Predicting and alleviating dormancy in challenging species: Insights and innovations from the Millennium Seed Bank Partnership

Authors:
Alice Di Sacco

Publication Date:
2019

Abstract/Summary:
The Royal Botanic Gardens Kew (UK) works with countries in the Millennium Seed Bank Partnership (MSBP) to carry out germination tests on locally sourced seed collections of wild plant species from all over the world. Germination tests are conducted after drying seeds at 15% equilibrium relative humidity (eRH) and 18°C prior to hermetic storage at -20°C. Seed dormancy, which functions to ensure seeds germinate at the best possible time for seedling establishment, represents a significant obstacle in monitoring viability in some species. Understanding how dormancy functions in the natural environment is crucial and so climate data are used for choosing dormancy breaking treatments and germination conditions. For instance, Dry afterripening (seeds held at 60% eRH and warm temperatures of c. 20°C) alleviates dormancy by simulating a dry season. In some species dormancy ensures seeds germinate sporadically over several years in nature. It is possible to shorten this time by extracting the embryo from seeds in the laboratory, as in the case of Galeopsis angustifolia, but this is time consuming and not suitable for large-scale restoration works. Move-along experimental designs, where seeds are moved through a sequence of different temperatures to simulate different seasons, are preferred. This protocol has been successfully used to propagate seeds of Adonis annua. Heat and smoke pre-treatments can also be used for breaking seed dormancy and cuing germination in restoration. Light or darkness may function as an important germination cue, such as photoinhibition of seed germination in some monocots in open, disturbed, and dry habitats.

Resource Type:
Audio/Video, Conference Presentation, SER2019

Pre-approved for CECs under SER's CERP program

Source:
Society for Ecological Restoration