Ex situ conservation of plant germplasm using biotechnology

Conservation of plant genetic resources attracts more and more public interest as the only way to guarantee adequate food supplies for future human generations. However, the conservation and subsequent use of such resources are complicated by cultural, economical, technical and political issues. Over the last 30 years, there have been significant increases in the number of plant collections and in accessions in ex situ storage centres throughout the World. The present review is of these ex situ collections and the contribution biotechnology has made and can make to conservation of plant germplasm. The applications and limitations of the new, molecular approaches to germplasm characterization are discussed. In vitro slow growth is used routinely for conserving germplasm of plants such as banana, plantain, cassava and potato. More recently, cryopreservation procedures have become more accessible for long-term storage. New cryopreservation techniques, such as encapsulation-dehydration, vitrification and desiccation, lengthen the list of plant species that can not only tolerate low temperatures but also give normal growth on recovery. Extensive research is still needed if these techniques are to be fully exploited.V.M. Villalobos is with the Food and Agriculture Organization of the United Nations, Viale delle Terme di Caracalia, 00100 Rome, Italy. F. Engelmann is with the International Plant Genetic Resources Institute (IPGRI), Via delle Sette Chiese 142, 00145 Rome, Italy.     

Biodiversity conservation and conservation biotechnology tools

This special issue is dedicated to the in vitro tools and methods used to conserve the genetic diversity of rare and threatened plant species from around the world. Species that are on the brink of extinction because of the rapid loss of genetic diversity and habitat come mainly from resource-poor areas of the world and from global biodiversity hotspots and island countries. These species are unique because they are endemic, and only a few small populations or sometimes only a few individuals remain in the wild. Therefore, the challenges to support conservation by in vitro measures are many and varied. The editors of this invited issue solicited papers from experts from Asia, Africa, Europe, Australia, and North and South America. This compilation of articles describes the efforts in these diverse regions toward saving plants from extinction, and details the direct application of in vitro and cryopreservation methods. In addition, these contributions provide guidance on propagation of rare plants, including techniques for large-scale propagation, storage, and reintroduction. The in vitro techniques for conserving plant biodiversity include shoot apical or axillary-meristem-based micropropagation, somatic embryogenesis, cell culture technologies and embryo rescue techniques, as well as a range of in vitro cold storage and cryopreservation protocols, and they are discussed in depth in this issue.     

水龙骨科植物的引种及种质资源保存

通过对５０种水龙骨科（Ｐｏｌｙｐｏｄｉａｃｅａｅ）植物的引种栽培,研究了水龙骨科植物的引种方法、栽培管理措施和繁殖技术,初步应用离体保存技术保存了１０种水龙骨科植物,并对主要类群做了应用及观赏性状评价。     

In vitro conservation of Dendrobium germplasm

Dendrobium is a large genus in the family Orchidaceae that exhibits vast diversity in floral characteristics, which is of considerable importance to orchid breeders, biotechnologists and collectors. Native species have high value as a result of their medicinal properties, while their hybrids are important as ornamental commodities, either as cut flowers or potted plants and are thus veritable industrial crops. Thus, preservation of Dendrobium germplasm is valuable for species conservation, breeding programs and the floriculture industry. Cryopreservation represents the only safe, efficient and cost-effective long-term storage option to facilitate the conservation of genetic resources of plant species. This review highlights 16 years of literature related to the preservation of Dendrobium germplasm and comprises the most comprehensive assessment of thorough studies performed to date, which shows reliable and reproducible results. Air-drying, encapsulation–dehydration, encapsulation–vitrification, vitrification and droplet-vitrification are the current cryopreservation methodologies that have been used to cryopreserve Dendrobium germplasm. Mature seeds, pollen, protoplasts, shoot primordia, protocorms and somatic embryos or protocorm-like bodies (PLBs) have been cryopreserved with different levels of success. Encapsulation–vitrification and encapsulation–dehydration are the most used protocol, while PLBs represent the main explant explored.     

Assessing conservation values: biodiversity and endemicity in tropical land use systems

Despite an increasing amount of data on the effects of tropical land use on continental forest fauna and flora, it is debatable whether the choice of the indicator variables allows for a proper evaluation of the role of modified habitats in mitigating the global biodiversity crisis. While many single-taxon studies have highlighted that species with narrow geographic ranges especially suffer from habitat modification, there is no multi-taxa study available which consistently focuses on geographic range composition of the studied indicator groups. We compiled geographic range data for 180 bird, 119 butterfly, 204 tree and 219 understorey plant species sampled along a gradient of habitat modification ranging from near-primary forest through young secondary forest and agroforestry systems to annual crops in the southwestern lowlands of Cameroon. We found very similar patterns of declining species richness with increasing habitat modification between taxon-specific groups of similar geographic range categories. At the 8 km(2) spatial level, estimated richness of endemic species declined in all groups by 21% (birds) to 91% (trees) from forests to annual crops, while estimated richness of widespread species increased by +101% (trees) to +275% (understorey plants), or remained stable (-2%, butterflies). Even traditional agroforestry systems lost estimated endemic species richness by -18% (birds) to -90% (understorey plants). Endemic species richness of one taxon explained between 37% and 57% of others (positive correlations) and taxon-specific richness in widespread species explained up to 76% of variation in richness of endemic species (negative correlations). The key implication of this study is that the range size aspect is fundamental in assessments of conservation value via species inventory data from modified habitats. The study also suggests that even ecologically friendly agricultural matrices may be of much lower value for tropical conservation than indicated by mere biodiversity value.     

世界特种油料种质资源保存概况

为加强特种油料种质资源的收集保存,更好地为育种研究利用提供服务,本文阐述了特种油料种质资源在我国及世界上重点国家的保存情况.美国、印度、欧盟、中国等13个国家共保存向日葵、红花、亚麻(含纤用)、蓖麻及苏子等特种油料种质资源约9万份,其中亚麻30000多份,向日葵21800多份,红花15000多份,蓖麻约5000多份,苏子近900份.欧盟、美国、俄罗斯和加拿大是亚麻资源的主要保存国家(地区);向日葵资源主要集中在美国、欧盟和中国;红花种质主要分布在印度、美国、中国和俄罗斯;蓖麻种质以中国、美国和印度居多.比较这些国家所拥有的特种油料种质资源数量,美国位居第一,保存数量最多,超过22000份;印度其次;欧盟、中国和俄罗斯居中.中国保存特油作物种质资源(蓖麻、向日葵、红花、苏子)8400余份,其中21%为国外种质,国内种质主要来源于湖北省、华北、东北、西北和西南地区.本文为我国特种油料种质资源的引进、收集保存提出了建议.     

The changing nature of collaboration in tropical ecology and conservation

Collaboration can improve conservation initiatives through increases in article impact and by building scientific understating required for conservation practice. We investigated temporal trends in collaboration in the tropical ecology and conservation literature by examining patterns of authorship for 2271 articles published from 2000 to 2016 in Biotropica and the Journal of Tropical Ecology. Consistent with trends in other studies and scientific disciplines, we found that the number of authors per article increased from 2.6 in 2000 to 4.2 in 2015 using a generalized linear model (glm). We modeled changes in multinational collaboration in articles using a glm and found that the mean number of author‐affiliated countries increased from 1.3 (±0.6 SD) to 1.7 (±0.8 SD) over time and that increases were best explained by the number of authors per article. The proportion of authors based in tropical countries increased, but the probability of tropical–extratropical collaboration did not and was best explained solely by the number of authors per article. Overall, our analyses suggest that only certain types of collaboration are increasing and that these increases coincide with a general increase in the number of authors per article. Such changes in author numbers and collaboration could be the result of increased data sharing, changes in the scope of research questions, changes in authorship criteria, or scientific migration. We encourage tropical conservation scientists continue to build collaborative ties, particularly with researchers based in underrepresented tropical countries, to ensure that tropical ecology and conservation remains inclusive and effective.     

长江流域林木资源的重要性及种质资源保护

中国长江流域有着丰富的林木资源, 包含极高水平的物种多样性、特有性和遗传多样性。根据考古证据, 在旧石器和新石器时代长江文明早期的孕育与发展中, 林木在食物、能源、工具、建筑和舟船中的应用起到了关键作用。现在, 长江流域和珠江流域逐渐成为国内木材供给的热点地区。面对木材供给总量不足和大径级木材结构性短缺问题, 长江流域林木资源将是未来国内木材安全的重要保障。这使得林木种质资源的保护更加迫切。针对长江流域林木种质资源保护存在的家底不清和保存体系不完善问题, 我们应尽快完成林木种质资源的全面调查和重要树种的多样性分析; 完善原地、异地和设施保存相结合的保存体系。     

短叶省藤种质离体培养保存研究

本文对短叶省藤种质的离体培养保存进行了探索性研究。结果表明：种质以丛芽形式,采用ＲＥＯ保存培养基,在温度１２．５℃和光照３００１Ｘ×１２ｈ／ｄ的保存条件下,可安全保存１８个月以上,保存率＞２５％,丛芽平均高生长小于２．２ｃｍ。种质保存一年后,转接至增殖或生根培养基,仍可诱导增殖和生根．结果表明离体保存具一定可行性,其保存模式可预定为：增殖培养２个月＋离体保存１８个月的循环模式．     

Applied microbiology and biotechnology in the conservation of stone cultural heritage materials

The contribution of applied microbiology and biotechnology for the preservation and restoration of culturally relevant stoneworks has been used only to a minor extent. Until recently it only involved the identification of the living organisms accountable for the deterioration of those materials by classic phenotypic identification methods. This seems to be changing, given the amount of work recently published that focuses in the introduction of molecular-based techniques for the detection of microorganisms in historic stone. Such techniques complement and expand the information up till now gathered by conventional identification methods. Along with this, efforts are being made to develop and implement bio-based methodologies that may actively contribute to the bioremediation of weathered historic stoneworks. The present mini-review aims to provide an overview of recent findings on these matters.     

滇南热带植物物种多样性的迁地保护

本文论述了滇南热带植物多样性迁地保护区的建设与稀有濒危植物的保护。进行了种子贮藏与萌发、幼苗生长条件和不同栽培条件等试验以及生物学特性观察等。雨季成熟的大粒型种子一般不耐贮藏,中、小粒型种子较耐贮藏,细小种子耐贮藏。育苗中幼苗除强阳性树种不需遮荫外,大多数热带雨林树种幼苗和幼树期都需要一定的荫蔽条件才能生长良好。西双版纳热带植物的发芽、抽梢、开花高峰期都集中在日平均温达20℃左右的3月。大量开始落叶是在1～2月,3月为多数植物的落叶盛期。果实在干凉季（11～2月）成熟的占23.9％,干热季（3～5月）成熟的占36.4％,湿热季（6～10月）成熟的占40％。     

Nitrogen conservation in a tropical rain forest

Summary A series of plots in an Amazonian Rain Forest were trenched and treated with calcium to determine the effects of perturbation on numbers and activity of nitrifying bacteria. Although treatment resulted in between 2 and 26% of the nitrogen being lost from the humus layer, virtually all of it was in the NH ₄ ⁺ form. Numbers of nitrifying bacteria in the plots were relatively low. The low numbers and low activity of nitrifying bacteria is attributed to the low pH and high concentration of tannins in the root mat. It is hypothesized that the suppression of nitrifying bacteria results in nitrogen conservation in the rain forest.     

The use of willingness-to-pay approaches in mammal conservation

With limited monetary resources available for nature conservation, policy‐makers need to be able to prioritize conservation objectives. This has traditionally been done using qualitative ecological criteria. However, since declines in species and habitats are largely the result of socio‐economic and political forces, human preferences and values should also be taken into account. An environmental economics technique, contingent valuation, provides one way of doing this by quantifying public willingness‐to‐pay towards specific conservation objectives. In this paper, the use of this approach for quantifying public preferences towards the UK Biodiversity Action Plans for four different British mammal species is considered. The species included are the Red Squirrel Sciurus vulgaris, the Brown Hare Lepus europaeus, the Otter Lutra lutra and the Water Vole Arvicola terrestris. Willingness‐to‐pay for conservation was increased by the inclusion of the Otter among the species, membership of an environmental organization and awareness of the general and species‐specific threats facing British mammals. It was reduced by the presence of the Brown Hare among the species being considered. These findings for British mammals are compared with other willingness‐to‐pay studies for mammal conservation worldwide. Willingness‐to‐pay tends to be greater for marine mammals than terrestrial ones, and recreational users of species (tourists or hunters) are generally more willing than residents to pay towards species conservation. The choice of technique for eliciting willingness‐to‐pay from respondents is also shown to be highly significant. Willingness‐to‐pay values for British mammals derived from contingent valuation are sensitive to the species included rather than merely symbolic. This indicates that, with care, such measures can be used as a reliable means of quantifying public preferences for conservation, and therefore contributing to the decision‐making process. However, irrespective of the internal consistency of contingent valuation, the validity of the approach, especially for use in nature conservation, is disputed. Willingness‐to‐pay is likely to reflect many interrelated factors such as ethical and moral values, knowledge and tradition, and monetary values may not be an adequate representation of these broader considerations. Willingness‐to‐pay approaches should therefore be used in addition to, rather than in place of, expert judgements and more deliberative approaches towards policy decision‐making for conservation.