
Scarification:
Physical or chemical treatment which weakens or softens seed coat.
Bitter gourd – Piercing with needle
Rubber – Removing the seed coat
Cotton – Soaking in conc H2S04 for 20-30 min.
Stratification (Temperature treatment) :
i. Pre chilling (0-5°C) for 3-10 days e.g. mustard.
ii. Pre heating (40-50°C) eg. Rice
iii. Hot water treatment – 80°C for 1 to 5 minutes.
Treatment with Growth Regulators and other chemicals
GA – For endogenous inhibitors
KN03 – For light requiring seeds – eg Tomato
Thiourea – For prechilling e.g. lettuce.