build up capacity
Ex situ collections hold the key Dr Emma Dalziell Research Scientist Dr David Merritt Research Scientist Dr Bryn Funnekotter Research Scientist Dr Eric Bunn Research Scientist
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x situ conservation, the conservation of species and their genetic diversity ‘off-site’ or away from the natural habitat, is a core function of many botanic gardens. Ex situ conservation encompasses a range of techniques and technologies to collect, store, study and use plant material. At Kings Park, ex situ conservation has been undertaken since the 1960s, when the seed bank was established to support the creation of the Botanic Garden. Today, the ex situ conservation programs include seed banking, tissue culture, cryopreservation and plant collections within the display gardens. Ex situ conservation is an important strategy to prevent the loss of biodiversity from a myriad of threats in the plant’s natural habitat. It also plays a major role in supporting ecosystem restoration and rare species translocations. Genetically and geographically representative collections of seeds can be sourced and banked over many years to build sufficient stocks for restoration.
Inside the Western Australian Seed Centre vault at Kings Park where the seeds of 3,800 Western Australian native species are stored at -20°C. Photo: Dave Blumer
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For People & Plants | Special Issue | Spring 2021
Plants grown from seeds or vegetatively through tissue culture can be used as founder material to develop seed orchards where seed supplies are limited. The collections provide opportunities to research plant biology, propagation and establishment requirements, pests and disease resilience, climate change resilience and adaptation, and many other factors that contribute to restoration success. The largest ex situ collections are held in the seed bank of The Western Australian Seed Centre. Seeds are sourced from across WA, including locally, where seeds assist bushland restoration in Kings Park and Bold Park. More than 300 of these bushland species are stored in the seed bank and are used for urban bushland restoration. Kings Park has worked for more than 20 years as part of national and international collaborative conservation initiatives through the Australian Seed Bank Partnership and the Millennium Seed Bank Partnership. These partnerships have resulted in collections of more than 2000 WA species, with most duplicated at the Millennium Seed Bank in the Royal Botanic Gardens, Kew. The tissue culture collection houses 47 rare and threatened species with more than 200 clonal accessions capturing some of the genetic diversity. This collection began in 1982 and has close to a thousand collections with a hundred species successfully initiated into tissue culture. The Grevillea scapigera collection (See page 16) is of particular importance to translocation where 25 different accessions of this threatened species were collected. The tissue culture collection supports species conservation and restoration, with collections made from a wide range of genera, including the carnivorous species Aldrovanda vesiculosa. Cryopreservation (storage of plants in liquid nitrogen, temperatures below -130°C) provides a long-term conservation option for these species in tissue culture, as well as a backup for collections in the seed bank. Cryopreservation collections began in 1992 and now include collections of seed, shoot tips from tissue culture material and symbiotic fungi for the orchid collection. Ex situ methods provide an important component of plant conservation and restoration, however, our knowledge of how plant material responds to ex situ storage conditions is still limited due to the number and diversity of our native flora.
