Solving Problems
The seeds of wild plant species are more difficult to collect and conserve than those of crops. They are more likely to be short-lived or difficult to store and many possess dormancy mechanisms that ensure that they only germinate in the wild at a particular time. The MSBP has a comprehensive science and technology programme to address these problems.
Strategic and applied research is carried out in collaboration with international partners across seven themes, which align with the four main seed conservation activities of collecting, processing, storage and germination. In every case we aim to convert cutting edge science into seed conservation practice.
Collecting
Seeds must be collected at the right time for their full storage potential to be realised. Our research aims to better understand the process of seed development and how factors such as ecology, climate and seed structure affect this process over a broad range of species.
Major findings and project links:
- We have used specimen data and GIS to create collecting guides for several MSB partner countries. (See: MSB Enhancement Project Part 1A - Species Targeting)
- Research has revealed that accumulated temperature during seed development can critically affect the level of maturity at the time of dispersal and hence seed responses to drying. (See: Seed responses to climate change and environmental extremes)
Processing
Sometimes it is inevitable that seed collections contain a significant proportion of immature seeds. These seeds can be damaged or their storage potential can be reduced if they are dried too quickly. Our applied research seeks to develop post-harvest handling methods that encourage the continuation of seed maturation so that seeds enter storage with maximum storage potential.
The seeds of some species are killed by drying even when they are fully mature. Predicting the occurrence of desiccation sensitivity and its rapid diagnosis in key groups are important aspects of our research.
Major findings and project links:
- We have assessed the desiccation tolerance for > 100 dryland species as well as a selection of palms, a key 'flagship' species group (data published on 20 species). (See: Frequency of desiccation tolerance in targeted taxa)
- We developed a decision-making framework for seed handling based on seed moisture content at harvest and ambient conditions. (See: Maximising seed quality: maturity and post-harvest studies)
Storage
The storage life or longevity of seeds varies considerably across species even when they are stored under identical conditions. Knowing whether seeds are short-lived or long-lived will affect collection management including the choice of storage conditions and the frequency of seed viability testing. Our research seeks to develop new predictive models for seed longevity and diagnostic tests based on biochemical, biophysical and molecular markers. We also seek to gain a better understanding of the optimum conditions for long-term storage and the mechanism of seed ageing.
Major findings and project links:
- We revealed relationships between seed longevity and other traits, including embryo structure, climate of origin and habitat. (See: 4.1 Comparative longevity (orthodox seeds))
- We developed cryopreservation methods for storing orchid seeds with their symbionts and, separately, for an aquatic species. (See: 4.3 Maximising longevity in orchids and other socio-economically important, but potentially short-lived, species)
- We identified a universal marker for plant cell viability based on the glutathione redox state and validated its use for other systems, e.g. fungi, algae. (See: 5.2 Seed viability and ageing defined by the intra-cellular 'redox environment')
Germination
Seed banks such as the MSB conserve seeds so that the species they represent may be used in the future for restoration, re-introduction or research. Identifying optimum conditions for germination is vital both for this future use and for effectively monitoring the viability of collections during storage. Dormancy is a particular challenge when dealing with wild plant species and is therefore an important area of research for the MSB.
Practical methods for overcoming seed dormancy based on an understanding of the ecological and climatic origin of the collections are developed. In parallel we construct strategic studies with the aim to gain a better understanding of the physiological, ecological and molecular basis of dormancy.
Major findings and project links:
- We identified, by using a microarray, a number of genes likely to control the processes involved in the transition from dormant to non-dormant state. This research is carried out together with the Horticulture Research Institute (UK) and Wageningen Agricultural University (the Netherlands). (See 6.2 Molecular and biophysical dissection of changes in dormancy)
- We solved seed germination problems in MSB collections and have begun to relate seed structure to function. (See: 7.4 Role of 'underdeveloped' embryos in germination/dormancy problems)