Conservation Of Forest Genetic Resources Research Articles

Choices for tree conservation

Choices for tree conservation

Vitrification, a complementary cryopreservation method for Betula pendula Roth

Cryopreservation—the storage of plant germplasm in liquid nitrogen—provides a modern tool for the conservation of forest genetic resources. It is especially applicable for species in which their micropropagation can be initiated from mature tree buds, e.g., silver birch ( Betula pendula Roth), thus enabling the conservation of specific genotypes: endangered elite trees and trees expressing rare, valuable or interesting characteristics. The aim of the present study was to develop a vitrification protocol applicable for the cryostorage of silver birch that avoids the use of expensive sophisticated freezers. The average recovery of vitrified axillary silver birch buds was 71% using a protocol that started with four-week cold hardening of bud-bearing in vitro donor shoots on modified medium under short day conditions. After cold hardening, the excised axillary buds were precultivated on medium containing 0.7 M sucrose for 24 h under the same conditions as during the cold hardening period. Following preculture, the buds were treated with loading solution containing 2 M glycerol and 0.4 M sucrose for 20 min at room temperature. Finally, the buds were dehydrated with PVS2 cryoprotectant for 120 min followed by direct immersion in liquid nitrogen. According to the morphology and the RAPD profiles of regenerated plants in the greenhouse, the genetic fidelity of the vitrified birch material seems to have remained unchanged.

The differences among hairy and typical European black poplars and the possible role of the hairy type in relation to climatic changes

The hairy type of black poplar ( Populus nigra ssp. caudina) growing along the Neretva river (Bosnia and Herzegovina) differs considerably from the black poplar in the riparian populations along the rivers Danube, Drava and Sava in Croatia. This rare hairy type of P. nigra, considered to be a tertiary relict and a xeromorphic form in the sub-Mediterranean region, was compared to the typical European black poplar with the discriminant analysis. The analysed species differ significantly in all five investigated morphological traits. The possible role of the hairy black poplar in the conservation of forest genetic resources of black poplar in relation to climatic changes was discussed.

Forschung zur Vielfalt, vielfältige Forschung: Ziele und Wege der Forstgenetik | Research on diversity, diverse research: objectives and approaches in forest genetics

The genetic information about forest trees is not only of crucial importance for the yield of forestry production systems,but also for determining the evolutionary adaptive potential of tree populations. Thus, the stability of forest ecosystems depends on the sustainable management of forest genetic resources. In this context, tree breeding and conservation of forest genetic resources are mentioned as main applications of research in forest genetics. Genetic inventories are conducted in order to observe the spatial distribution of genetic information at gene marker loci. Such studies allow us to elucidate the evolutionary history of populations and, thus, to draw conclusions about their evolutionary adaptability. Results of a genetic inventory of oak (Quercus spp.) populations native to Switzerland are presented, and their significance for the characterization of genetic systems and adaptive potential is discussed. Future research into forest genetics should aim at improving our understanding of the relationship between variation at biochemical and molecular marker loci and adaptive processes in forest tree populations. The temporal dynamics of genetic structures of forest tree populations as a consequence of anthropogenic environmental change is another important topic of forest genetics in particular for the conservation of rare species.

Challenges and opportunities for conservation of forest genetic resources

Increased use of forest resources and a shrinking forestland base threaten the sustainability of forest genetic resources and highlight the importance of conservation and sustainable management of these resources. As forest trees are normally the keystone species of forest ecosystems, their continued existence is essential for many floral and faunal associations of these ecosystems. Major concepts, challenges and opportunities for conservation of forest genetic resources are briefly discussed in this paper. The major challenges include population decline and population structure changes due to forest removal and conversion of forest land to other uses,forest fragmentation, forestry practices, climate change, disease conditions,introduced pests, atmospheric pollution, and introgressive hybridization. Developing scientifically sound conservation strategies, maintaining minimum viable population sizes, and deployment of genetically engineered organisms represent other important challenges in conservation. The usefulness of various biochemical and molecular genetic markers, adaptive traits, and genetic diversity measures for developing conservation strategies for in situ and ex situ genetic resource conservation are also discussed. Major opportunities for conservation of forest genetic resources include: use of molecular genetic markers and adaptive traits for developing conservation strategies; in situ conservation through natural reserves,protected areas, and sustainable forest management practices; ex situ conservation through germplasm banks, common garden archives, seed banks, DNA banks, and tissue culture and cryopreservation; incorporation of disease, pest, and stress tolerance traits through genetic transformation;plantation forestry; and ecological restoration of rare or declining tree species and populations. Forest genetic resource conservation and resource use should be considered complementary rather than contradictory to each other.

Legislation of Forest genetic resources conservation in Spain

The history of forest conservation in Spain began with the first forest regulation dated 1575. Recently, the International Agreements endorsed by Spain, including the Agreement on Biological Diversity (Rio, 1992) and the pan-european conferences on the protection of forest (Strasbourg, 1990, Helsinki, 1993, Lisbon, 1998) are the main foundations for the protection of forest in Spain. Although no specific legislation on forest genetic resources conservation have been established in Spain, the National Forest Strategy and the Forest Plan (coordinated by the Ministry of Environment) are the main documents to base future actions related to conservation issues.

The role of biotechnology in forest genetic resource conservation

In today’s world, in which the increasing demand of agricultural products and the changing needs of raw materials and environmental pressures are threatening all natural ecosystems, particularly the forest ecosystems, is specially important the knowledge and conservation of forest resources. Biotechnology offers new tools for complementing classical Forest Tree Improvement methodologies in order to manage Forest Genetic Resources (FGR). The impressive achievements of the techniques of Molecular Biology and Plant Tissue Culture in the last two decades are in the background of the development of fields such as DNA markers, tree genomics, genetic transformation, criopreservation and plant regeneration (expression of cellular totipotency). Particularly suitable for application to genetic resources are DNA markers, so that the nature, extent and distribution of natural variability of plant species can be assessed at the genome level, and therefore aiding in decisions about what and how to conserve. Criopreservation and plant regeneration are useful to conserve and micropropagate specific plant material for ex situ conservation and developing high-value clonal forestry. Different applications of these tools to forest trees are reviewed. The research work of Spanish groups dealing with Iberian species is placed in this context.

Forest genetic resource conservation of noble hardwoods in Spain

The main problems with the conservation of Noble Hardwood species are the following: selective cutting of the best trees, utilization of fruit-variety seeds in forest plantations, genetic introgression of cultivated varieties in wild populations. Priorities for establishing a conservation strategy are: the demarcation of provenance regions, the establishment of recomendations for the use of reproduction material, together with a fostering of planting efforts. The advantages and disadvantages of the in situ and ex situ conservation methods are listed for the species under consideration. Ex situ conservation is recommended for areas with populations whose variability has been reduced or in areas where the improvement of reproduction material is of interest.

The Conservation of Forest Genetic Resources: Case Histories from Canada, Mexico, and the United States

Abstract Genetic diversity in forest trees is best conserved in native populations. However, natural populations are threatened by many factors, eliminating valuable but often cryptic genetic resources. Gene banks (seed banks, plantations, or clonal archives) provide a prudent backup for breeders and ecological restorers should native populations be lost. Ottawa Valley white spruce, Guadalupe Island pine, and Torrey pine are examples of the value of gene banks in the conservation of forest genetic resources.

Biotechnology and the conservation of forest genetic resources: in vitro strategies and cryopreservation

In vitro techniques have a clear role within ex situ conservation strategies for trees and crop genetic resources, particularly where it is important to conserve specific genotypes or where normal propagules such as recalcitrant seed may not be suitable for long-term storage. These involve the use of conventional micropropagation, restricted growth techniques and cryopreservation. Although these techniques have been used primarily with herbaceous species, increasing attention is being given to woody species. Cryopreservation techniques for both woody and herbaceous species and new approaches which do not require freeze-induced cell dehydration, referred to as the ‘encapsulation-dehydration’ and the ‘vitrification’ techniques are described. Illustrative data are presented for the cryopreservation of willow using the encapsulation-dehydration technique.

The economics of biosphere reserves and the conservation of forest genetic resources

The economic evaluation of the gene bank component of a biosphere reserve project is one of the requirements before deciding to preserve an area. The direct and measurable benefits, together with the unmeasurable benefits, have to be weighted against the cost of the best forgone development alternative to determine if the preservation project is to be implemented. The safe minimum standard of conservation criterion is discussed. The decision is made in the midst of great uncertainties and possible irreversibilities. A conservative policy allowing maximum flexibility in the future and a close monitoring of the project is recommended.