Science & Technology
Agricultural Science
Seed Technology and Crop Improvement
Varieties vs hybrids, the seed chain and tag colours, seed laws, biofortification, Bt cotton, GM mustard and India's genome-edited rice for CGPSC Mains GS-II.
Prerequisites
- Crop Science and Cropping Systems: crop physiology and the traits breeders try to improve
- Biotechnology: recombinant DNA and CRISPR basics, which this page applies to crops
- Green Revolution: the first big seed-led change in Indian farming
The Hook: 23,000 Rice Varieties in Raipur
Connect
In the 1970s, the rice scientist Dr R.H. Richharia (आर.एच. रिछारिया) walked the villages of Chhattisgarh and collected traditional rice varieties with names like Jeeraphool, Dubraj and Gathuan. Today Indira Gandhi Krishi Vishwavidyalaya (IGKV), Raipur holds a rice germplasm collection that is reported at over 23,000 accessions, among the largest held by any Indian university.
Why would a university guard thousands of “old” varieties when modern high-yielding ones exist? Because every new variety, whether made by crossing, by genetic modification or by genome editing, starts from genes found in such collections. Seed is where agricultural science begins.
Why it matters: Mains GS-II asks about GM crops, genome editing, biofortification and seed quality. These are favourite “examine the debate” questions. The topic also links to Interview questions on Bt cotton and seed shortages.
Variety, Hybrid and the Seed Chain
Variety vs hybrid
| Point | Variety (open-pollinated or pure line) | Hybrid (संकर) |
|---|---|---|
| How it is made | Selected and stabilised so plants breed true | First-generation (F1) cross of two genetically different parents |
| Farmer can save seed? | Yes: saved seed gives a similar crop | No (not usefully): saved F2 seed segregates and loses vigour |
| Yield | Good | Higher, from hybrid vigour (heterosis) |
| Seed cost | Low | High; must be bought every season |
| Examples | Most rice and wheat grown in India | Maize, cotton, many vegetables; hybrid rice on a smaller area |
The seed multiplication chain
Quality seed moves through generations. Each generation has its own tag colour:
| Class | Produced by | Tag colour |
|---|---|---|
| Nucleus seed | The breeder who developed the variety | No tag (handful of seed, genetically purest) |
| Breeder seed (प्रजनक बीज) | Breeder or institute (ICAR, state agricultural universities) | Golden yellow |
| Foundation seed (आधार बीज) | National and state seed corporations, from breeder seed | White |
| Certified seed (प्रमाणित बीज) | Seed producers, from foundation seed; checked by a seed certification agency | Azure blue |
| Truthfully labelled seed | Seller, under its own label | Opal green (not certified; the label is the seller’s claim) |
Seed Replacement Rate (SRR) is the share of area sown with fresh certified or quality seed instead of farm-saved seed. Higher SRR generally means better yields, because farm-saved seed loses purity and vigour over years. Hybrids need an SRR of 100% because their seed must be bought each season.
Seed processing science
Good seed means genetic purity (true to type), physical purity (no weed seed or inert matter), germination percentage, vigour and health (free of seed-borne disease). Seed treatment with fungicides or biological agents such as Trichoderma before sowing (बीजोपचार) is a cheap way to prevent seedling diseases.
How New Varieties Are Made: Breeding Methods
| Method | How it works | Indian example |
|---|---|---|
| Selection | Choose the best plants from a variable population | Early selections from local rice landraces |
| Hybridisation | Cross two parents and select in later generations (or use the F1 as a hybrid) | Semi-dwarf wheat and rice of the Green Revolution |
| Mutation breeding | Induce mutations with radiation or chemicals; select useful ones | Several groundnut and pulse varieties from BARC, Mumbai |
| Marker-assisted selection (MAS) | Use DNA markers linked to a trait to select plants early | Improved Samba Mahsuri, with bacterial blight resistance genes |
| Genetic modification (GM) | Insert a gene from another organism (transgenesis) | Bt cotton |
| Genome editing | Make precise changes to the plant’s own DNA, for example with CRISPR-Cas9 | DRR Dhan 100 (Kamala) and Pusa DST Rice 1 |
| Biofortification | Breed for higher nutrient content in the edible part | Chhattisgarh Zinc Rice-1; iron-rich pearl millet |
Biofortification: nutrition in the seed
Biofortification (जैव-पोषण संवर्धन) raises vitamins or minerals inside the crop through breeding, unlike fortification, which adds nutrients during processing (for example, fortified rice kernels mixed into PDS rice).
- Chhattisgarh Zinc Rice-1, developed at IGKV, Raipur, was released by the state variety release committee in 2015. It is widely reported as India’s first zinc-biofortified rice variety. The aim: fight zinc deficiency and malnutrition in the state’s tribal belt.
- Other Indian examples include iron-rich pearl millet and zinc-rich wheat varieties released by ICAR.
Why biofortification suits Chhattisgarh: the poorest households eat mostly rice, so putting zinc into the rice they already grow and eat reaches them without new supply chains.
GM Crops in India
Regulation
- GM organisms are regulated under the Environment (Protection) Act, 1986 and the Rules, 1989 made under it.
- The approving body is the Genetic Engineering Appraisal Committee (GEAC) (जेनेटिक इंजीनियरिंग मूल्यांकन समिति) in the Ministry of Environment, Forest and Climate Change.
The record so far
| Crop | Status |
|---|---|
| Bt cotton | Approved in 2002. It carries cry genes from the soil bacterium Bacillus thuringiensis, which make a protein toxic to bollworms. It is the only GM food or fibre crop in wide commercial cultivation in India |
| Bt brinjal | GEAC cleared it in 2009, but the government placed an indefinite moratorium in February 2010. Bangladesh grows Bt brinjal |
| GM mustard (DMH-11) | Developed at Delhi University using the barnase–barstar system to make hybrid seed production easy. GEAC approved its environmental release in October 2022. In July 2024 a two-judge Supreme Court bench gave a split verdict and directed the Centre to frame a national policy on GM crops. Its commercial future remained unsettled (as of 2026) |
Bt cotton: the evidence both ways
Gains: Cotton output and yields rose sharply in the 2000s, and insecticide spraying against the American bollworm fell.
Problems: Pink bollworm developed resistance to Bt cotton (including two-gene Bollgard II) in the 2010s. Farmers did not plant enough non-Bt refuge rows, which are meant to slow resistance. Sucking pests not controlled by Bt toxins rose. Seed prices and royalties became political issues. Illegal herbicide-tolerant (HT) Bt cotton spread without approval.
In a Mains answer, present Bt cotton as a real but eroding gain that shows why resistance management matters.
Genome editing: a different category
- CRISPR-Cas9 (क्रिस्पर) cuts DNA at a chosen site. The cell’s repair makes a small change (SDN-1) or a template-guided change (SDN-2). SDN-3 inserts a larger new gene, which is close to transgenesis.
- In March 2022, the Ministry of Environment exempted SDN-1 and SDN-2 genome-edited plants, which carry no foreign DNA, from the GM biosafety rules (Rules 7–11 of the 1989 Rules). They are treated more like conventionally bred varieties.
- In May 2025, ICAR announced India’s first two genome-edited rice varieties:
| Variety | Institute | Parent variety | Trait |
|---|---|---|---|
| DRR Dhan 100 (Kamala) | ICAR–Indian Institute of Rice Research, Hyderabad | Samba Mahsuri | Higher yield, matures about 15–20 days earlier |
| Pusa DST Rice 1 | ICAR–Indian Agricultural Research Institute, New Delhi | Cotton Dora Sannalu (MTU 1010) | Drought and salinity tolerance |
ICAR described this as a world first for genome-edited rice varieties. Critics questioned the exemption from biosafety review and asked for long-term field data.
Seed Laws and Farmers’ Rights
| Law or instrument | Key point |
|---|---|
| Seeds Act, 1966 | Regulates the quality of notified varieties offered for sale; set up seed certification. Registration of varieties is not compulsory under it |
| Seeds (Control) Order, 1983 | Issued under the Essential Commodities Act; licensing of seed dealers |
| Protection of Plant Varieties and Farmers’ Rights (PPV&FR) Act, 2001 | India’s sui generis system under the WTO TRIPS Agreement. It protects breeders’ rights and, unusually, farmers’ rights: a farmer may save, use, sow, re-sow, exchange, share and sell farm produce including seed, but not as branded seed of a protected variety. Farmers can also register their own varieties |
| PPV&FR Authority | Set up under the 2001 Act; registers varieties and recognises farmer conservers |
| Draft Seeds Bill, 2025 | Released for public comment in November 2025 to replace the 1966 Act and the 1983 Order, with mandatory registration and higher penalties for spurious seed. Not enacted as of late 2026; consultations were continuing |
Chhattisgarh angle
- IGKV, Raipur keeps one of India’s largest rice germplasm collections, much of it collected by Dr R.H. Richharia in the 1970s. This collection is the state’s genetic insurance against disease and climate change.
- Chhattisgarh Zinc Rice-1 (2015) puts the state on the biofortification map.
- Seed shortages and spurious seed at sowing time are a recurring complaint in the state’s cooperative societies, which is why seed quality laws matter to its farmers.
- Traditional aromatic rices such as Jeeraphool and Nagri Dubraj carry GI tags (see Rice Bowl of India). Conserving such landraces is both a heritage and a breeding resource.
Memory Tricks
Seed tag colours: 'Gold, White, Blue, Green'
Think of a medal ceremony that ends in a field: Golden yellow (breeder) → White (foundation) → Blue (certified) → Green (truthfully labelled). Purest at the top, most plentiful at the bottom.
Genome editing grades: 'Snip, Swap, Stuff'
SDN-1 = snip (small change by natural repair) · SDN-2 = swap (template-guided edit) · SDN-3 = stuff (insert a whole new gene). India exempted only snip and swap.
Don’t Confuse
| This | vs | That |
|---|---|---|
| Biofortification: nutrient bred into the crop (Zinc Rice-1) | vs | Fortification: nutrient added during processing (fortified rice kernels) |
| GM / transgenic: foreign gene inserted (Bt cotton) | vs | Genome-edited SDN-1/2: own genes changed, no foreign DNA (Kamala) |
| GEAC: under the Environment Ministry, approves GM release | vs | PPV&FR Authority: under the Agriculture Ministry, registers varieties and protects rights |
| Foundation seed: white tag | vs | Certified seed: azure blue tag |
| Bt brinjal: moratorium since 2010 | vs | GM mustard: environmental release approved 2022, then split Supreme Court verdict 2024 |
Common Mistakes
MCQ and Mains traps
- “Farmers cannot save seed of a protected variety under the PPV&FR Act.” False. They can save, use, exchange and sell it, but not as branded seed.
- “GEAC is under the Ministry of Agriculture.” False. It is under the Ministry of Environment, Forest and Climate Change.
- “India’s genome-edited rice is GM rice.” Misleading. The two varieties are SDN-1 edits with no foreign DNA, exempted from GM rules in 2022.
- “Hybrid seed can be saved and re-sown.” It can be sown, but the next generation segregates and loses hybrid vigour.
- “Bt cotton is resistant to all pests.” False. Bt toxins target bollworms; sucking pests are unaffected, and pink bollworm has evolved resistance.
Practice
All questions below are original practice questions written in CGPSC style. They are not previous-year questions.
Level 1: Foundation
- The tag colour of certified seed is ______.
- The bacterium whose genes give Bt cotton its insect resistance is ______.
- India’s first zinc-biofortified rice variety, developed at IGKV Raipur, is ______.
Answers
- Azure blue.
- Bacillus thuringiensis.
- Chhattisgarh Zinc Rice-1 (released 2015).
Level 2: Prelims-style MCQs
Q1. Consider the following statements:
- The Genetic Engineering Appraisal Committee functions under the Ministry of Environment, Forest and Climate Change.
- SDN-1 and SDN-2 genome-edited plants without foreign DNA have been exempted from India’s GM biosafety rules.
- Bt brinjal is approved for commercial cultivation in India.
Which of the statements given above is/are correct?
- (a) 1 only
- (b) 1 and 2 only
- (c) 2 and 3 only
- (d) 1, 2 and 3
Answer and explanation
(b) 1 and 2 only. GEAC sits in the Environment Ministry. The March 2022 exemption covers SDN-1 and SDN-2 edits that carry no exogenous DNA. Bt brinjal has been under a moratorium since February 2010, so statement 3 is wrong.
Q2. Match List I (Seed class) with List II (Tag colour):
| List I | List II |
|---|---|
| A. Breeder seed | 1. White |
| B. Foundation seed | 2. Azure blue |
| C. Certified seed | 3. Opal green |
| D. Truthfully labelled seed | 4. Golden yellow |
- (a) A-4, B-1, C-2, D-3
- (b) A-1, B-4, C-2, D-3
- (c) A-4, B-2, C-1, D-3
- (d) A-4, B-1, C-3, D-2
Answer and explanation
(a) A-4, B-1, C-2, D-3. Breeder seed carries a golden yellow tag, foundation seed white, certified seed azure blue and truthfully labelled seed opal green.
Q3. A farmer saves seed from his hybrid maize crop and sows it the next year. The most likely result is:
- (a) The same yield, because the genes are unchanged
- (b) Higher yield, because the seed has adapted to the farm
- (c) An uneven crop with lower yield, because the next generation segregates
- (d) No germination, because hybrid seed is sterile
Answer and explanation
(c). Hybrid vigour is strongest in the F1. Saved F2 seed segregates into varied plant types and loses heterosis. Hybrid seed is not sterile, so (d) is wrong. This is why hybrid seed must be bought each season.
Q4. Under the Protection of Plant Varieties and Farmers’ Rights Act, 2001, a farmer is entitled to:
- (a) Sell branded seed of a protected variety
- (b) Save, use, exchange and sell farm produce including seed, but not as branded seed of a protected variety
- (c) Use protected varieties only after paying a royalty
- (d) Register only varieties developed by ICAR
Answer and explanation
(b). The Act explicitly preserves the farmer’s traditional right to save, use, sow, re-sow, exchange, share and sell produce including seed. The only bar is selling it as branded seed of a protected variety. Farmers can also register their own varieties.
Level 3: Mains Answer Writing
Q1. (60 words) Distinguish biofortification from fortification with one example of each.
Model answer outline
- Biofortification: breeding (or biotechnology) raises nutrient levels in the growing crop. Example: Chhattisgarh Zinc Rice-1 (IGKV Raipur, 2015).
- Fortification: nutrients added during processing. Example: fortified rice kernels in PDS rice, iodised salt.
- Biofortification is a one-time research cost that reaches rural households through their own seed; fortification needs a processing and supply chain.
Q2. (150–200 words) “Genome editing is not genetic modification.” Examine this claim in the context of India’s genome-edited rice varieties.
Model answer outline
- Intro: In May 2025 ICAR announced DRR Dhan 100 (Kamala) and Pusa DST Rice 1, developed with CRISPR-Cas9.
- Why the claim holds:
- SDN-1 and SDN-2 edits change the plant’s own genes and leave no foreign DNA, unlike transgenic Bt cotton.
- Such changes can in principle arise through natural mutation or mutation breeding.
- India’s 2022 exemption from GM rules follows this reasoning; several other countries treat such edits similarly.
- Why critics disagree:
- Off-target edits and long-term ecological effects need study.
- Exemption removes the GEAC biosafety review and labelling debates.
- Concerns about patents on CRISPR tools and corporate control of seed.
- Benefits for states like Chhattisgarh: faster breeding for drought tolerance and shorter duration in rainfed rice; a shorter crop frees soil moisture for utera pulses.
- Conclusion: The scientific distinction is real, but trust needs transparent field data, monitoring and farmer access at fair cost.
Quick Revision Table
| Fact | Detail |
|---|---|
| Seed chain | Nucleus → breeder (golden yellow) → foundation (white) → certified (azure blue); truthfully labelled (opal green) |
| Hybrid | F1 of two parents; heterosis; buy fresh each season |
| Seeds Act | 1966; quality of notified varieties |
| PPV&FR Act | 2001; breeders’ and farmers’ rights; TRIPS sui generis |
| Draft Seeds Bill | 2025; to replace 1966 Act; not enacted as of late 2026 |
| GM regulator | GEAC, Environment Ministry; EP Act 1986 + Rules 1989 |
| Bt cotton | Approved 2002; Bacillus thuringiensis cry genes |
| Bt brinjal | Moratorium Feb 2010 |
| GM mustard DMH-11 | Environmental release Oct 2022; split SC verdict July 2024 |
| Genome-editing exemption | March 2022; SDN-1 and SDN-2 |
| Genome-edited rice | May 2025: DRR Dhan 100 (Kamala), Pusa DST Rice 1 |
| Zinc rice | Chhattisgarh Zinc Rice-1, IGKV Raipur, 2015 |
| Rice germplasm | IGKV Raipur, over 23,000 accessions; Dr R.H. Richharia’s collections |
Key Takeaways
Key Takeaways
- Varieties breed true and can be saved; hybrids give heterosis but need fresh seed every season.
- Quality seed moves nucleus → breeder → foundation → certified, each with a fixed tag colour.
- GM crops (transgenic) are regulated by GEAC; SDN-1 and SDN-2 genome edits were exempted in 2022.
- Bt cotton shows both the promise of GM and the danger of pest resistance.
- IGKV Raipur’s germplasm and zinc rice give Chhattisgarh a strong seed-science story for Mains.
What’s Next
- Soil Fertility, Fertilisers and Manures: what the improved seed needs from the soil
- Pest Management and IPM: resistance management for Bt crops
- Biotechnology: the tools (rDNA, CRISPR) in more depth
- Biodiversity and Conservation: germplasm conservation and seed banks
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