PB Ch 1, History of Plant Breeding

HISTORY OF PLANT BREEDING

• Plant breeding is one of the oldest activities of mankind, yet it remains the most powerful tool for improving agriculture. 
• From the moment early humans selected the best-looking seeds to replant, they were unknowingly practising plant breeding. 
• Today it is a rigorous science that draws from genetics, cytology, molecular biology, statistics, and biotechnology to reshape the genetic architecture of crops.
• Plant Breeding (N.W. Simmonds, 1979): The science of changing the genetic architecture of plants to serve the needs of humankind. Also called crop improvement — it is the current phase of crop evolution directed by human intelligence.

Several complementary definitions are given in textbooks and may be quoted in answers:

• Art, Science and Technology: Plant breeding is the art, science and technology of improving the genetic make-up of plants in relation to their economic use for mankind. (GPBR 211, BAU)
• Genetic improvement definition: The science of changing and improving the heredity of plants.
• Practical definition: Deliberate effort by humans to improve the genetic potential of crop plants for yield, quality, or adaptation.

Why Plant Breeding Matters

• India feeds 1.4 billion people on ~141 million hectares of net sown area.
• Every major crop yield increase since 1960 has been delivered primarily by improved varieties — not just by more fertiliser or irrigation.
• The Green Revolution (1966–70) doubled wheat output without adding a single hectare. Plant breeding is the most cost-effective investment in food security

1.1 Objectives of Plant Breeding

The objectives of plant breeding are not fixed — they shift with economic needs, ecological pressures, and consumer preferences. The following objectives are universally recognised:

A. Increased Yield

• The ultimate aim. Yield improvement can be achieved by developing high-yielding varieties (HYVs) or hybrids with better harvest index, more tillers, more grains per ear, heavier grains, or more efficient photosynthesis.
• Examples: Semi-dwarf wheat varieties (Kalyan Sona, HD 2967) increased yield from ~1 t/ha to 3.5 t/ha; IR-8 rice demonstrated 5–10 t/ha potential.
• Harvest Index: HYVs have higher harvest index (0.45–0.55) vs tall traditional varieties (0.30–0.35). Green Revolution success was largely due to improved HI through dwarfing genes.

B. Improved Quality

• Quality characters vary with crop and end-use. They include:
• Cereals: Grain size, colour, milling yield, baking quality (gluten content in wheat), cooking quality, aroma (2-acetyl-1-pyrroline in basmati rice), malting quality in barley.
• Pulses: Protein content, sulphur-containing amino acid profile (methionine, cysteine), cooking time, digestibility.
• Oilseeds: Oil content, fatty acid composition — low erucic acid in mustard (canola-type), high oleic acid in sunflower.
• Cotton: Fibre length, strength, fineness (micronaire), uniformity ratio.
• Vegetables/Fruits: Total soluble solids (TSS), vitamin C, lycopene (tomato), shelf life, post-harvest quality.

C. Biotic Stress Resistance

• Crop plants are attacked by fungi, bacteria, viruses, nematodes and insects. Genetic resistance is cheaper, more sustainable and more durable than pesticide use.
• Diseases: Wheat rust (Sr, Lr, Yr genes), rice blast (Pi genes), bacterial blight (Xa genes), late blight of potato.
• Insects: Brown plant hopper in rice (Bph1, bph2 genes), stem borer, bollworm (addressed through Bt gene in cotton).
• Nematodes: Root-knot nematode resistance in tomato (Mi gene from wild Lycopersicon peruvianum).

D. Abiotic Stress Tolerance

• With climate change intensifying, abiotic stress tolerance has become a priority objective.
• Drought tolerance: Deep root systems, osmotic adjustment, stay-green trait, early maturity for drought escape. E.g., Sahbhagi Dhan (IRRI), DRR Dhan 42.
• Salinity tolerance: Ion exclusion (HKT1;5 transporter), compartmentation (NHX1 vacuolar antiporter). E.g., CST 7-1 rice, Saltol QTL from Pokkali.
• Heat tolerance: Membrane stability, pollen viability at high temperatures. E.g., HD 3086 wheat.
• Submergence tolerance: Swarna-Sub1 (Sub1A gene from FR13A landrace, transferred via MABC).
• Cold tolerance: Vivek 64 maize (VPKAS Almora), VL Dhan 61 rice.

E. Earliness and Change in Maturity Duration

• Early maturity offers several agronomic advantages. It requires a shorter crop management period, permits new crop rotations, requires fewer insecticidal sprays, and extends the crop area into new regions.
• Quantitative examples (from GPBR 211 source): Maturity reduced from 270 → 170 days in cotton; from 270 → 120 days in pigeonpea (Asha variety); from 360 → 270 days in sugarcane. These are cited in the source material — please verify current figures from ICAR publications.

F. Other Important Objectives

• Determinate growth: Desirable in pulses (mung, pigeonpea) and cotton — allows uniform maturity and mechanical harvest.
• Dormancy modification: Introducing dormancy prevents pre-harvest germination in greengram, blackgram, barley, pea. Removing excessive dormancy desirable in groundnut.
• Non-shattering: Pod shattering in greengram, Brassica causes yield loss; resistance to shattering is a breeding objective.
• Synchronous maturity: Important in crops with indeterminate flowering (cotton, cowpea, greengram) where multiple pickings are needed.
• Photo and thermoinsensitivity: Varieties insensitive to day length and temperature can be grown across latitudes and seasons. E.g., IRRI's short-duration rice varieties; wheat now grown in West Bengal; rice grown in Punjab.
• Wider adaptability: Variety suitable for diverse environments stabilises crop production across regions and seasons.
• Elimination of toxic substances: Neurotoxin (ODAP/BOAA) from khesari (Lathyrus sativus); erucic acid from Brassica; gossypol from cottonseed; cucurbitacin from cucurbits; HCN from sorghum.
• Varieties for new seasons: Maize traditionally kharif but now grown as rabi and zaid; mung now as summer crop.

1.2 Scope of Plant Breeding

• The scope of plant breeding has expanded enormously, from selecting within existing variation to engineering genes across kingdoms. Key dimensions of scope include:
• Classical breeding: Hybridization, selection (pure line, mass, pedigree, bulk, backcross, recurrent) — still the backbone of crop improvement worldwide.
• Quantitative genetics: Statistical tools to analyse polygenic traits, estimate heritability, predict genetic advance, map QTLs.
• Biotechnology integration: Molecular markers (RFLP, SSR, SNP) for marker-assisted selection; tissue culture for doubled haploids; Agrobacterium and gene gun for transgenics; CRISPR-Cas9 for precision genome editing.
• Wide hybridization: Exploiting genes from wild relatives and distant species via embryo rescue, chromosome doubling, somatic hybridization.
• Climate-smart breeding: Heat, drought, flood and salinity tolerance to ensure food security under climate change.
• Biofortification: Enhancing nutritional content (Zn, Fe, beta-carotene, protein quality) to address hidden hunger.

Undesirable Effects of Plant Breeding 

Plant breeding, while highly beneficial, also has documented negative consequences.

• Reduction in Diversity: Modern improved varieties are genetically uniform; they are more vulnerable to new pathogen races than genetically diverse landraces.
• Narrow Genetic Base: Uniform varieties have poor adaptability and are susceptible to genetic vulnerability. E.g., T-cytoplasm in maize made entire US crop susceptible to Southern Corn Leaf Blight (Helminthosporium maydis race T) in 1970, causing 15–20% yield loss.
• Danger of Uniformity: Most improved varieties share common parents in their pedigree, creating genetic uniformity across vast areas.
• Undesirable Combinations: Plant breeding sometimes produces man-made crops with undesirable characters, e.g., Raphanobrassica (combines radish root with cabbage leaf — neither agronomically useful) and Pomato (potato+tomato hybrid).
• Increased susceptibility to minor pests: Emphasis on resistance to major diseases can inadvertently increase susceptibility to minor ones. Examples from source: Botrytis cinerea (grey mould) epidemic in chickpea during 1980–82 in Punjab and Haryana; Karnal bunt (Tilletia sp.) on certain wheat varieties; mealy bug infestation in Bt cotton (sucking pests not covered by Bt toxin).
• Genetic erosion: Introduction of HYVs displaces traditional landraces. E.g., introduction of IR-20 rice led to disappearance of many Samba rice landraces in Tamil Nadu (cited in GPBR 211 AGRIGNAN source).
• Yield plateau: After rapid initial gains, yield improvements have plateaued in major cereals. The yield ceiling of wheat and rice is being approached, requiring new approaches like genomic selection and speed breeding.

PYQ 

• IFoS 2025 (Q2a, 15M): Write the various phases of history of plant breeding and describe the importance of genetic engineering phase. 
• CSE 2016 (Q2a, 10M): Write on the contribution of Norman Borlaug to wheat improvement and Green Revolution. 
• CSE 2017 (Q2a, 10M): Describe the history of plant breeding in India — from domestication to modern era. 
• CSE 2018 (Q2a, 10M): Write on M.S. Swaminathan's contribution to Indian agriculture. 
• CSE 2020 (Q2a, 10M): Write on milestones in plant breeding — hybrid maize, dwarf wheat, IR-8 rice. 
• CSE 2023 (Q2a, 10M): Discuss the evolution of crop breeding from selection to genomic selection.

1.3 Five Phases of History of Plant Breeding

The history of plant breeding is conventionally divided into five distinct phases based on the scientific knowledge available and the methods used. Every UPSC answer on this topic should cover all five phases with key scientists, their contributions, and the year.

PHASE I — DOMESTICATION ERA (~10,000 BC to ~1700 AD) : This phase covers the entire period from when humans first deliberately cultivated plants until the dawn of scientific hybridization. It is the longest phase, spanning approximately 12,000 years.

• Nature of breeding: Unconscious selection — farmers saved seeds from the best-looking, highest-yielding, tastiest plants without understanding genetics.
• Domestication syndrome: Over millennia, unconscious selection resulted in loss of seed shattering, increased grain size, loss of dormancy, synchronous flowering, reduced bitterness and toxicity, and loss of seed dispersal mechanisms.
• Origin of agriculture: ~10,000 BC in the Fertile Crescent (wheat, barley, lentil); ~7,000 BC in China (rice, millet, soybean); ~5,000 BC in Meso-America (maize, bean, squash); Andes (potato, quinoa, tomato).
• 700 BC: Babylonians and Assyrians artificially pollinated the date palm — earliest documented case of controlled pollination.
• 17th century: Several varieties of heading lettuce developed in France through deliberate selection.
• 1717: Thomas Fairchild (England) produced the first documented artificial plant hybrid, popularly known as 'Fairchild's Mule', by crossing carnation (Dianthus caryophyllus) with Sweet William (D. barbatus). This is also the first documented case of distant hybridization.
• 1727: The first plant breeding company was established in France by the Vilmorins.
• No scientific basis: Yet this phase produced virtually all cultivated crop species used today. It represents the most sustained and successful breeding programme in human history.

PHASE II — PRE-MENDELIAN ERA (1700–1900) : This phase is marked by the first systematic scientific experiments in plant hybridization and selection, even without an understanding of the laws of inheritance. The foundations for scientific breeding were laid here.

• Camerarius (1694): Discovered sex in plants; demonstrated that pollen is necessary for seed production. His work on Mercurialis and Spinach established the role of male and female organs.
• Joseph Koelreuter (1760–1766): German botanist who made extensive crosses in tobacco (Nicotiana) and Solanum; studied hybrids in detail. Regarded as a founder of scientific hybridization. Studied F1 vigour and F2 segregation long before Mendel.
• Thomas Andrew Knight (1759–1835): First person to use artificial hybridization systematically to develop improved fruit varieties (peas, apples). His work on peas included observations on dominance — he may have observed what Mendel later explained, but did not document it clearly.
• Le Couteur (1843): A farmer who published results on individual plant selection in wheat; concluded that progenies from single plants were more uniform — an early grasp of the pure line concept.
• Patrick Shirreff (1873): Scottish farmer who practiced individual plant selection in wheat and oats; developed valuable varieties. Concluded that only heritable variation responded to selection, and that variation arose through 'natural sports' (mutations) and 'natural hybridization' (recombination).
• Vilmorin (1856–1857): Developed and applied the progeny test (Vilmorin's principle of progeny testing) — individual plants selected and their progeny evaluated. Successfully applied to sugar beet improvement; demonstrated the ineffectiveness of mass selection in cross-pollinated crops where progeny cannot be predicted from phenotype alone.
• Charles Darwin (1859): Origin of Species; theory of natural selection and concept of variation. While Darwin did not understand inheritance mechanistically, his work provided the conceptual framework for understanding how selection acts on variation.
• Nilsson-Ehle and Associates (Svalof, Sweden, 1890–1900): Refined individual plant selection; developed the bulk method (credited to Nilsson and Ehle). Their work at the Swedish Seed Association (Svalof) produced many practical cereal varieties.

PHASE III — MENDELIAN / REDISCOVERY ERA (1900–1930) : The rediscovery of Mendel's laws in 1900 transformed plant breeding from empirical art to a science with a theoretical foundation. This phase saw the rapid application of Mendelian genetics to crop improvement.

• Gregor Mendel (1822–1884): Conducted experiments on garden pea (Pisum sativum) at Augustinian monastery in Brno (Czech Republic) from 1856–1863; published his laws of inheritance in 1865 in 'Versuche über Pflanzen-Hybriden' (Experiments in Plant Hybridization). His paper was ignored for 35 years.
• Rediscovery of Mendel (1900): Hugo de Vries (Netherlands), Carl Correns (Germany) and Erich von Tschermak (Austria) independently rediscovered Mendel's laws in 1900 while working on their own hybridization studies.
• Johannsen (1903): Proposed the pure line theory based on his work with Princess variety of common bean (Phaseolus vulgaris). Showed that a market lot consists of a mixture of pure lines, each homozygous and true-breeding, and that variation within a pure line is environmental and non-heritable. Introduced the terms 'genotype' and 'phenotype'. This provided the genetic basis for individual plant selection in self-pollinated crops.
• Nilsson-Ehle (1908): Demonstrated multiple factor / polygene concept using kernel colour in wheat (red vs white) — three independent genes each with incomplete dominance gave continuous variation, explaining quantitative inheritance through Mendelian genes.
• G.H. Shull (1908) and E.M. East (1908): Independently described heterosis (hybrid vigour) in maize. Shull formally coined the term 'heterosis' in 1914. Their work laid the foundation for hybrid maize breeding.
• Hardy-Weinberg Equilibrium (1908): G.H. Hardy (mathematician) and W. Weinberg (physician) independently derived the principle that allele and genotype frequencies remain constant in an ideal population (large size, random mating, no selection, no mutation, no migration). Provided the theoretical foundation for population genetics.
• Thomas Hunt Morgan (1910): Discovered sex linkage and demonstrated Mendelian inheritance in Drosophila. Established chromosome theory of inheritance. Work by Bridges, Sturtevant and Muller extended to gene mapping.
• Donald F. Jones (1917, 1922): Proposed the double-cross hybrid method for commercial maize; overcame the problem that single-cross hybrids were too costly to produce commercially because inbred lines had low seed yield.

PHASE IV — POPULATION GENETICS & QUANTITATIVE ERA (1930–1960) : This phase saw the mathematical formalisation of genetics and the application of statistical methods to breeding. It produced the theoretical tools still used today in quantitative genetics, and the practical tools that underpinned the Green Revolution.

• R.A. Fisher (1918, 1930): Applied biometrics to genetics; partitioned phenotypic variance into additive, dominance and epistatic components. Laid the foundation for quantitative genetics and the estimation of heritability. His 'The Genetical Theory of Natural Selection' (1930) unified Mendelian genetics and Darwinian evolution.
• Sewall Wright (1921–1931): Developed path coefficient analysis and mathematical models of random genetic drift; concept of effective population size; inbreeding coefficients. Introduced the idea of adaptive landscapes.
• J.B.S. Haldane (1924–1932): Mathematical treatment of selection and mutation in populations. Together, Fisher, Wright and Haldane created the 'Modern Synthesis' unifying genetics and evolution.
• Lewis J. Stadler (1928): First experimentally induced mutations using X-rays in maize and barley, building on de Vries' mutation theory. He also used UV light. This opened the field of mutation breeding.
• N.I. Vavilov (1926, 1935): Published 'Studies on the Origin of Cultivated Plants' (1926) proposing 8 Centres of Origin; formulated the Law of Homologous Series in Variation (1922). Built the world's largest seed collection at the time at VIR (Vavilov Institute, St. Petersburg).
• Sprague and Tatum (1942): Introduced the concepts of General Combining Ability (GCA) and Specific Combining Ability (SCA) — these remain the cornerstone of hybrid breeding strategy. GCA reflects additive genetic variance; SCA reflects non-additive (dominance + epistasis) variance.
• Comstock, Robinson & Harvey (1949): Developed Reciprocal Recurrent Selection (RRS) — the most comprehensive population improvement scheme that exploits both additive and non-additive variance simultaneously.
• E.R. Sears (1950s): Developed monosomic series in wheat (Chinese Spring) — 21 monosomics corresponding to 21 chromosome pairs. Enabled systematic gene assignment to specific chromosomes. Foundation for wheat cytogenetics.
• Hull (1945): Proposed Recurrent Selection for Specific Combining Ability (RSSCA) to improve combining ability of populations.
• Jenkins (1940): Proposed Recurrent Selection for General Combining Ability (RSGCA).
• Harlan and Pope: Developed the backcross method of plant breeding as a systematic procedure.
• Goulden (1939): Proposed the Single Seed Descent (SSD) method for rapid advancement of generations in self-pollinated crops.
• Blackslee and Nebel (1937): Developed the colchicine method for inducing polyploidy — opened up the practical exploitation of allopolyploidy in crop improvement.

PHASE V — MOLECULAR / BIOTECHNOLOGY ERA (1960 onwards) : This phase is defined by the application of molecular biology tools to plant breeding. It began with the discovery of the DNA double helix (1953) and has culminated in CRISPR genome editing (2012). IFoS 2025 specifically asked about the importance of this phase.

• Watson & Crick (1953): Proposed the double-helix model of DNA structure. This is the scientific foundation of the entire molecular era. All subsequent molecular tools trace back to understanding DNA structure.
• Norman Borlaug (1960s): Developed semi-dwarf wheat varieties at CIMMYT (Mexico) incorporating Norin-10 dwarfing genes (Rht1, Rht2) from Japanese wheat. This triggered the Green Revolution. Awarded Nobel Peace Prize in 1970. I believe this to be accurate but please verify the year of Nobel Prize from official sources.
• Murashige & Skoog (1962): Developed the MS medium for plant tissue culture, enabling the growth of plant cells and organs on defined nutrient medium. Foundation of all tissue culture-based breeding techniques.
• Guha & Maheshwari (1964): Produced the first anther-derived haploid plants from Datura (thorn apple) using anther culture. This opened the field of doubled haploid breeding.
• Cohen & Boyer (1973): Produced the first recombinant DNA molecule by combining genes from different organisms. Birth of genetic engineering. This is the event that formally began the transgenic era.
• Development of RFLP markers (Botstein et al., 1980): First DNA-based molecular markers (Restriction Fragment Length Polymorphism). Enabled construction of molecular genetic maps and marker-assisted selection. Followed by RAPD (1990), SSR/microsatellites (mid-1990s), and SNPs (2000s).
• Larkin & Scowcroft (1981): Coined the term 'somaclonal variation' — heritable variation among plants regenerated from tissue culture. Opened a new avenue for generating useful variation without hybridization.
• John Sanford (1987): Invented the gene gun (biolistic method) at Cornell University — gold/tungsten particles coated with DNA fired into plant cells. Enabled transformation of monocots (maize, wheat) that are difficult to transform with Agrobacterium.
• Bt cotton commercialized (1996 USA, 2002 India): Cry1Ac gene from Bacillus thuringiensis expressed in cotton for bollworm resistance. India's first and (as of 2025) only commercialised GM crop. Within a decade, Bt cotton covered >95% of India's cotton area (verify current figure from Cotton Corporation of India data).
• Arabidopsis genome (2000), Rice genome (2002): First plant genome sequences. Rice genome (Oryza sativa) — an international public effort — enabled identification of all genes. Wheat genome completed in 2018 — 14 times larger than human genome, highly complex due to hexaploidy.
• CRISPR-Cas9 (2012): Jennifer Doudna and Emmanuelle Charpentier published the mechanism of CRISPR-Cas9 as a programmable genome editing tool. Awarded Nobel Prize in Chemistry 2020. The most transformative tool in plant breeding since rDNA technology. Enables precise gene editing without introducing foreign DNA (SDN-1, SDN-2 edits).
• Speed Breeding (Watson et al., 2018): Extended photoperiod (22 hours) + optimal temperature enables 4–6 generations/year in cereals. Combined with genomic selection and DH technology, enables ultra-rapid variety development. ICAR adopted speed breeding protocols around 2021 (please verify exact year from ICAR annual reports).

IMPORTANCE OF GENETIC ENGINEERING PHASE (IFoS 2025 Asked Specifically)

Why the Genetic Engineering Phase is Revolutionary:

• TRANSCENDS SEXUAL BARRIERS: Conventional breeding is limited to sexually compatible species. Genetic engineering enables transfer of genes from bacteria (Bt toxin from Bacillus thuringiensis), viruses, or any organism into crops.
• PRECISION: Unlike mutation breeding (random changes), genetic engineering introduces specific, characterised genes at defined locations. CRISPR-Cas9 further improved precision by editing existing genes without random insertion.
• SPEED: Transgenic variety development can take 7–10 years from gene identification to commercial release, but this compares favourably to the 15–20 years sometimes needed for wide hybridisation-based introgression of alien genes.
• MULTI-TRAIT ENGINEERING: Multiple genes (gene stacking) can be introduced simultaneously, unlike conventional backcrossing that transfers one trait at a time.
• NUTRITIONAL ENGINEERING: Golden Rice (beta-carotene), High-lysine maize, Iron-biofortified crops — traits impossible or extremely difficult to achieve through conventional crossing.
• HERBICIDE AND PEST TOLERANCE: Roundup Ready soybean, Bt cotton/brinjal/maize reduced pesticide use dramatically in countries where commercialised.
• GENOME EDITING (CRISPR): Now enables changes indistinguishable from natural mutation (SDN-1 edits). India's DBT exempted SDN-1 and SDN-2 CRISPR edits from GM regulations in May 2022 — a landmark policy change.

1.4 Eminent Scientists and Their Contributions

This is a high-frequency question area — both in IFoS and CSE. You should know at least 8–10 international and 6–8 Indian scientists with their specific contributions. The following comprehensive table is compiled from all source materials.

A. International Scientists

B. Indian Plant Breeders 

UPSC CSE specifically asks about Indian scientists. You need to know each person's institution, crop, specific varieties developed, and their broader impact.

M.S. Swaminathan (1925–2023) — Father of Indian Green Revolution

• Institution and Background:
  • Geneticist; trained at IARI, University of Wisconsin, and Cambridge.
  • Director of IARI (1966–1972);
  • Director General ICAR (1972–1979);
  • Principal Secretary Ministry of Agriculture;
  • Director General IRRI (1982–1988).

Specific Contributions:

• Introduced Mexican semi-dwarf wheat varieties Sonora 64 and Lerma Rojo into India in collaboration with Norman Borlaug (1965–66). This triggered the Green Revolution and raised wheat production from approximately 12 million tonnes (1965) to 17 million tonnes (1968) — please verify these figures from ICAR/Ministry of Agriculture publications.
• Developed Sharbati Sonora — an amber-grained wheat through mutation breeding on Sonora 64 using gamma rays. Became the first premium-quality Indian wheat variety.
• Established MSSRF (M.S. Swaminathan Research Foundation) in 1988 in Chennai — pioneered sustainable agriculture, biofortification, and participatory plant breeding.
• Chaired the National Commission on Farmers (2004–2006) — recommended MSP should be at least 50% above C2 cost of production.
• First World Food Prize laureate (1987); Padma Vibhushan (1989); Bharat Ratna awarded posthumously in 2024 (please verify from official Bharat Ratna announcements).

B.P. Pal (1906–1989) — Pioneer of Indian Wheat Breeding

• First Indian Director of IARI (1950–1965); first Director-General of ICAR (1965).
• Developed NP (New Pusa) series of wheats (NP 4, NP 52, NP 165, NP 700, NP 809, NP 832) through pure line selection — the backbone of pre-Green Revolution Indian wheat breeding.
• These varieties showed excellent rust resistance and grain quality.
• Founded the Cytogenetics and Plant Breeding division at IARI.
• Trained generations of Indian plant breeders.

History of Plant Breeding in India — Timeline

Landmark Achievements of Plant Breeding 

This section consolidates the specific varietal milestones most frequently tested in UPSC answers.

EXAM ANGLE

TOP EXAM TIPS FOR CHAPTER 1: 

• Always start with definition (Simmonds 1979 or GPBR 211 definition).
• Give all 5 phases in sequence with at least 2–3 scientists per phase.
• IFoS 2025 specifically wanted genetic engineering phase in detail — CRISPR, Bt cotton, GM mustard, CRISPR regulation in India.
• CSE consistently asks about Green Revolution (Borlaug + Swaminathan), and specific Indian varieties. 
•  The scientists table above has been tested directly in IFoS questions like 'Name the scientist who...' type questions.
• Mention undesirable effects of plant breeding when asked broadly about 'scope' or 'role' of plant breeding — it shows balanced thinking.