No two expeditions are the same. The key to a successful seed collecting expedition is thorough preparation and a flexible itinerary – there is no substitute for experience.

Seed collecting team of NRBG in a mission

Collectors often need to travel to remote areas to reach natural vegetation in a suitable state for seed collecting. Conditions can be tough and teams are dependent on the experience of their members to safely and accurately make high quality collections. A typical expedition comprises several collectors, making an average of three seed collections per day while travelling widely across their collecting region in a 4-wheel-drive vehicle. Collecting teams use a range of tools and guides to help locate target plants which are fruiting or target plants with ripe seeds. Expeditions are carefully planned but teams will vary their itineraries depending on weather conditions and the number of target species in fruit at the time of their visit.

Finding the plants

In many instances our collecting team relies substantially on our botanist knowledge, not only of what species should be collected as a priority, but also where they might be growing and when they would be dispersing seed.  The pressed specimens collected in herbaria of the country, have a wealth of information on locality and flowering or fruiting time associated with them as well. These are valuable sources of this information. Once it is digitized and available in a database, we are able to analyze this specimen information and compile it. One outcome of this process is that we produce collection guides for plant species and regions of priority for conservation. 

A collector must be certain that they have correctly identified the target species and take some time to assess the population for its potential to yield a good quality collection.

Identifying seeds

Before collecting seed, the target plant needs to be accurately identified. To do this, collectors use any field guides and checklists that may be available for the region, and carefully note any distinguishing features, such as shape and colour of flower parts, as part of the comprehensive data recorded in the field.

To be certain that the correct name is used for the seed collection, a separate botanical specimen known as a voucher is provided. Ideally this will be a dried pressed plant but high quality photographs, DNA or seed are sometimes also used. These voucher specimens are examined by taxonomists to confirm the correct name to be used initially for the seed collection, and are reviewed from time to time in response to new information about that plant group.

Assessing seeds

Once the target plant has been located and identified in the field, collectors assess whether enough plants are available which are ready to shed their seed. They use a simple cut test to estimate the amount of damaged, infested or empty seeds.

If the assessment confirms that a good quality seed collection, of sufficient quantity, can be made from a population, the collector can go ahead and gather seeds.

An NRGB expert collecting seed from wild plant populations

Once the collecting team confirms that seed from the target plant species is suitable for harvesting, they collect seed from randomly selected plants at that location. For long-term conservation, seed will be collected from at least 50 individual plants. Up to 20,000 seeds may be necessary for samples to be provided for research, so we collect from many individual plants to avoid harming the plant's future survival in the wild and do not harvest more than 20% of the available seed.

Collecting Buxus hyrcana(an endangered species) seeds in see-sangan forest

The method for harvesting seed depends on the way in which the plant species naturally disperses its seed. For example, long-handled pruners are used to collect tree seed clustered at the tip of high branches whereas fleshy fruits may be harvested individually by hand into plastic buckets. Seed dispersed by wind is often harvested by rattling branches over a large tarpaulin.

Collectors usually avoid seed lying on the ground as it may have experienced aging or insect attack since it was shed. Pressed plant specimens (herbarium specimens) are taken from one of the plants in seed to confirm identification.

Data is collected with each seed collection to provide an essential link to habitat and sampling information for the population.

Using GPS to record directions and collecting locations

It is vital that collectors keep comprehensive records of where samples were collected. This information may be requested at any point during the life of the seed collection. Collection teams use hand-held Global Positioning System (GPS) units to determine their exact location and record directions to re-find the locality. A range of ecological and sampling data is also recorded including the dominant plant species at the locality, soil type, slope, and land-use. Any features of the herbarium specimen that could be lost on pressing, such as flower color and shape, is also carefully recorded to assist in the identification of the target plant.

Recording data in collecting location

Traditionally, field data has been recorded on paper forms though teams are increasingly using electronic notebooks.

Once the seed and herbarium specimens are brought back to base the data is transferred to the gene bank database.

Seed collections must be handled carefully to maintain quality and the potential for long-term storage.

Seed collections can be harmed by poor handling in the field, and it is particularly important that seed does not experience high temperature and humidity. Collectors check the condition of seed and herbarium specimens each day. Some teams carry portable relative humidity meters to guide the handling of seed collections. If necessary, the seed is spread onto tarpaulins in a shady, well-ventilated environment to assist drying and maintain viability of the seed. Seeds within fleshy fruits are usually extracted within one or two days of collecting to reduce the risk of mould damaging the seed collection. Portable driers are sometimes used to enable rapid drying of herbarium specimens.

In general, most seed collecting expeditions last a maximum of two weeks, so that the often large number of collections can be returned to base in good condition and handed over to gene bank personnel for conservation.

If seed collections contain a significant proportion of seeds that are not fully mature, post-harvest ripening methods are used to improve seed storage potential.

Seed collections are sent back to a seed bank as quickly as possible, so that they can be dried and processed.

For most seeds, it is crucial that they are sent to a gene bank within a few days of harvesting, together with the completed field data. This will minimize any deterioration of the seed due to aging, and allow gene bank staff to check the ripeness of the collection and prepare it for drying and processing.

Accurate and careful labeling of the collection and good packing are essential, especially where seed collections are transferred to the gene bank by post or air freight. Collections of fleshy fruited species or containing moist or under-ripe seeds require careful handling before they can be safely shipped.

Seed from gene bank collectors is sent directly to Natural Resources Gene Bank (NRGB) for cleaning, processing and banking. However the majority of NRGB Project partners (Natural resource research centers) have the capacity to clean and process seeds.

Additional material from the collection such as photographs and plant specimens are sent to the NRGB, quoting the unique collection number given in the field.

 With each seed sample the following requirements must also be send to the Natural Resources Gene Bank:

1. Herbarium specimens (for deposition at the Central Herbarium of Institute of Research Institute Forestry and Rangeland)
2. Seed information:
   • data filed form (hard copy)
   • data filed form (Excel file)
3. Images:

• herbarium specimen
• plant in field
• flower

  Ø  Note 1: The maximum time between seed collecting and seed transfer to the NRGB is one month.Ø  Note 2: Required files for collection process are loaded at the under of this page. Data backups are highly recommended.Ø  Note 3: Seed package (seed accession and its accessories) evaluate in the Seed Preliminary Assessment Unit of Natural Resources Gene Bank. Report of the quality and quantity of the seed package send to the seed collector.Ø  Note 4: During the collection of a seed sample, a field code is given to each seed sample. The field code will maintain in the Gene Bank database along with other information of the seed accession. Cite the field code on the data filed form/Excel file, seed bag, herbarium specimen and images.Ø  Note 5: Before formally including a sample in NRGB collection and giving it a unique accession number, Germplasm Preliminary Assessment Unit make a series of checks of newly acquired germplasm samples to ensure that the seed sample is not duplicate.  If the seed sample also originates from one of the available seed accessions, then the newly acquired germplasm sample will be considered as a multi-year accession. However, the seed sample with different origin will introduce to the gene bank as a new seed accession.