Strategies for Germplasm Conservation: Ensuring Biodiversity for Future Generations

Every crop variety we grow today exists because someone, somewhere, preserved its genetic material. Germplasm – the living genetic resources found in seeds, tissues, pollen, and other plant parts – forms the backbone of agricultural development. Without conserving it, we risk losing the very building blocks that plant breeders need to develop climate-resilient, high-yielding, and disease-resistant crop varieties. Germplasm conservation is the systematic effort to protect this genetic wealth using a range of strategies, from safeguarding plants in their natural habitats to storing seeds in high-tech vaults at sub-zero temperatures.

What is germplasm and why does it matter? 🔗

Germplasm refers to the total genetic content of an organism that can be passed on to the next generation. In agriculture, it specifically means the genetic material of cultivated crops, their wild relatives, landraces, and breeding lines that researchers and breeders use for crop improvement. This includes seeds, plant tissues, pollen, and even DNA samples.

The importance of germplasm is hard to overstate. Plant breeders rely on diverse genetic material to develop varieties that can withstand new pest outbreaks, adapt to changing climatic conditions, and meet evolving nutritional demands. When genetic diversity is lost – through habitat destruction, replacement of traditional varieties with modern cultivars, or environmental degradation – it is gone permanently. It is estimated that over 100,000 plant species, more than one-third of all the world’s plant species, are currently threatened or facing extinction in the wild.

This is exactly why germplasm conservation is critical. It ensures that genetic diversity remains available for current and future crop improvement programmes, helping agriculture stay resilient in the face of climate change and food security challenges.

In situ conservation: protecting plants in their natural habitats 🔗

In situ conservation means preserving plant genetic resources in the environments where they naturally occur. This includes both wild species in their native ecosystems and traditional crop varieties (landraces) managed by farmers in their fields. The core idea is simple: let plants continue evolving in response to natural environmental pressures so that they develop new genetic adaptations over time.

How in situ conservation works 🔗

In situ conservation is carried out through the establishment and management of protected areas such as national parks, wildlife sanctuaries, and biosphere reserves. Within these designated zones, plant populations are maintained in their original habitat, allowing natural selection, gene flow, and adaptation to continue. Unlike stored seeds in a freezer, in situ populations are dynamic – they keep generating new genetic variation as they respond to changing environmental conditions, pests, and diseases.

Another key form of in situ conservation is on-farm conservation, where farmers continue to cultivate traditional varieties and landraces alongside modern cultivars. Farmer seed management practices – selecting seeds, exchanging varieties with neighbours, adapting cultivation to local conditions – play a major role in maintaining crop genetic diversity at the community level. This form of conservation is especially important in developing countries where farmers have been stewards of crop diversity for thousands of years.

Advantages and limitations 🔗

The biggest advantage of in situ conservation is that it allows continued evolution. Plants exposed to changing selective pressures are more likely to develop useful new traits, including resistance to emerging diseases or tolerance to drought. It also conserves the entire ecosystem, not just the target species, which means associated organisms like pollinators and soil microbes are maintained as well.

However, in situ conservation has limitations. Natural habitats face threats from deforestation, urbanization, climate change, and invasive species. Small, isolated populations are vulnerable to genetic drift and inbreeding. There is also no guarantee about the long-term persistence of the conserved genetic material – a single disaster can wipe out an entire population. For these reasons, in situ conservation works best when complemented by ex situ methods.

Ex situ conservation: safeguarding germplasm outside natural habitats 🔗

Ex situ conservation involves collecting genetic material from its natural environment and storing it in specialised facilities. This is the most widely practised method of germplasm conservation globally. According to the Food and Agriculture Organization (FAO), about 7.4 million germplasm accessions of different crop species have been collected and maintained in over 1,750 ex situ gene banks around the world.

Ex situ conservation takes several forms, each suited to different types of plant material and conservation goals.

Seed gene banks 🔗

Seed banks are the most common and cost-effective method of ex situ conservation. Seeds are dried to low moisture content (around 3-7%) and stored at sub-zero temperatures, typically at −18°C to −20°C for long-term (base) collections. Under these conditions, seeds of orthodox species (those tolerant of desiccation) can remain viable for 50 years or more without significant loss of germination ability.

Seed banks maintain two types of collections. Active collections are stored at around 4°C and used for ongoing research, distribution, and evaluation. Base collections are held at colder temperatures for long-term preservation and are monitored periodically – usually every 10 years – to check that seed viability remains above the required threshold.

The main advantage of seed banks is that they can conserve a large number of genetically diverse samples in relatively small spaces, under pathogen-free and insect-free conditions. However, this method does not work for species with recalcitrant seeds – those that cannot tolerate drying or cold storage, such as mango, litchi, jackfruit, and cocoa.

Field gene banks 🔗

For species that produce recalcitrant seeds or do not readily produce seeds at all, field gene banks offer an alternative. These are living collections of plants maintained outdoors or in greenhouses. Field gene banks are commonly used for vegetatively propagated crops like sugarcane, banana, cassava, and various fruit trees. While they provide a practical solution for conserving such species, they require more space, are more expensive to maintain, and are vulnerable to weather events, pests, and diseases.

Botanical gardens 🔗

Botanical gardens have a long history of plant conservation. Globally, more than 1,700 botanical gardens and institutions hold living plant collections that serve both conservation and educational purposes. They grow and display diverse plant species, including rare and threatened ones, and often participate in seed collection, research, and public awareness programmes. While botanical gardens are not primarily designed for large-scale germplasm storage, they contribute significantly to maintaining plant diversity and generating knowledge about species biology.

Tissue culture and in vitro conservation 🔗

In vitro conservation uses tissue culture techniques to maintain plant material – such as shoot tips, meristems, and cell cultures – under controlled laboratory conditions. Growth-limiting conditions (low temperatures, reduced nutrients, or growth regulators) are used to slow down plant growth and extend the storage period. This method is particularly valuable for vegetatively propagated crops and species with recalcitrant seeds that cannot be dried and frozen.

India’s ICAR-National Bureau of Plant Genetic Resources (NBPGR) maintains an in vitro gene bank with over 40,000 cultures representing 53 genera and 138 species. This facility stores material from crops like mango, banana, citrus, and black pepper that would otherwise be difficult to conserve through conventional seed banking.

Cryopreservation 🔗

Cryopreservation is the storage of plant material at ultra-low temperatures, typically in liquid nitrogen at −196°C. At this temperature, all metabolic activity stops completely, allowing indefinite storage without genetic deterioration. Different types of plant material – seeds, shoot tips, embryos, pollen, and cell suspensions – can be cryopreserved.

This technique is considered one of the most promising approaches for long-term conservation of plant genetic resources, especially for species that cannot be stored using conventional seed banking. The main challenge is developing reliable protocols for freezing and thawing different plant tissues without damaging them – and verifying that the recovered plants are genetically identical to the original material.

DNA banks and pollen banks 🔗

DNA banks store extracted genomic DNA from plant species as a molecular reference. While DNA alone cannot regenerate a whole plant, it preserves the complete genetic information for research, molecular studies, and future biotechnological applications. Pollen banks serve a different purpose – they preserve pollen for use in breeding programmes, especially for species that do not produce orthodox seeds. Pollen can be stored in limited space and used for cross-pollination to introduce desired traits into new varieties.

Global landmarks in germplasm conservation 🔗

The Svalbard Global Seed Vault 🔗

Located deep inside a mountain on the Norwegian island of Spitsbergen in the Arctic, the Svalbard Global Seed Vault is the world’s largest backup facility for crop diversity. Opened in 2008, it serves as a safety net for the global network of gene banks by storing duplicate samples of their seed collections.

The vault stores seeds at −18°C in sealed three-ply foil packages, with the surrounding permafrost providing a natural fail-safe cooling system. As of June 2025, the facility holds over 1.35 million accessions from over 120 depositing institutions across nearly 90 countries. It has the capacity to store up to 4.5 million crop varieties.

The vault’s practical value was demonstrated during the Syrian civil war when the International Center for Agricultural Research in the Dry Areas (ICARDA) could no longer maintain its gene bank in Syria. ICARDA withdrew backup samples from Svalbard, regenerated them in Lebanon and Morocco, and eventually returned seeds to the vault – the only withdrawals in its history.

India’s National Gene Bank 🔗

India, as one of the world’s most biodiversity-rich countries with over 811 cultivated crop species and 902 crop wild relatives, has developed a robust germplasm conservation infrastructure. The National Gene Bank (NGB) at ICAR-NBPGR in New Delhi was established in 1996 and is the second-largest gene bank globally. It currently conserves over 4.7 lakh (470,000) accessions from 2,157 species.

The NGB operates four types of conservation facilities: a seed gene bank at −18°C, a cryo gene bank at −170°C to −196°C, an in vitro gene bank at 25°C, and field gene banks across its 10 regional stations. In the Union Budget 2025-26, the Indian government announced the establishment of a second National Gene Bank with the capacity to conserve 10 lakh (1 million) germplasm lines, further strengthening India’s position in global biodiversity conservation.

In situ vs. ex situ: complementary, not competing 🔗

A common misconception is that in situ and ex situ conservation are alternative strategies – that one must choose between them. In reality, they are complementary approaches, and effective germplasm conservation programmes use both.

Ex situ collections are sometimes described as “frozen snapshots” – they capture genetic variation at a single point in time. Once seeds are stored, they no longer evolve or generate new genetic combinations. In situ conservation fills this gap by allowing populations to keep adapting to changing environments, potentially producing novel alleles that could be invaluable for future breeding programmes.

On the other hand, in situ populations are vulnerable to sudden destruction. A wildfire, flood, or land-use change can eliminate decades of genetic diversity overnight. Ex situ collections provide a safety net against such losses. The most robust conservation strategies, therefore, integrate both approaches – maintaining living populations in the field while storing backup samples in gene banks.

Challenges in germplasm conservation 🔗

Despite the advances in conservation technology, several challenges persist. Funding constraints remain a major issue, as maintaining gene banks and protected areas requires sustained long-term investment. Many gene banks in developing countries face equipment failures, power outages, and inadequate infrastructure.

Genetic erosion continues at an alarming rate. As modern high-yielding varieties replace traditional landraces in farmers’ fields, locally adapted genetic diversity disappears. Climate change compounds the problem by altering habitats faster than conservation strategies can adapt.

There are also technical limitations. Recalcitrant seed species, vegetatively propagated crops, and species with complex reproductive biology remain difficult to conserve reliably. Developing standardized cryopreservation protocols for diverse species is an ongoing research challenge. Additionally, conserved germplasm is only useful if it is properly characterised, documented, and made accessible to breeders – something that many gene banks still struggle with due to limited resources.

Finally, policy and governance issues around access and benefit-sharing can complicate international germplasm exchange. The International Treaty on Plant Genetic Resources for Food and Agriculture (ITPGRFA), adopted in 2001, provides a multilateral framework for sharing plant genetic resources, but implementation remains uneven across countries.

The road ahead 🔗

Advances in biotechnology are opening new avenues for germplasm conservation. Genomic tools now allow researchers to characterise stored collections at the molecular level, identifying useful genes and alleles more efficiently than ever before. Digital databases and bioinformatics platforms are making it easier to document, manage, and share information about germplasm collections worldwide.

Community-based conservation is gaining recognition as a vital complement to institutional efforts. Farmer-managed seed systems, participatory plant breeding, and traditional knowledge about local crop varieties all contribute to maintaining genetic diversity at the grassroots level. Integrating these efforts with formal gene bank systems can create a more resilient and inclusive conservation framework.

The goal is clear: build a comprehensive, well-connected global system where in situ and ex situ strategies work together, supported by modern technology and inclusive policies, to ensure that the genetic diversity agriculture depends on is never lost.

What do you think? With climate change accelerating and traditional crop varieties disappearing from farmers’ fields, are we doing enough to conserve germplasm for future food security? How can local farming communities play a bigger role in preserving the genetic diversity that modern agriculture increasingly needs?

References

1. https://plantbiotechnologylab.ualg.pt/index.php/en/research/24-germplasm-conservation
2. https://pmc.ncbi.nlm.nih.gov/articles/PMC5680627/
3. https://www.sciencedirect.com/topics/agricultural-and-biological-sciences/in-situ-conservation
4. https://www.sciencedirect.com/topics/agricultural-and-biological-sciences/germplasm-conservation
5. https://www.sciencedirect.com/topics/agricultural-and-biological-sciences/ex-situ-conservation
6. https://nbpgr.org.in/nbpgr2023/germplasm-conservation-division-new-delhi/
7. https://www.croptrust.org/what-we-do/programs/svalbard-global-seed-vault/
8. https://en.wikipedia.org/wiki/Svalbard_Global_Seed_Vault
9. https://pmc.ncbi.nlm.nih.gov/articles/PMC7907825/
10. https://www.pib.gov.in/PressReleasePage.aspx?PRID=2116216