All biotic components are made up of genetic materials. These are naturally preserved for continuity. Recent developments indicate that their availability may not always be consistently guaranteed. Germplasm is living tissue from which new plants can be grown.
It can be a seed or another plant part – a leaf, a piece of stem, pollen, or even just a few cells that can be turned into a whole plant.
Germplasm contains the information for a species’ genetic makeup and serves as a valuable natural resource for plant diversity. Biotechnology cannot thrive without these resources. This article identifies the safe methods and places for germplasm preservation.
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Definition and Agricultural Importance of Germplasm
Germplasm is living tissue from which new plants can be grown. It can be a seed or another plant part – a leaf, a piece of stem, pollen, or even just a few cells that can be turned into a whole plant.
Germplasm contains the information for a species’ genetic makeup and is a valuable natural resource of plant diversity.
Agriculture benefits from uniformity among crop plants within a variety, which ensures consistent yields and easier management. However, genetic uniformity makes crops more vulnerable to new pests and stresses.
The genetic diversity of germplasm provides plant breeders with the sustained ability to develop new high-yielding and high-quality varieties that can resist evolving pests, diseases, and environmental challenges.
Sexually compatible wild species and landraces ancestral varieties of crop species are essential to this genetic diversity. Unfortunately, the land where these plants grow wild is shrinking, and many species and varieties are disappearing.
This has prompted the plant science community to develop conservation programs to gather, preserve, evaluate, catalogue, and distribute germplasm for global agricultural use.
Reasons for Germplasm Collection in Agriculture
The main reasons for collecting germplasm of a specific gene pool in a given area include the following:
1. It is in danger of genetic erosion or extinction Germplasm may be disappearing due to habitat loss or climate change.
2. There is a clear need for it expressed by users nationally or internationally Certain crop traits may be in demand for breeding programs.
3. The diversity it represents is missing or underrepresented in existing ex situ germplasm collections Gaps in collections can hinder breeding progress.
4. More information is needed about it – Research gaps can delay the development of improved varieties.
These reasons are not mutually exclusive. Germplasm may be both threatened and useful, with existing knowledge and collection gaps.
While collecting is essential, it is only one aspect of a broader conservation strategy, which may include in situ conservation. A successful collection programme does not eliminate the need for continued efforts to conserve the target gene pool.
Characterisation of Germplasm for Agricultural Use
Germplasm characterisation involves recording distinctly identifiable and heritable traits. This differs from preliminary evaluation, which focuses on a limited number of agronomic traits important in crop improvement.
Characterisation is conducted in precision fields under proper agronomic and plant protection conditions. For each accession, several morpho-agronomic traits are recorded using standard descriptors developed in collaboration with Bioversity International (formerly IPGRI).
At ICRISAT gene bank, most of the germplasm collection has been characterised using this approach. Systematic description of each accession leads to classification into smaller, well-organised sectors, making germplasm utilisation more effective.
The major objectives of germplasm characterisation include:
1.To describe accessions, establish diagnostic traits, and identify duplicates*
2.To classify accessions into well-defined groups using valid criteria*
3.To identify accessions with desirable agronomic traits for further evaluation*
4.To develop interrelationships among traits and geographic groups*
5.To estimate the extent of variation within the collection*
Achieving these objectives requires a multi-disciplinary approach. At ICRISAT, data from various disciplines are integrated into the germplasm database. As a result of detailed field and laboratory assessments, a wide range of sources for desirable traits have been identified within the assembled germplasm.
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Germplasm Storage Centres in Agricultural Research
Genebanks have been established in several countries, with over six million accessions conserved across approximately 1,400 genebanks (FAO 1998).
The mission of the Consultative Group on International Agricultural Research (CGIAR) is to achieve sustainable food security and reduce poverty through agricultural research and development. Among its objectives are the exploration, exchange, and conservation of plant genetic resources.
ICRISAT, one of the 15 CGIAR centers, has established a Genetic Resources Unit focused on the assembly, characterisation, evaluation, maintenance, conservation, documentation, and distribution of germplasm. Target crops include:
- Sorghum (Sorghum bicolor (L.) Moench.)
- Pearl millet (Pennisetum glaucum (L.) R. Br.)
- Chickpea (Cicer arietinum L.)
- Pigeonpea (Cajanus cajan (L.) Millsp.)
- Groundnut (Arachis hypogaea L.)
- Finger millet (Eleusine coracana (L.) Gaertn.)
- Foxtail millet (Setaria italica (L.) P. Beauv.)
- Barnyard millet (Echinochloa crus-galli (L.) P. Beauv.)
- Kodo millet (Paspalum scrobiculatum L.)
- Little millet (Panicum sumatrense Roth ex Roem. & Schult.)
- Proso millet (Panicum miliaceum L.)
Methods of Germplasm Preservation in Agriculture
In summary, germplasm can be preserved in standardised facilities and environments such as:
- Seed banks
- Crop-type collection centers or field gene banks
- Natural ecosystems
- Collection missions
- Cryopreservation centers
Seeds are the most convenient plant parts for storage, although a few species exhibit recalcitrant behavior, such as Telfairia occidentalis.
Under proper temperature and humidity conditions, seeds can be stored for many years. Therefore, after collection, reliable seed banks must be established to conserve the samples. Regular viability tests are essential to ensure seed quality over time. A well-managed seed bank serves as crucial insurance against the permanent loss of any collected species.
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Frequently Asked Questions
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