Applied Botany: Plant Breeding, Biotechnology and Economic Uses

9 min read

Applied botany harnesses plant science for practical human use — food, medicine, fibre, fuel, environmental services. It overlaps with genetics, agronomy, biotechnology and pharmacognosy.

Plant breeding

The art and science of changing the traits of plants to produce desired characteristics. Modern plant breeding combines classical selection with molecular markers and biotechnology to develop improved cultivars for yield, quality, stress tolerance and resistance.

Plant breeding methods

1. Selection

Mass selection — choosing superior plants from a heterogeneous population.
Pure-line selection — repeated selfing produces homozygous lines.
Pedigree selection — track lineage in segregating populations.

2. Hybridisation

Intra-specific — within a species.
Inter-specific — between species (e.g. Triticum × Secale = triticale).
Heterosis (hybrid vigour) is exploited in F1 maize and sunflower hybrids.

3. Mutation breeding

Use of physical (X-rays, gamma) or chemical mutagens (EMS) to induce variation.
IAEA-supported programmes have released hundreds of mutant crop varieties globally.
In Pakistan, NIAB Faisalabad released cotton variety NIAB-78 in 1983 and many others.

4. Polyploid breeding

Doubling chromosomes with colchicine.
Triticale (hexaploid) is a polyploid wheat-rye hybrid.

5. Marker-Assisted Selection (MAS)

DNA markers tag genes of interest; speeds up breeding.

6. Genetic engineering / transgenics

Direct insertion of foreign DNA — Bt cotton, Bt brinjal, Golden Rice (vitamin A enriched).

Plant tissue culture

In vitro growth of plant cells, tissues or organs under sterile conditions on defined nutrient media. Murashige & Skoog (MS medium, 1962) is the workhorse formula.

Applications:

Micropropagation — rapid clonal multiplication (banana, potato seed certification).
Embryo rescue for wide hybrids.
Anther culture for haploid production.
Somatic embryogenesis.
Production of secondary metabolites (taxol, shikonin).
Cryopreservation of germplasm.

Transgenic crops in Pakistan

Bt cotton — first approved varieties in 2010 (NIBGE-deployed event MON 531).
Subsequent debates around stacked events, IPR, and pink-bollworm resistance.
Other crops being researched: Bt brinjal, herbicide-tolerant maize, drought-tolerant wheat.
Regulated under the Pakistan Biosafety Rules 2005 and National Biosafety Centre.

Key Points

Norman Borlaug (1914–2009) — "Father of Green Revolution"; Nobel Peace Prize 1970; bred semi-dwarf wheats at CIMMYT.
MS medium (1962) is the standard plant tissue-culture medium.
Bt cotton carries genes from Bacillus thuringiensis against bollworm.
NIBGE Faisalabad and NIAB Faisalabad are PAEC's biotechnology centres.
The National Biosafety Centre under MoCC regulates GMOs.

Economic botany — important plant products

Food plants

Cereals: wheat, rice, maize, barley, sorghum, millets.
Pulses: gram, lentil, mung, mash.
Oilseeds: rapeseed, sunflower, soybean, sesame.
Sugar: sugarcane, sugar beet.

Fibre plants

Cotton — Gossypium hirsutum — vital to Pakistan's textile economy.
Jute (Corchorus), flax (linen), hemp, sisal, kapok.

Beverage plants

Tea (Camellia sinensis) — grown experimentally in Shinkiari, KP.
Coffee (Coffea arabica, C. canephora).
Cocoa (Theobroma cacao).

Spices and condiments

Black pepper, cardamom, cinnamon, clove, turmeric, cumin, coriander, fenugreek.

Timber

Deodar, shisham, sal, teak, walnut, kail.

Medicinal plants

Pakistan has rich ethnobotanical heritage. Key examples:

Plant	Active compound	Use
Withania somnifera (ashwagandha)	Withanolides	Adaptogen
Berberis lycium (kashmal)	Berberine	Antimicrobial
Taxus wallichiana	Paclitaxel (Taxol)	Anti-cancer
Artemisia annua	Artemisinin	Anti-malarial
Catharanthus roseus (sadabahar)	Vincristine, vinblastine	Anti-cancer
Cinchona	Quinine	Anti-malarial
Papaver somniferum	Morphine, codeine	Analgesic
Digitalis	Digitoxin	Cardiotonic

Energy plants

Bioethanol — sugarcane, maize, sweet sorghum.
Biodiesel — Jatropha, Pongamia, oil palm.

Plant disease and pests

Fungal: rusts (wheat), smuts, mildews, Fusarium wilt of cotton.
Bacterial: bacterial blight of rice, citrus canker.
Viral: Cotton Leaf Curl Virus (CLCuV) — Pakistan's most damaging cotton disease since 1992.
Pests: bollworms, locust (2019–20 outbreak), aphids, whitefly.

Integrated Pest Management (IPM) combines cultural, biological, mechanical and chemical control.

Phytoremediation

Use of plants to remove or stabilise pollutants — heavy metals, hydrocarbons, salts. Examples: Pteris vittata for arsenic, Brassica juncea for lead, Vetiveria zizanioides for erosion and contamination.

For applied botany essays, marry classical breeding (Borlaug, semi-dwarf wheat, Mexipak) with modern biotechnology (Bt cotton, NIBGE, regulated by Pakistan Biosafety Rules 2005). Mention paclitaxel from Taxus wallichiana and artemisinin from Artemisia annua as showcase plant-derived drugs; both Nobel-linked discoveries reward citation.

Conservation of plant genetic resources

CGIAR centres — CIMMYT (wheat/maize), IRRI (rice), ICARDA (drylands), CIP (potato).
Plant Genetic Resources Institute (PGRI) at NARC, Islamabad — Pakistan's national gene bank.
Svalbard Global Seed Vault (2008) — backup of accessions worldwide.

ICN-listed biotechnology controversies

Terminator (GURT) technology — seeds that produce sterile offspring.
Glyphosate-resistant crops — herbicide-resistance concerns.
Patenting of indigenous knowledge (basmati case, neem case).

Quotation: "Without plant breeders, humanity would be hungry, naked and cold." — Norman Borlaug.