Molecular breeding (Marker-Assisted Selection)

Definition: The use of DNA markers linked with desirable traits to aid in selection during breeding.

Steps:

1. Identification of markers linked to target gene
2. Marker validation
3. Screening of progenies
4. Selection based on marker presence

Advantages:

• Faster and more accurate than traditional breeding
• Useful for polygenic traits (e.g., drought tolerance)
• Early generation selection

Examples in India:

Biotechnology in seed industry

• Production of disease-free seed stock through tissue culture.
• Hybrid seed production using male sterility systems.
• DNA fingerprinting for seed purity testing.
• Germplasm conservation using cryopreservation (–196°C in liquid nitrogen).

Industrial applications

• Enzyme production: Amylase, cellulase, protease.
• Biofuels: Ethanol from sugarcane, biodiesel from Jatropha.
• Fermentation products: Antibiotics, amino acids, organic acids.
• Bioplastics: PHB (polyhydroxybutyrate) from Ralstonia eutropha.

Biotechnology in india

Institutions involved:

• ICAR – Indian Council of Agricultural Research
• DBT – Department of Biotechnology
• NBPGR – National Bureau of Plant Genetic Resources
• NRCPB – National Research Centre on Plant Biotechnology (now NIPB)
• IARI – Indian Agricultural Research Institute

Limitations & concerns

1. Ethical issues (GM foods and biodiversity)
2. Gene escape to wild relatives
3. Development of resistance in pests (e.g., Bt resistance)
4. High cost of technology
5. Public acceptance and biosafety regulations

Important one-line facts

1. Father of Biotechnology: Karl Ereky (1919)
2. Father of Plant Tissue Culture: Gottlieb Haberlandt (1902)
3. Father of Genetic Engineering: Paul Berg
4. Father of Indian Biotechnology: Dr. Pushpa Mitra Bhargava
5. Bt gene – Derived from Bacillus thuringiensis
6. Cry1Ac – Targets Lepidopteran pests
7. Ti plasmid – Used for gene transfer in dicots
8. Ri plasmid – Causes hairy root disease
9. Golden Rice – Enriched with β-carotene (Pro-vitamin A)
10. First GM food crop developed in India: Bt Brinjal
11. Transgenic crops occupy over 190 million hectares globally (FAO, 2023).
12. India ranks 5th in area under GM crops.
13. Gene gun developed by Sanford et al. (1987).
14. PCR discovered by: Kary Mullis (1983).
15. CRISPR-Cas9 developed by Jennifer Doudna and Emmanuelle Charpentier (2012).