Safe for the future: seed conservation standards

Elinor Breman reflects on the development and implementation of seed conservation standards across the Millennium Seed Bank Partnership network.

Millennium Seed Bank at Wakehurst

Kew’s Millennium Seed Bank Partnership

Kew’s Millennium Seed Bank Partnership (MSBP) is the largest wild plant conservation programme in the world. Now in its 15th year, the MSBP covers 84 countries and more than 200 organisations. As networks grow, so does the need to standardise operations across them; the MSBP Seed Conservation Standards were developed to meet this need.

Science-based conservation

The MSBP came into being in response to the growing awareness of the importance of ex situ conservation of plants. It focuses purely on non-crop species, which account for more than 99% of plant diversity. In order to conserve seed from these species, the MSB has developed an active research methodology that informs all aspects of seed conservation. For example, in the field we ensure the genetic diversity of the population is captured without endangering the source population, whilst back in the lab our germination tests following cold storage ensure our banked collections are viable.

Why is this important? Science-based conservation enables the highest quality seed collections to be made, ensuring the maximum longevity of seeds held in the seed bank, where seeds are dried, placed in sealed containers and stored at -20°C. This in turn assures the quality of the collections to end users for research purposes or conservation programmes. This allows the MSBP to fulfil its integrated conservation strategy, with ex situ long-term conservation of seeds supporting in situ conservation actions.

Working with partners

The basic model of the MSBP is for partner organisations to send half of their seed collection of a given species to the MSB for safe storage. Increasingly, partners in the MSBP are duplicating in national or regional seed banks, not at the MSB. This is fantastic, and shows that the partnership is really working, but it leads to the need to ensure that the same international standards are being met at all the institutes across the Partnership (the MSB included). Using standards in seed banks around the world is key to assuring high quality global seed conservation at the scale required by current plant conservation targets (for example the Global Strategy for Plant Conservation).

Seed banking standards have been in existence for some time, for example FAO, ISTA. However, these have tended to focus on crop species and other economically important plants where banking is short-term. The situation is subtly different for wild plant species and long-term conservation storage (10s-100s of years) and so the MSB developed the Seed Conservation Standards, which can be found on Kew’s website. The MSBP Standards cover all aspects of seed conservation from collection through to seed bank management, and provide a framework to enable MSB partners to achieve high quality collections.

Turning science into practice

As an example of the science behind the MSBP Standards, let’s look at MSBP Standard 1.3 under Collecting, which reads: 

1.3 Genetic diversity of sampled population is adequately represented

For seed conservation it is important that the genetic diversity of the source population be adequately represented in the seed sample collected. These seeds are being held with a view to their use in research and in situ conservation efforts, and it is essential that the genetic makeup of the seed sample users receive matches that of the original population. We do not know what plant characteristics will be important under future environmental and climatic scenarios, and by conserving the range of genetic variation available in a population we are building the maximum possible resilience into our collections, helping them to meet future needs.

MSBP Standard 1.3 may sound simple, but the science behind it is complex, and putting it into practice in the field can be challenging. First, you need to define your population and the number of individuals within it; this can be tricky where vegetation or the landscape obscures your view, and where sub-populations exist. Second, you need to ensure that you have collected 95% of the commonly occurring alleles (different forms of a gene) within the population by collecting from 30 individuals in an outbreeding population, and 59 in an inbreeding species (Brown & Marshall, 1995). As the breeding system may be unknown, it is recommended that seeds are collected from a minimum of 50 plants spread across the population. Data relating to the size of the population, the number of individuals in seed and the number of individuals collected from must be recorded to demonstrate that this MSBP Standard has been met.

Implementation of the MSBP Standards

The MSBP Standards have been well received by the MSBP community. In our annual questionnaire in 2014, the year the MSBP Standards were introduced, 86% of those who responded wanted to be further involved with the development and monitoring of the MSBP Standards. We also gauged how easy our partners felt the various MSBP Standards would be to meet.

The majority felt that the MSBP Standards would be easy to meet, notably those associated with collecting, while those associated with viability and monitoring would be harder to meet. This year our questionnaire revealed that 88% of respondents felt that their institute was ready for a full MSBP Standards assessment in the coming year.  

How do we capture information for a Standards assessment?

Assessing the MSBP Standards involves auditing both procedure and protocol, as well as the technical capacity and facilities of a seed bank. We have developed a monitoring form which partners fill in and can discuss via email and conference calls, or a member of staff from the MSB can visit the partner institute to carry out the assessment with them. We also use the MSBP Data Warehouse, a BRAHMS database storing seed collection data from across the partnership, to assess the MSBP Standards. The data held can be used to assess 60% of the MSBP Standards, which is incredibly helpful when we work with so many organisations around the world. The database is able to calculate scores for each of the data-based MSBP Standards and then amalgamate these to form an overall institute score for each of these MSBP Standards – hugely reducing the workload for our staff.

The MSBP Standards are not compulsory, but their uptake across the network has been phenomenal. They provide a tool for all the seed banks in the partnership, including the MSB, to identify their individual strengths and weaknesses and work towards improving the quality of their collections.

Next steps

The MSBP Seed Conservation Standards represent an important step forward for ex situ plant conservation. Over the next few years we will be increasing the number of assessments carried out across the MSBP. Not only will this provide a quality assurance for the collections held in this network, it also provides a platform for technology transfer and capacity development to improve collection quality at all partner institutes.

Read & watch