Discuss the importance of conservation of plant genetic resources for crop improvements.

What are Plant Genetic Resources?

Plant Genetic Resources (PGR) refer to the heritable material of plants that can be used for breeding purposes. They include seeds, pollen, vegetative propagating material, and in vitro cultures. PGR can be found in various forms: wild relatives of crops, landraces (locally adapted traditional varieties), and modern cultivars. The Convention on Biological Diversity (CBD) recognizes PGR as a vital component of biodiversity.

Importance of Conservation of Plant Genetic Resources

The conservation of PGR is vital for several reasons, spanning food security, climate change adaptation, and sustainable agriculture.

• Source of Novel Genes: Wild relatives and landraces often possess genes for traits absent in modern cultivars, such as disease resistance, drought tolerance, and improved nutritional content.
• Climate Change Adaptation: As climate change intensifies, PGR offer a crucial resource for breeding crops that can withstand extreme weather events like droughts, floods, and heat waves.
• Disease and Pest Resistance: Emerging diseases and pests threaten crop yields. PGR provide genes that can be incorporated into crops to confer resistance. The recent wheat blast disease outbreak highlights the need for resistant varieties.
• Nutritional Security: Landraces often have higher levels of micronutrients compared to modern varieties, contributing to improved nutritional security. Biofortification efforts rely heavily on PGR.
• Maintaining Crop Diversity: Conserving PGR helps maintain the genetic diversity within crop species, reducing the vulnerability of agriculture to unforeseen challenges.

Methods of Conservation

PGR conservation employs two primary strategies: ex situ and in situ conservation.

Ex Situ Conservation

This involves collecting and storing germplasm outside its natural habitat. It includes:

• Seed Banks: These are gene banks where seeds are stored under controlled conditions (low temperature and humidity) to maintain viability. The Svalbard Global Seed Vault in Norway is a prominent example.
• Field Gene Banks: Collections of living plants are maintained in fields, often used for species that do not regenerate well from seed.
• In Vitro Conservation: Using techniques like cryopreservation to preserve plant tissues and cells.
• National Botanical Research Institute (NBRI), Lucknow maintains a large collection of plant genetic resources.

In Situ Conservation

This involves conserving PGR within their natural ecosystems.

• Protected Areas: Establishing national parks and wildlife sanctuaries to safeguard wild relatives of crops.
• On-Farm Conservation: Supporting farmers in maintaining traditional varieties and landraces. The "Namma Bhoomi" initiative in Karnataka, India, promotes on-farm conservation by documenting and preserving traditional seed varieties.

Contribution to Crop Improvement

Conserved PGR serve as a vital resource for crop improvement through various methods:

• Traditional Breeding: Wild relatives can be crossed with cultivated varieties to introduce desirable traits. The development of disease-resistant wheat varieties by incorporating genes from wild wheat species is a classic example.
• Genetic Engineering: Genes from PGR can be identified and cloned for insertion into crop plants using genetic engineering techniques. Bt cotton, which contains a gene from Bacillus thuringiensis, is a prime example of this.
• Marker-Assisted Selection (MAS): Molecular markers linked to desirable genes in PGR can be used to accelerate the breeding process.
• Genome Editing: Newer techniques like CRISPR-Cas9 allow for precise gene editing, enabling targeted improvement of crop traits using PGR genes.

Challenges and Institutions

Despite the importance of PGR conservation, several challenges exist:

• Limited Funding: Conservation efforts often face funding constraints.
• Lack of Awareness: There is a need to raise awareness among farmers and policymakers about the importance of PGR.
• Biopiracy: The illegal appropriation of PGR by foreign entities is a concern. India’s Protection of Plant Varieties and Farmers’ Rights Act, 2001, aims to prevent biopiracy.
• Climate Change Impacts: Changing climate conditions threaten the survival of both ex situ and in situ collections.

Key institutions involved in PGR conservation include:

• Food and Agriculture Organization (FAO): Promotes PGR conservation globally.
• Consultative Group on International Agricultural Research (CGIAR): Supports research and conservation efforts.
• National Bureau of Plant Genetic Resources (NBPGR), India: India’s premier PGR conservation institute.

Conservation Type	Description
Ex Situ	Collection and storage of germplasm outside its natural habitat (e.g., seed banks, field gene banks).
In Situ	Conservation within natural ecosystems (e.g., protected areas, on-farm conservation).

The conservation of plant genetic resources is not merely an environmental imperative but a fundamental requirement for ensuring global food security and resilience. The diverse genetic material held within these resources offers a crucial buffer against climate change, emerging diseases, and nutritional deficiencies. Continued investment in both ex situ and in situ conservation, coupled with the responsible application of modern breeding technologies, is essential to safeguarding our agricultural future. A collaborative approach involving governments, research institutions, and farmers is vital for preserving this invaluable heritage for generations to come.