Strategies and ex situ Conservation Techniques in the Cordoba Botanic Garden: the Germplasm Bank

J.E. Hernández Bermejo & M. Clemente Muñoz

Jardín Botánico de Córdoba
Avda de Linneo s/n., 14004 Córdoba, Spain

Abstract

Amongst its conservation programmes, the Cordoba Botanic Garden includes the management of a Plant Germplasm Bank (PGB). This institution established the priorities and objectives of the PGB after having studied the degree of threat to the Andalusian flora. Among the autochthonous wild species, special attention was paid to those under risk of extinction and to those included in the regional or national red data books and in international conventions. As for the wild plant genetic resources of the region, priority is given to those species with potential horticultural interest (wild relatives of the cultivated species, species of ethnobotanical interest, lost or neglected crops, etc.).

A part of this Plant Germplasm Bank is the result of a regional strategy coordinated with the Andalusian Environmental Agency, the official institution of the Andalusian Autonomous Government responsible for nature conservation. Other objectives of a wider geographical scope are also followed, through coordinated programmes with the institutions involved at state level (the National Institute for the Conservation of Nature and the National Commission for Technical and Scientific Research) or through European Union projects.

The conservation methods include not only the management of seeds previously dried in cold chambers for short and long term storage (at -5°C and -15°C) but also the in vitro conservation of clones and greenhouse collections. The PGB extends its methods and objectives using part of the material for the study of the propagation systems of certain species, to include maintaining ex situ populations for exhibition in the Botanic Garden and for developing and applying integrated restitution techniques in the recovery plans of endangered species carried out by the Andalusian Environmental Agency.

The artificial propagation of an endangered species is the best way to save it from extinction, especially if its wild populations are under exploitation. However, not only the species themselves should be the main beneficiaries of the conservation work, but also the local communities close to the natural habitats of these species. In this way the local farmers will have the satisfaction of conserving their biological heritage, and at the same time they will receive the economic benefits obtained from its cultivation.

Resumen

El Jardín Botánico de Córdoba incluye entre sus métodos y programas de conservación el manejo de un Banco de Germoplasma Vegetal (BGV). Este BGV nace de la aplicación de una estrategia regional, coordinada con el organismo oficial de la Comunidad Autónoma de Andalucía responsable de la Conservación de la Naturaleza (AMA). Tras una fase de evaluación de recursos, especies en peligro y después de priorizar objetivos, el propio Jardín Botánico dirije la actividad de su BGV en función de criterios priorizados regionalmente. Otros de ámbito geográfico más amplio son complementariamente atendidos mediante programas coordinados con los organismos responsables a nivel de estado (Instituto para la Conservación de la Naturaleza (ICONA)) o a través de projectos de la Comunidad Económica Europea (CEE).

Los métodos de recolección utilizados distinguen el caso de especies en peligro de extinción del caso más general, en el que por no existir este riesgo, las colectas pretenden incluir la máxima biodiversidad posible (niveles alfa, beta y gamma). Los métodos de conservación contemplan no sólo el manejo de semillas predesecadas en cámaras frigoríficas a medio y large plazo ( 5°C y 15°C) sino también la conservación in vitro de clones y de colecciones en invernadero. El BGV prolonga sus métodos y objetivos utilizando parte del material conservado en la investigación de los sistemas de propagación de ciertas especies, en la obtención de poblaciones ex situ para su exhibición en el Jardín Botánico de Córdoba o para el ensayo y aplicación de técnicas de restitución integradas en los planes de recuperación de especies amenazadas que la Comunidad Autónoma Andaluza ha puesto en marcha.

Los taxones conservados en el BGV son el resultado de la prioriación de objetivos establecida en la estrategia regional. Así, dentro de las especies silvestres autóctonas, se atiende especialmente aquellas en riesgo de extinción y las incluidas en libros rojos de carcáter regional, nacional o en convenios internacionales (Berna, CITES, etc.). Dentro de los recuros fitogenéticos silvestres de la Comunidad el BGV prioriza también aquellas especies de interés potencial agrícola (parientes próximos a las cultivadas, especies de interés etnobotánico, cultivos marginados u olvidados, etc.).

Los administradores del BGV del Jardín Botánico de Córdoba consideran que poner en cultivo una especie es la major forma de salvarla de su extinción, especialmente, si sus poblaciones silvestres se hallan sometidas a extracción. Pero ésto debe ser compatible con que la propia especie sea la principal beneficiada de los trabajos de conservación y con que la comunidad de origen (autonomía, etnia, región o estado) reciba no sólo la satisfacción de conservar su patrimonio biológico sino también parte de los beneficios generados por su explotación.

Introduction

The Germplasm Bank of the Cordoba Botanic Garden was started soon after the Garden itself. The Botanic Garden was conceived and set up in 1980 as an institution dedicated to the conservation of the plant resources of its regional community and to the dissemination of the value and interest that plants have for human beings. Consequently the facilities needed for the development of a conservation programme were provided. The design of a germplasm bank included the installation of cold chambers, propagation greenhouses, culture chambers, and an in vitro culture laboratory, etc. Simultaneously with the development of these facilities, some expeditions for the collection of germplasm were carried out. Meanwhile this germplasm was stored in an upright freezer of the Agricultural Botany Unit (Department of Sciences and Forest and Agricultural Resources, University of Cordoba).

Since its creation, the Germplasm Bank has acquired a regional commitment to preserve the very rich, but at the same time endangered, Andalusian flora. This richness comprises not only the biodiversity of its autochthonous flora but also its ethnobotanical heritage, its agricultural resources and even the singularity of some elements of its allochthonous flora.

Objectives for and Development of a Regional Germplasm Bank

Andalusia makes up the southern third of the Iberian peninsula, with an area of 8 726 700 ha. Its autochthonous vascular flora is formed by around 4000 taxa at the species and subspecies level. Of these, 1074 are either endemics or taxa with a narrow distribution, 926 are dicotyledons (Magnoliopsidae), 103 monocotyledons (Liliopsidae), 8 gynosperms and 37 ferns. Considering the IUCN categories, the greatest risks of extinction (combination of the E and Ex categories) affect a total of 68 taxa, 35 of which are specific and narrow Andalusian endemics (NE), 14 are endemics at a wider level (WE) (Iberian, Andalusian-Tirrenic or Andalusian-Northafrican) and 19 are species with a wider area of distribution that are very endangered in Andalusia (wa). There are 102 vulnerable species and 430 rare species. The number of taxa exclusively endemic from Andalusia is 484, and other 465 taxa are endemic at a wider level (see Table 1).

In short, more than 1000 taxa at the species or subspecies level need to be protected, either for being subject to severe threats of extinction or for their narrow area of distribution.

An area of 1 497 195 ha is already protected in Andalusia, which is around 17% of the Andalusian territory. The Andalusian network of natural areas is the biggest one of all the different regional networks presently existing in Spain. Nevertheless this fact is not enough guarantee the conservation of all the taxa in need of protection. Many of them are located outside the Natural Parks or Reserves and, in any case, the in situ measures now being carried out are not enough to assure the conservation of these taxa by means of this method alone. The application of ex situ techniques is required to complement and strengthen the in situ techniques. These are the reasons for the existence of a Plant Germplasm Bank and an ex situ conservation programme with a regional tendency in the Cordoba Botanic Garden. This programme has been carried out in cooperation with the Environmental Agency of the Andalusian Autonomous Government since 1988. It is also coordinated with other Andalusian research groups through the in situ rescue plans for Andalusian endangered species that were initiated by the Environmental Agency in 1992.

Table 1. Distribution of the Andalusian wild vascular taxa according to the extent of their distribution and their risk of extinction (Hernández Bermejo, E., Clemente Muñoz, M. et al. 1993).

Andalusia also possesses a great ethnobotanical heritage. Some of its regions are rich both in traditional knowledge and in plant resources of ethnobotanical interest (for their medicinal or food properties, crafts, folklore, rural or agricultural building, etc.). In this sense, the following areas are worthy of mention: Las Alpujarras, in Sierra Nevada; Valle de los Pedroches, in Sierra Morena; Serranías de Ronda and Grazalema; Axarquía in Malaga, Sierras de Cazorla and Segura, etc.

In a study carried out by González Tejero, M.R. (1989) in Las Alpujarras, 241 species of medicinal use were identified, of which 49 were referenced for the first time as regards their properties and uses. Many of these species are specific Andalusian endemics such as Sideritis glacialis, Pterocephalus spathulatus, Digitalis nevadensis, or Artemisia granatensis.

The use and applications of many wild species in different areas of the province of Cordoba is described in recent works carried out by Casana Martinez, E. (1993) and Galan Soldevilla, R. (1993). Some allochthonous species such as Arundo donax, Celtis australis or Ceratonia siliqua have given rise to traditional uses and have developed an original germplasm. However, this germplasm has sometimes been subject to extinction processes, as in the case of Aloe vera. Certain cultivated species (olive tree, cork oak, vine) originate, independently of the main benefits obtained from their cultivation, a series of marginal uses of traditional nature. Some crops have wild relatives in the region, thus requiring special consideration in the management and conservation programmes (for example, certain species of the genera Cynara, Allium and Beta). There are also plant resources with a promising potential, as in the case of some species with forage, oleaginous and bioenergetic interest such as Onopordum nervosum or Carthamus arborescens. Finally, it should be emphasized that the great diversity of the allochthonous wild flora, especially among the ornamental species, is the result of a long and complex process of introductions and exchanges with Asia, Africa and America. Some examples are: Ceratonia siliqua, Ficus carica, Celtis australis, Ricinus communis, Asclepias curassavica, Opuntia ficus-indica, Agave americana, Phytollaca americana, Bidens aurea, etc.

Previous experience in the management and design of this type of facility had been acquired by some of the members of the scientific staff of the Cordoba Botanic Garden in the Germplasm Bank of the Polytechnic University of Madrid. For this reason, the Plant Germplasm Bank at Córdoba was initially conceived as a simple seed bank. The seeds are dried with blue silica gel and then stored in cold chambers (- 5°C and - 15°C).

However, the concept of the Seed Bank soon started to be redirected according to the guidelines of a modern botanic garden. Live collections and ex situ populations were developed, considering aspects such as its infraspecific variability or genetic origin. One of the most traditional activities of a botanic garden has been carried on since 1982: the exchange of seeds through an Index Seminum. Some ethical and strategic problems arose: it was not logical to replenish the germplasm of rare or endangered taxa year after year from nature, to send it to other institutions or researchers. In this sense the aim of the Seed Catalogue was changed in 1991 (Clemente, M. & Contreras , P. 1990). Since 1991, the Catalogue has become a coordinated task of the botanic gardens of the Iberian-Macaronesian Association. As a result of this coordination between the different catalogues, less effort, better quality and a minimum sacrifice of nature are achieved. The Bank has also been used to replenish the collections for exhibition and education. It was no longer a static collection or accumulation of plant material, and constant management was immediately required.

On the other hand, the development of research programmes on propagation and conservation techniques of endangered species gave a new dimension to the Bank. So in vitro culture methods and facilities were created in the Garden in 1988 (Clemente, M. 1991) and at the same time some procedures for the restitution and domestication of these species were developed. Some of them could not be stored as seeds, and so have been conserved in the in vitro collections. The Plant Germplasm Bank was no longer a simple Seed Bank.

Results

Some objectives and priorities were established in order to determine the type and size of the facilities required, methodology to be used and type of material to be conserved. Three parameters were used: nature of the taxa to be conserved, form of the plant material, and geographical area where work should be carried out.

As a result, a seed bank was created for the conservation of orthodox seeds in cold chambers at - 5°C and - 15°C as well as an in vitro culture unit for those species in need of micropropagation or for which it was advisable to maintain collections of clones by means of tissue culture.

These ex situ conservation techniques are applied to species with one or some of the following characteristics: endangered species; species with a past, present or future local importance; species of ethnobotanical interest; species of interest for the restoration of local ecosystems; emblematic local species; taxonomically isolated species and monotypic or oligotypic genera.

The geographical area of work is mainly focused on the conservation of taxa from Andalusia and surrounding territories.

The general catalogue of species recommended for protection in Andalusia has been published (Hernández-Bermejo, E., Clemente Muñoz, M. et al. 1993), and it has been possible to establish different levels of priority for the protection of the flora at a regional level.

In December 1993 the Seed Bank had 3205 accessions of 1474 different taxa (species and subspecies). Several collections are being incorporated through cooperative programmes with different national and international institutions since 1980, for example: taxa of potential agroenergetic interest (Scientific and Technical Research Committee); Iberian endangered endemic taxa (Plant Germplasm Bank of the Polytechnic University of Madrid); taxa of wide distribution with ethnobotanical interest (Scientific and Technical Research Committee); Mediterranean taxa of wide distribution with aromatic interest (European Community - MEDSPA); taxa of the Alpine Garden in Sierra Nevada (University of Granada) and Meridional-Iberian taxa from non-Andalusian territories (National Institute for the Conservation of Nature).

The information about these taxa is registered in a database, including: accession number, taxonomy, locality of collection, distribution, UTM coordinates, collectors, IUCN category, date of storage into the cold chamber, stock at that date, present stock, location in cold chamber, programme to which every accession belongs, etc.

A seed exchange has been maintained through the catalogue since 1982. Some 800 catalogues are sent annually offering material to botanic gardens and similar institutions throughout the world. More than 27 000 samples have been requested from 400 institutions of 48 different countries.

Collections are subject to periodical tests to check their viability. Several germination tests are made following different treatments under controlled conditions.

It should be emphasized the creation of the Andalusian Germplasm Bank has been the result of a cooperative programme between the Andalusian Environmental Agency and the Cordoba Botanic Garden. The objective of this programme is the study and conservation of the Andalusian wild plant resources that are considered as rare, vulnerable or under risk of extinction. This singular collection had 774 accessions of 422 different taxa by December 1993.

The in vitro culture technique has been applied to some Andalusian species, such as Artemisia granatensis, Iberis nazarita, Aquilegia cazorlensis, Sempervivum nevadense, Centaurea carratracensis, Staehelina baetica, Astragalus nevadensis, Rosmarinus tomentosus, Betula pendula fontqueri, Taxus baccata and several species of the genus Narcissus.

Micropropagated materials are being acclimatized in protected areas close to their natural habitats in order to, in some cases, domesticate and cultivate the species. This way, plant resources from artificially propagated materials could be used with a double aim: to avoid their extraction from nature and to obtain income for the local farmers who could eventually become spontaneous guardians of those resources in nature, as has happened in similar situations of the cultivation of endangered species carried out in other countries (Vovides, A.P. & Iglesias, C.G. 1994).

Conclusions

The installation and development of a germplasm bank at a regional level has been a remarkable ex situ conservation strategy, taking into account the rich plant biodiversity of Andalusia and the degree of threat to which a fourth part of its flora is subject.

The cooperation and support from different national and international institutions has been a major factor in the successful development of different conservation collections.

The programme - carried out jointly with the Environmental Agency of the Andalusian Autonomous Government management authority for the protection of the regional flora - is clear evidence of how an official institution can promote and encourage not only in situ conservation, but also ex situ conservation in cooperation with other public institutions, in this case the Cordoba Botanic Garden. The combination of both techniques assures an effective conservation of the wild plant resources, which are more and more threatened in their natural habitats by fires, habitat transformation, extraction, etc.

The conservation of endangered wild resources should be carried out not only for its intrinsic value. Rescue plans for species should include not only their safeguarding, but also their artificial propogation by local farmers. By doing this, the local community will feel itself involved in the conservation of its phytogenetic heritage and will receive the economic benfits obtained from the exploitation of the resources under cultivation.

References

Casana Martinez, E. (1993). Patrimonio etnobotánico de la Provincia de Córdoba: Subbética, Campiña y Vega del Guadalquivir. Universidad de Córdoba, Córdoba.

Clemente Muñoz, M. & Contreras Garcés, P. (1990). Hacia un nuevo concepto de index seminum. In: Libro de Res˙menes V Congreso Latinoamericano de Botánica. La Habana, Cuba.

Clemente Muñoz, M. (1991). The Micropropagation Unit at the Córdoba Botanic Garden, Spain. Botanic Gardens Micropropagation News 1: 30-31, Kew, UK.

Clemente Muñoz, M. et al. (l991). Micropropagation of Artemisia granatensis Boiss. Hort. Science 26: 420.

Galan Soldevilla, R. (1993). Patrimonio etnobotánico de la Provincia de Córdoba: Pedroches, Sierra Norte y Vega del Guadalquivir. Universidad de Córdoba, Córdoba.

González Tejero, M.R. (1989). Investigaciones etnobotánicas en la provincia de Granada. Universidad de Granada, Granada.

Hernández Bermejo, E., Clemente Muñoz, M. et al. (1993). Protección de la Flora en Andalucía. Junta de Andalucía. Consejería de Cultura y Medio Ambiente. Agencia de Medio Ambiente, Sevilla.

Vovides, A.P. & Iglesias, C.G. (1994). An integrated conservation strategy for the cycad Dioon edule Lindl. Biodiversity and Conservation 3: 137-141.


Fig 1. Indices Seminum and containers for seed storage at Cordoba Botanic Garden


Fig 2. Cold chamber at -5 °C at Cordoba Botanic Garden.


Fig 3. Seeds in hermetic containers, in cold chamber at -15 °C at Cordoba Botanic Garden.


Fig 4. In vitro Culture Unit at Cordoba Botanic Garden. Transfer of plant material to culture media in the laminar flux cabinets.

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