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Seed conservation of China’s flora through the Germplasm Bank of Wild Species

Volume 12 Number 1 - January 2015

Jie Cai

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Introduction

Ex situ conservation has been widely adopted as a plant conservation practice. Seed banking, as a cost-efficient conservation tool, was initially introduced for preserving crop seeds. Over the past 15 years, this “dry-out” and “freeze-up” seed conservation technique has been widely adopted in many countries to safeguard wild plant species, propelled by Millennium Seed Bank Partnership (MSBP) of the Royal Botanic Gardens Kew (RBG Kew). The Germplasm Bank of Wild Species (GBOWS) was established in 2008 at the Kunming Institute of Botany (KIB), Chinese Academy of Sciences. It is the biggest germplasm conservation facility for wild species in China and host to China’s biggest seed bank, playing an important role in the face of biodiversity loss due to dramatic environmental change and the fast-growing economy. As an ex-situ conservation facility located in a global biodiversity hotspot, it aims to address the loss of China’s biological heritage.

Background

There are about 31,000 vascular plants recorded in China, of which around 50% can be found nowhere else in the world (Wu et al., 2013). China is also home to 7,516 vertebrates, including 1,269 different kinds of birds (Ministry of Environmental Protection, 2013). China harbors four of the 34 global biodiversity hotspots, in which the Mountains of Southwest China and the Himalaya are centers of distribution of many important species, e.g. Tibetan antelope (Pantholops hodgsonii), giant panda (Ailuropoda melanoleuca), rhododendron (Rhododendron spp.) and primrose (Primula spp.). The northern hemisphere’s largest evergreen broadleaved forest ecosystem is located in south and southwest China, greatly contributing to the diversity of the country’s flora and fauna.

However, China’s wilderness and biodiversity are coming under increasing threat from rapid economic growth. Intensification of agriculture, large development projects, the over-harvesting of timber and medicinal plants all contribute to this threat.  The conservation of China’s unique genetic resources is therefore of great necessity and urgency to support the sustainability of the nation. The GBOWS project was conceived and proposed in 1999 by Prof. WU Zhengyi, a prominent botanist from KIB. It aims to preserve and carry out research on the germplasm of China’s native plants, animals, microbes and fungi. The main building of GBOWS was built and functioning by 2008 with three preservation facilities—the seed bank, the in vitro plant germplasm bank and the plant DNA bank. The microbial germplasm bank and the animal germplasm bank are located at Yunnan University and Kunming Institute of Zoology, CAS respectively, as subsidiary sections of the GBOWS project.

Target and progress

The seed bank is the core conservation facility of GBOWS, with the target of preserving 100,000 accessions of 10,000 species from China by 2020. China’s plant species that are threatened, endemic and economically important are prioritized for collection. By the end of 2014, GBOWS’s seed collections reached 65,067 accessions of 8,855 species,

30% of China’s seed plants have been conserved in its national seed storage facility.”

Conserved species have been collected from different climatic zones and vegetation types across China, from the arid Gobi desert to temperate forests in Northeast China, and from the Himalayan alpine scree slopes to tropical jungles. Of particular note are the 15,018 accessions representing 4,900 species that have been collected from the Qinghai-Tibetan Plateau. This is thought to be one of the most species-rich places in China, but also one of the most vulnerable to climate change. Tibet represents about half the size and includes all the landscapes of the Qinghai-Tibetan Plateau. Although there are more than 40 nature reserves established in Tibet, there are no botanical gardens or seed banks. The seed collection held in GBOWS is important to fill the gap in ex-situ conservation of Tibetan plants.

GBOWS’s seed preservation facilities were designed and are managed according to international standards. Collected seed is dried in the drying facilities at a temperature of 15℃ and 15% relative humidity and then sealed in containers or foil bags, before being transferred to the freezer-like cold room which is maintained at -20℃, for long-term storage. As the biggest regional seed bank for wild species, GBOWS is capable of providing seed storage services for its national and international counterparts (see Table 1) to back up their seed collections in a secure condition. By the end of 2013, 1,256 seed collections from several organizations in-country and abroad have been duplicated in GBOWS.

Networking and training

To preserve China’s mega-flora and achieve the ambitious seed conservation target before 2020, GBOWS could not work alone. GBOWS has therefore developed a nationwide seed-collecting network. This includes 71 organizations, research institutes, universities and nature reserves that are actively collecting seeds from their local flora for long-term conservation. Furthermore, young researchers, forestry staff and students involved in seed collecting programmes are trained in seed conservation theory and techniques through regular training courses, workshops and field practice. In Yunnan province, more than 50% of the nature reserves have sent their staff to attend the annual “seed conservation techniques” training course. Through this, many in situ conservation practitioners have learnt about ex situ conservation theory and now understand the procedures of seed conservation. In the past 8 years, over 400 people have received seed conservation techniques training delivered by staff from GBOWS and its international collaborators including the Millennium Seed Bank Partnership.

Seed science research

The massive number of seed accessions held in the GBOWS seed bank counters the loss of China’s plant diversity. It also provides a great opportunity to enhance understanding of China’s plant resources through additional seed information, such as seed morphology, germination and dormancy. GBOWS’s germination team generates data from around 8,000 germination tests every year, to monitor collection quality and improve species germination practices. Moreover, the seed biology research capacity at GBOWS was built up through studies of seed storage behavior, especially of threatened species. There are also comparative seed studies conducted in collaboration with other seed biologists worldwide. For example, it has been reported that seed collections from alpine regions in Europe are short-lived and can only survive in seed bank conditions for a few years. There is similar research work ongoing at GBOWS to verify this hypothesis with China’s alpine species.

Future perspectives:  DNA barcoding and seed collection

For best practice, it is important to have every seed collection verified with the accurate species name. However, this can sometimes be difficult if the taxonomic characteristics of the target species are not present when the seeds are harvested.  It is even more tricky if the targeted species and its close relatives exist in the same area. For example, Pedicularis is the third biggest genus in China with 352 species recorded in the Flora of China.  Two-thirds of these species can be found in the Himalayan-Hengduan Mts. Region. In the alpine meadows of northwest Yunnan, it is common to find different species of Pedicularis mingling together and more or less sharing similar phenology. It is very difficult to tell one from another during the seed collecting season. However, with the development of plant DNA barcoding techniques, it is possible to identify the seed collections by the use of molecular tools. The latest research on the DNA barcoding of Pedicularis by KIB’s researchers found that it is possible to discriminate this big group at species level by certain DNA barcodes (Yu et al., 2011). This will make identification efficient and accurate and provide the seed collections with accurate names for future utilization. It is expected to expand the DNA barcoding techniques for verification of a greater number of seed collections.

References

Ministry of Environmental Protection. 2013. Report on the State of the Environment in China 2013 (in Chinese).

WU, Z.Y., Raven, P.H., Hong D.Y. eds. 2013. Flora of China, Volume one. Beijing and St. Louis, MO: Science Press and Missouri Botanical Garden.

Yu, W.B., Huang, P.H., Ree, R.H., Liu, M.L., Li, D.Z. and Wang, H. 2011, DNA barcoding of Pedicularis L. (Orobanchaceae): Evaluating four universal barcode loci in a large and hemiparasitic genus. Journal of Systematics and Evolution, 49: 425–437.