The leaves of the common box,Buxus sempervirens (Buxaceae), become red as the level of a red carotenoid,anhydroeschscholtzxanthin, increases

Carotenoids from the leaves of the common box,Buxus sempervirens (Buxaceae), which turn red in late autumn to winter, were analyzed by reversed-phase HPLC. A novel carotenoid, monoanhydroeschscholtzxanthin (3), was isolated from the red-colored leaves. UV-VIS, MS,¹H-NMR and CD spectral data showed that the structure of 3 was (3S)-2′, 3′, 4′, 5′-tetradehydro-4, 5′-retro-β, β-caroten-3-ol. As well as anhydroeschscholtzxanthin (2), the major red carotenoid in the leaves, eschscholtzxanthin (4) was identified. Very small amounts of yellow carotenoids (neoxanthin, violaxanthin, lutein and β-carotene), which are major components of green leaves, were present in the red-colored leaves. The amounts of chlorophylla andb in the leaves decreased markedly during coloration, even at the early stages, whereas those of the yellow carotenoids decreased gradually. In contrast, the content of 2, a red carotenoid, increased steadily during coloration. The biosynthetic pathway of 2 inB. sempervirens was deduced tentatively on the basis of the individual carotenoid contents during autumnal coloration.     

Spread of plant pathogens and insect vectors at the northern range margin of cypress in Italy

The Mediterranean cypress (Cupressus sempervirens) is a multi-purpose tree widely used in the Mediterranean region. An anthropogenic range expansion of cypress has taken place at the northern margin of the range in Italy in recent decades, driven by ornamental planting in spite of climatic constraints imposed by low winter temperature. The expansion has created new habitats for pathogens and pests, which strongly limit tree survival in the historical (core) part of the range. Based on the enemy release hypothesis, we predicted that damage should be lower in the expansion area. By comparing tree and seed cone damage by pathogens and pests in core and expansion areas of Trentino, a district in the southern Alps, we showed that tree damage was significantly higher in the core area. Seed cones of C. sempervirens are intensively colonized by an aggressive and specific pathogen (the canker fungus Seiridium cardinale, Coelomycetes), associated with seed insect vectors Megastigmus wachtli (Hymenoptera Torymidae) and Orsillus maculatus (Heteroptera Lygaeidae). In contrast, we observed lower tree damage in the expansion area, where a non-aggressive fungus (Pestalotiopsis funerea, Coelomycetes) was more frequently associated with the same insect vectors. Our results indicate that both insect species have a great potential to reach the range margin, representing a continuous threat of the arrival of fungal pathogens to trees planted at extreme sites. Global warming may accelerate this process since both insects and fungi profit from increased temperature. In the future, cypress planted at the range margin may then face similar pest and pathogen threats as in the historical range.     

The contribution of common and rare species to plant species richness patterns: the effect of habitat type and size of sampling unit

Understanding how overall patterns of spatial variation in species richness are affected by distributional patterns of species has been an area of growing concern. In the present study, we investigated the relative importance of common and rare species as contributors in overall plant species richness. We further examined if the effects of common or rare species in richness patterns are affected by the size of the sampling units and if the observed patterns hold at different habitats. We used a dataset of 5,148 higher plant species distributed across 16,114 sampling plots located in 240 sites of the NATURA 2000 network of Greece. We ranked all species based on the number of sites they occupied and we developed a common to rare and a rare to common sequence. We correlated those sequences with cumulative species distributions. We performed this analysis in nine different sizes of sampling units and in three different datasets referring to (a) all habitat types together, (b) coniferous habitats only and (c) alpine habitats only. Our analysis showed that despite the proportionally higher numbers of restricted species, widespread species make a greater contribution to overall richness patterns and that this observed pattern does not depend on the size of the sampling units. Moreover, the observed pattern stands for different habitat types. Our findings support the generality of this pattern and highlight the importance of widespread species as adequate indicators of biodiversity patterns at various habitat types. Electronic supplementary material  The online version of this article (doi:) contains supplementary material, which is available to authorized users.     

In vitro micropropagation of Primula scotica: a rare Scottish plant

A simple micropropagation method is reported for Primula scotica, a rare plant, endemic to the North of Scotland. The technique involves the clonal proliferation of seed-derived plantlets on either hormone free tissue culture medium or on medium containing benzyl amino purine and indole acetic acid. Average multiplication rates of 4–6 were obtained for plants grown on plant growth regulator supplemented medium. The micropropagation method was applied to four different clones of P. scotica and clonal differences were observed in relation to media type. Some plants from certain clones did display hyperhydricity, however, this was circumvented by using frequent sub-culturing intervals and transferring the plants to hormone-free medium. Plantlets rooted on both media types and displayed normal, true-to-type rosette morphology. The cultures did not callus and development proceeded via shoot and root production only. The in vitro-grown plants could be transferred to ex vitro conditions and a range of growth substrates were assessed for their efficacy in supporting ex vitro growth, with a view to developing longer-term strategies for the transfer and reintroduction of micropropagated P. scotica plants into natural habitats. The simple method described in this paper may offer the potential of being applied to other endangered Primula spp.     

珍稀濒危植物紫荆木生态学研究进展

珍稀濒危植物作为生物多样性的重要组成部分,是保护生物学研究的核心内容之一。紫荆木(Madhuca pasquieri)为现状稀有种,IUCN名录中濒危等级为VU易危,在中国被列为国家重点保护野生植物(Ⅱ级)和极小种群野生植物,是稀有的油料树种和珍贵的用材树种,具有极高的药用价值。在全球气候变化和生境破碎化的大背景下,紫荆木的现状研究和保护策略的制定显得尤为重要。该文介绍了紫荆木自然地理分布、群落生态学特征,归纳总结了国内外的保护应用及研究现状。目前针对紫荆木就地保护、迁地保护、化学成分、人工培育技术等方面已开展了一些研究工作,但研究仍处于初级阶段。下一步可完善紫荆木分布信息,并结合野外调查和长期实验,系统研究其生物及生态学特性。同时,将就地保护、迁地保护和回归有机结合,应用分子生物学技术加强紫荆木育种、繁殖和栽培技术的研究,建立繁殖培育基地,并积极开发其经济价值,在园林绿化中推广应用。     

The reaction of some sand-dune plant species to experimentally imposed environmental change: a reductionist approach to stability

Coastal dunes in western Europe have long been under grazing and recreational pressure, but the vegetative cover appears to be remarkably resilient. In a series of experiments on Ynyslas Dunes, Cardigan Bay (Wales, U.K.), trampling, protection, fertiliser, and herbicide treatments were monitored using non-destructive and destructive sampling methods. This paper discusses the behaviour of 12 important species after these treatments on three major dune habitats: Agrostis tenuis, Ammophila arenaria, Bellis perennis, Festuca rubra, Galium verum, Leontodon taraxacoides, Ononis repens, Plantago lanceolata, Poa subcaerulea, Thymus praecox, Homalothecium lutescens, Tortula ruraliformis.Although stability is usually thought of as a feature of the community, a reductionist approach suggests that grasses react quickly but temporarily, dicotyledonous forbs often show slower reaction times, each species reacting in its own way to changes in the environment. A tentative classification of our study species is possible.Nomenclature follows Smith (1978), for bryophytes and Clapam, Tutin & Warburg (1962), for angiosperms.     

Ladybird population dynamics in potato: comparison of native species with an invasive species, Harmonia axyridis

Following the detection of the harlequin ladybird, Harmonia axyridis, in 2003 in potato crops in Belgium, a study was carried out between 2004 and 2006 on the phenology of this species compared to native species in potato. The results confirmed the success of H. axyridis, with high population levels in 2004 and 2005. In 2006, aphid populations were very low and no H. axyridis larvae were sampled in potato, but the indigenous species Coccinella septempunctata and Propylea quatuordecimpunctata were detected. A species by species comparison of the date of first larvae detection, the larvae population peak, and the difference between this peak and the aphid population peak was performed. Results showed a clear correlation between C. septempunctata and P. quatuordecimpunctata and potato aphids, with a delay of 3.5 and 6.5 days between the aphid and ladybird population peaks for the two native species. H. axyridis arrived 7–8 days after the two indigenous species and the larval peak population occurred 15.8 days after the aphid population peak. This meant that H. axyridis had to complete its larval development with very low aphid populations or even with no aphids at all. The reason for its late arrival and the possible food resources used by H. axyridis larvae are discussed.     

Castilleja chambersii (Scrophulariaceae), a new rare species from the northern Coast Range of Oregon

Castilleja chambersii is described from several collections made in the Coast Range of southwestern Clatsop County, Oregon. The new species is a member of subgenusCastilleja and is most closely related toC. parviflora andC. rupicola. This rare species is known from only three small and geographically restricted populations. Two new meiotic chromosome counts ofn=12 are reported for the new species.     

Competition in microcosm between a clonal plant species (Bolboschoenusmaritimus) and a rare quillwort (Isoetessetacea) from Mediterranean temporary pools of southern France

Bolboschoenus maritimus, a clonal species, is locally invasive in Mediterranean temporary pools where it threatens endangered rare plant species such as Isoetes setacea. The combination of management modifications (grazing) and of the progressive accumulation of fine sediments in the pools contributed to the establishment of competitive perennial plants such as B. maritimus. The competitive advantage of B. maritimus on I. setacea has been studied in controlled conditions. The goal of this experiment was to assess the role of environmental conditions in the output of the competition between Bolboschoenus and Isoetes, notably hydrology and soil richness. For this purpose, Isoetes was cultivated alone (three individuals/pot) and with Bolboschoenus (three individuals of both species). The experiment was run with five replicates on six types of sediment (gradient of richness in sand/silt/clay) combined with three hydrological treatments (flooded, wet. and dry). The competitive advantage of Bolboschoenus was measured as the ratio of the production of Isoetes in mixture versus monoculture. The results showed that Isoetes was always outcompeted by Bolboschoenus. However, the competitive advantage of Bolboschoenus on Isoetes, was more related to hydrology than to soil richness. The competitive advantage of Bolboschoenus was very high in wet and flooded conditions and very low in dry conditions. This situation may lead to the extinction, medium-term, of the populations of I. setacea. The introduction of ovine grazing or of cut back practices in temporary pools could reduce the B. maritimus biomass and help toward the conservation of I. setacea populations. Guest editors: B. Oertli, R. Cereghino, A. Hull & R. Miracle Pond Conservation: From Science to Practice. 3rd Conference of the European Pond Conservation Network, Valencia, Spain, 14–16 May 2008     

Inheritance of isozymes in Brassica campestris L. and genetic divergence among different species of Brassiceae

Electrophoretic investigations of Brassica campestris revealed 8 polymorphic loci that had not been described earlier. The inheritance of 7 of them was determined by crosses between different accessions of B. campestris. A phylogeny of B. campestris, B. nigra, B. alboglabra, Sinapis arvensis and S. alba was estimated from the analysis of 15 isozyme loci. The phylogeny showed a close relationship between B. nigra and S. arvensis and a less close relationship between B. campestris and B. oleracea. S. alba was remotely-related to all of the other species.     

Corylomyces: a new genus of Sordariales from plant debris in France

The new genus Corylomyces, isolated from the surface of a hazelnut (Corylus avellana) in the French Pyrenees, is described, illustrated and compared with morphologically similar taxa. It is characterised by tomentose, ostiolate ascomata possessing long necks composed of erect to sinuose hairs, and one- or two-celled, opaque, lunate to reniform ascospores. Analyses of the SSU and LSU fragments rDNA gene sequences support its placement in the Lasiosphaeriaceae (Sordariales).     

An integrative approach to species delimitation in Echinodorus (Alismataceae) and the description of two new species

Summary  Taxonomy of the genus Echinodorus is partially revisited in the light of current understanding of the phylogenetic relationships of the genus. As a result of new taxonomy, the species status of some previously synonymised taxa are restored, other names are synonymised, and some nomenclatural problems unnoticed by previous authors are resolved. Two new species, Echinodorus reptilis and E. emersus are described. The subgeneric divisions of the genus are not accepted, and all subspecific taxa are either rejected or established as species. As a result, 28 species based on a phylogenetic species concept are now recognised in Echinodorus and an identification key to these species is provided.     

Regeneration of plants from alginate-encapsulated shoot tips of Withania somnifera (L.) Dunal, a medicinally important plant species

A protocol was developed for plant regeneration from encapsulated shoot tips collected from in vitro proliferated shoots of Withania somnifera. The best gel composition was achieved using 3% sodium alginate and 75 mM CaCl2.2H2O. The maximum percentage response (87%) for conversion of encapsulated shoot tips into plantlets was achieved on MS medium supplemented with 0.5 mg/l IBA after 5 weeks of culture. The conversion of encapsulated shoot tips into plantlets also occurred when calcium alginate beads having entrapped propagules were directly sown in autoclaved soilrite moistened with 14-MS salts.     

垫状植物囊种草对群落物种多样性的影响

在甘肃盐池湾国家级自然保护区内海拔4137 m处,选择典型的囊种草垫状植被设置研究样地,研究了垫状植物囊种草对群落物种组成和群落物种多样性的影响,并且定量的研究了囊种草对群落物种丰富度的影响能力和维持潜力。研究结果表明:囊种草为群落中增加了新的植物种类,并且提高了部分生境一般种的多度;囊种草的出现提高了群落物种密度和物种丰富度,进而提高了群落物种多样性;囊种草斑块的增加将会引起景观水平物种丰富度的增加,表明囊种草具有为群落中引入新的植物种类进而提高群落物种丰富度的能力;在景观水平,囊种草所创造的生境多样性则成为一种保障,可以维持景观中物种丰富度从而降低物种损失的风险,表明囊种草具有较高的群落物种丰富度维持潜力。     

Physiological responses of Uroleucon jaceae (L.) to seasonal changes in the quality of its host plant Centaurea jacea L.: multilevel control of adaptations to the life cycle of the host

Summary Exploiters of short-lived plants have evolved strategies in response to physiological changes that occur during the development of their hosts. The ability to adapt to host quality changes is necessary particularly if the mobility of an animal is poor or risk-constrained. In the plant-aphid system Centaurea jaceae-Uroleucon jaceae, the responses of the aphid to the seasonal changes in its host plant grown in poor and good quality soil were investigated. Coarse- and fine-tuned physiological reactions were observed in discrete aphid generations which were reared on plants grown either in a growth chamber or in a greenhouse. The number of ovarioles and developmental time depended on extrinsic factors (length of photoperiod) not directly related to plant quality. The reproductive investment of the aphids was also independent of their total dry weight. However, within the gonadal system high correlations were found at the embryonic level (e.g. the number of sclerotized embryos or the length of the oldest embryos per ovariole were highly correlated with gonadal dry weight). Aphids which were living on the 4-leaf stage of high-quality host plants showed a significantly higher investment in their gonads than aphids feeding on senescenting hosts. Factor analysis corroborated that aphids reared on poor-quality hosts revealed no grouping of variables measured, whereas those which were reared on high-quality plants showed clustering in respect of somatic (tibia length, dry weight of soma) and gonadal (number of sclerotized and unsclerotized embryos, length of the oldest embryos, ovariole number, gonad dry weight) factors. Three different levels of adaptive response to plant quality are distinguished: individual response to host quality, maternal influences on offspring and response to changes not specific to habitat (photoperiod). These different levels of regulation are thought to enable the aphids to adapt to a host of a given nutritional quality and anticipate deteriorating habitat quality simultaneously. It is concluded that physiological constraints in aphids are only revealed when aphids are exposed to severe nutritional stress for several generations.     

Rhipicephalus appendiculatus and R. zambeziensis (Acari: Ixodidae) from Zambia: a molecular reassessment of their species status and identification

The closely related species Rhipicephalus appendiculatus and R. zambeziensis co-occur in a wide area in Zambia. In this area, specimens of both species have been collected on the same individual host at the same time. In addition, specimens that are morphologically intermediate between R. appendiculatus and R. zambeziensis have been found in this area. These observations cast some doubt on the species status of R. appendiculatus and R. zambeziensis. Because the two taxa have varied influences on the epidemiology of East Coast fever (ECF), a cattle disease for which they act as vectors, it is essential that their taxonomic status is clarified and their identification is accurate. Therefore a phylogenetic analysis of nucleotide sequences of the ITS2 and a fragment of the mitochondrial 12S rDNA was performed to reassess the specific status of both taxa. This revealed two well supported clades coinciding with R. appendiculatus and R. zambeziensis as two separate species. In order to facilitate species identification a PCR-RFLP diagnostic assay was developed based on BauI digestion of the ITS2 gene. This assay produced clear diagnostic banding patterns for the two species and is applicable over a wide range of both species’ distribution. Nucleotide sequence data reported in this paper are available in the GenBank™ under the accession numbers DQ849203–DQ849274.     

Novel observations of midge and mosquito larval population dynamics in leaves of the northern pitcher plant,Sarracenia purpurea L.

The invertebrate communities in Sarracenia purpurea were characterized by surveying the contents of 474 leaves from six pitcher plant populations in the eastern United States. More than 8200 invertebrate specimens, both living and dead, were recovered. Midge and mosquito larvae comprised 7907 (96%) of the specimens, with a mean of 16.9 dipteran larvae per leaf. Although midge larvae were present at all collection sites, mosquito larvae were absent from two of the sites. In the latter sites, the number of midge larvae per leaf was greater. This report documents for the first time that there is no statistical difference between the average number of Diptera larvae per leaf for sites that contain both midge and mosquito larvae compared to sites that contain only midge larvae. It appears that pitcher plants maintain an average number of larvae per leaf based on a number of interacting factors which we do not fully understand. This investigation documents that in the absence of mosquito larvae, more midge larvae are found per leaf per leaf than would be predicted based on data from sites that contain both larval taxa.     

The borderlands and possible hybrids between three species of macaques,M. nigra,M. nigrescens,andM. hecki,in the northern peninsula of Sulawesi

The borderlands between three species of macaques,Macaca nigra, M. nigrescens, andM. hecki, which live on the northern peninsula of Sulawesi were surveyed mainly via observations of pet monkeys kept by local people. The borderlands between these species could be delineated. Some monkeys of peculiar appearance and/or with mixtures of the external characteristics of two species were found in the borderlands between the respective pairs of species. However, such possibly hybrid monkeys were seen or originated only in the very limited areas where the species might come into contact with each other.