About the National Tree Seed Centre

Questions and Answers

• What is the National Tree Seed Centre?
• Why collect and store seed?
• Who wants this seed?
• How is seed collected and stored?
• How long can the seed be stored and will it grow after freezing?

What is the National Tree Seed Centre (NTSC)?

• A collection, processing, testing, and storage facility for tree and shrub seed.
• The long-term goal is to store representative samples from throughout the natural ranges of all Canadian tree and shrub species.
• The Centre provides seed of known origin and quality for research purposes to researchers around the world.
• An active participant in genetic conservation of tree and shrub species native to Canada.
• Research and development of processing and germination testing methods and procedures.
• The Centre has seed from about 100 Canadian tree and shrub species as well as over 100 exotic species for a total of over 11000 individual seed lots.
  
  Why collect and store seed?

• Scientists have an ongoing need for seed for a number of diverse projects such as species introductions, provenance trials, isozyme studies, germination tests, molecular investigations, and tissue culture.
• The NTSC only collects from natural populations. The Centre's collection will become increasingly valuable for genetic conservation of commercial tree species because seed for reforestation is being supplied from seed orchards.
• It is important to collect and store seed from natural populations that may be unique, endangered or threatened.

Who wants this seed?

• Researchers at Canadian universities and provincial and federal governments as well as agencies in other countries throughout the world.
• Scientists concerned with long-term conservation and restoration strategies.
• The majority of seed requests are for native Canadian species.

How is seed collected and stored?

• Most of the seed is collected by Seed Centre staff. However, with cooperation from other Canadian Forest Service centres, provincial forest services, forest industries, and other agencies, more seed is obtained.
• Seed is collected from natural populations.
• A varity of methods are used to collect seed such as a bucket truck, climbing, pole pruners, directly from the tree, or from the ground.
• Seed is collected in "good" seed years to ensure high genetic and physiological quality and from individual trees or a number of trees in order to have a representative genetic sample of the population.
• Seed is processed, cleaned, tested for moisture, 1000-seed weight determined, and stored in glass jars.
  
  
• Germination tests are conducted before seed is stored to assess seed quality. These tests are also carried out on stored seed to monitor changes in viability over time.
  
  
• Practically all the seed is stored at -20°C. At this temperature it can be kept for many decades provided the moisture content of the seed is low (5-8%). Some hardwood species, such as oak and silver maple do not store well. These seeds are stored at 4°C and collections are made frequently to maintain a viable supply.
• Seed is also stored in liquid nitrogen at -196° C. This technique is called cryopreservation. Due to the expense of operating this system only seed from special collections or unique populations is stored.
  

How long can the seed be stored and will it grow after freezing?

• Properly stored seed can remain viable for decades.
• Seed from white spruce, black spruce, jack pine, and red pine has germinated between 65% and 85% after more than 40 years in frozen storage.
• Seed cryopreserved in liquid nitrogen may have the potential to retain viability for several hundred years.
• It is important to know that seed will live for a long time, especially when it is collected from unique populations or stands that are threatened, so it can be conserved for the future.