What is plant germplasm?
Plant germplasm is the living tissue from which new plants can be grown. Germplasm is usually seed, or it can be another plant part -- a stem, a leaf, or pollen, for example, or even just a few cells that can be cultured into a whole plant. Plant germplasm contains the genetic information for the plant’s hereditary makeup.
What is the Canadian Plant Germplasm System? Canada’s Plant Germplasm System is a network of centres and people dedicated to preserving the genetic diversity of crop plants, their wild relatives and plants present and unique in the Canadian biodiversity. The system plays a significant part of Agriculture and Agri-Food Canada’s commitment to the Canadian Biodiveristy Strategy in response to the Convention on Biological Diversity.
Agriculture and Agri-Food Canada appointed the first Plant Gene Resources officer, and established Plant Gene Resources of Canada (PGRC) in 1970. Until early 1998 it was located on the Central Experimental Farm in Ottawa, but moved to a modern facility in Saskatoon. PGRC seed genebank, as part of the Saskatoon Research Centre coordinates Canada’s germplasm system and is the main repository for seed.
In the multi-nodal system, the two central agencies, PGRC and the Canadian Clonal Genebank are still the primary contact points for germplasm entering and leaving Canada, and have responsibility for national and international contacts, distribution, rejuvenation and evaluation of germplasm not assigned to the Nodes, seed viability testing, database management and technical information.
Canadian agriculture is based on crops that originated from areas outside of Canada. For example, wheat originated in the Near East (in such countries as Iran), corn in Mexico and Guatemala, alfalfa in Turkey, and soybean in China. Crops of economic importance that are native to Canada are limited and include sunflower, strawberry, raspberry, saskatoon berry blueberry, currant, and cranberry. A large number of native forage and grass species have a significant value in parts of Canada, whether for pasture, erosion control, benefit to wildlife or other usages. The largest genera are the bluegrasses, brome grass, milk vetch and wild rye. Thus, almost all of the germplasm needed to increase the genetic diversity of Canadian agriculture come from foreign locations.
Canada’s food supply is based on intensive agriculture and this benefits from genetic uniformity of crops. But genetic uniformity increases the potential for crop vulnerability to new pests and stresses. Genetic diversity gives us the sustained ability to develop new plant cultivars than can resist these pests, diseases, and environmental stresses. Wild ancestors and relatives are the keys to genetic diversity. Unfortunately the land base where wild plants grow continues to shrink, and many plant species and variants are disappearing. Also the conservation of Canadian wild plant germplasm is important as considerable material has been identified as unique in the Canadian biodiversity and to the original inhabitants of Canada. The Canadian Plant Germplasm System exists to conserve, increase utilization and catalogue germplasm of plants that might otherwise be lost.
Benefits derived from the use of Plant Genetic Resources
Plant genetic resources have been used in Canada for more than a century and all Canadians have benefited from their use through increases in the quantity and quality of food consumed. Benefits from their use have accrued through genetic improvements which have contributed to major increases in productivity and resistance to pests, diseases and adverse growing conditions. Canadian grain yields have steadily increased over the past decades and the improved quality of our products has contributed to their prestige on world markets. Canola exemplifies Canada’s contribution to enriching the world’s crop diversity as a result of our use of germplasm acquired in other countries. In recent times, for example, wide crossing in Hordeum has the potential of increasing salt and drought tolerance; native plums have been used to improve adaptability of domesticated plums; Fragaria chiloensis is better able to withstand drought; and may species of Rubus carry useful traits, including resistance to major fungal pathogens and insect pests. Shrub roses have been developed which are hardy to zone 3 and these are being widely grown, replacing the tender hybrid tea and floribunda roses. Many grass genera are adapted to xeric conditions due to drought and/or salt tolerance while others are more adapted to more mesic situations. Researchers continue to evaluate germplasm for new crop development and for value in value-added processing.
Benefits are also derived by conserving Canada’s biodiversity of indigenous plant species. In addition to commonly occurring species, threatened, rare or endangered species are made available for study or for small habitat restoration projects. Canada conserves for the world the largest collection of rare and threatened species of native plants in the genus Lotus.
Three tools improve the use of Canada’s plant genetic resource collection: better knowledge the characteristics of germplasm accessions, making this knowledge more accessible to germplasm users, and germplasm enhancement programs which integrate new genes and traits into genetic backgrounds more easily used by plant breeders.
Expert Committee on Plant and Microbial Genetic Resources
The Expert Committee on Plant and Microbial Genetic Resources reporting to the Canadian Agriculture Research Council/Canada Committee on Crops (CARC/CCC) advises on plant genetic resource policies and activities. It draws its representation from Canadian federal and provincial government agencies, universities, industry, scientific societies, and non-government organizations. Specifically the committee discusses and advises on the activities of the national program in plant genetic resources, makes recommendations to CARC on issues relating to plant and microbial genetic resources, and participates in the formulation of national plant and microbial genetic resource policy and its relationship to international programs.
Genetic Resource Information Network - Canadian Version (GRIN-CA)
Canada uses a computerized database management system to assist in handling the massive amounts of data associated with the genetic resources. The data is divided into three basic categories, namely passport, evaluation, and stock management. Researchers can learn about specific characteristics for each accession in the collection. All Nodes interact with the database regularly, entering data, conducting searches and so on. Seed requests can also be made through the database.
What the collections contains
The seed collection includes foreign and indigenous plants, wild and weedy relatives of crop species, cultivars and inbred parental lines, elite breeding lines, and some rare and threatened species and genetic stocks. Genetic stocks include induced and natural mutations, cytological stocks of genetic oddities and variations on normal chromosomes, marker genes, polyploids, and pest-resistant stocks.
Approximately 3,000 accessions are established at the Canadian Clonal Genebank in Harrow. Approximately two thirds of the collection consists of indigenous wild relatives of Canadian fruit crops and the remaining one third are cultivars or breeding selections of Canadian origin or cultivars of interest to Canadian scientists.
Seed storage facilities at PGRC consist of long-term, medium-term and cryopreservation units. For long-term storage a large walk-in vault is available in which seed is preserved in laminated envelopes at -20C. For medium-term storage a large walk-in vault stores seed in paper envelopes at 4 C and 20% relative humidity. Seeds are evaluated for viability, dried to optimum moisture content of 6-8% and transferred to either medium- or long-term storage. Cryopreservation (a type of freezing) in or over liquid nitrogen at -196C is the most highly developed of these techniques. Depending on species, dry seeds can last from a few years to centuries.
At the Canadian Clonal Genebank the clones are either stored in the field, in screen or greenhouses. Tissue culture techniques are well advanced and used for many species, and scientists are evaluating these techniques for those species that can’t be stored by other means. Tissue culture is a cloning method -- growing a whole plant from a small plant part in an artificial medium in a controlled, disease-free environment. Tissue culture is used extensively at the potato node in Fredericton for storage and distribution of germplasm.
Germplasm evaluation and regeneration
Canada’s multi-nodal system offers a number of opportunities for Canadian germplasm conservation. The rejuvenation of the major species is done at the plant breeding locations responsible for the species, allowing the central agencies to concentrate on preservation technology, genetic diversity analysis in the collections, distribution, database development, and on rejuvenation and evaluation of species not assigned to Nodes. Characterization is done by plant breeders and specialized technicians who have the expertise in the field. This permits an accumulation of relevant information on accessions, for which there is currently insufficient information. Germplasm is evaluated for a number of desirable agronomic traits such as earliness or winter hardiness, screened for resistance to pests, diseases, and environmental stress, and for quality factors such as colour and flavour. The results are made available through the national database, GRIN-CA.
The Canadian Plant Germplasm System is devoted to the free and unrestricted exchange of germplasm with all nations and permits access to Canadian collections by any person with a valid use. Normally, this means breeders and plant researchers, but others such as medical researchers and educators are welcome.
Canada is very conscious of the fact that no country can pretend to preserve on its own all of the genetic diversity needed for all of its crop plants for all time. Our country recognizes the need to coordinate and share the work of conservation among countries. Canada strongly supports and effectively participates in international collaboration programs to this end, particularly the crop networks established with the assistance of the Biodiversity International.