Six new species ofAcourtia (Asteraceae) and a historical account ofAcourtia mexicana

Six Mexican species ofAcourtia are described. One of these novelties seems to be related toAcourtia mexicana (Lag. ex D. Don) H. Rob., whose nomenclature has been misunderstood for decades; an exhaustive literature review and examination of herbarium material supports Robinson’s combination.

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Resumen  Se describen seis nuevas especies mexicanas deAcourtia. Una de estas novedades parece estar relacionada conAcourtia mexicana (Lag. ex D. Don) H. Robinson, especie cuya nomenclatura ha sido mal interpretada por décadas; una exhaustiva revisión de la literatura así como de material de herbario, apoyan la combinación de Robinson.

     

Ecology of Hippophae salicifolia D. Don of temperate and sub-alpine forests of North Sikkim Himalayas—a case study

Hippophae salicifolia D. Don or Sea buckthorn is one species that has great potential for improving ecological and economic developments in the mountain areas of North Sikkim. The plant is found naturally at altitudes ranging from 2,377 to 3,093 m. in riverine (river side or torrential side) and non-riverine (non river or non torrential side) areas where geo-physico-chemical parameters like aerial temperature, aerial moisture, soil pH, soil temperature, and soil moisture varied significantly. We analyzed ecological parameters and species association using standard quadrates. Actinorhizal plants invade nitrogen-poor soils because of their ability to form root nodule symbioses with N₂-fixing actinomycetes known as Frankia. Variation in nodulation with respect to plant height was also observed. This was higher in riverine areas compared to non riverine sites at higher altitudes.     

Blarinoides aliciae sp. nov., a new Soricidae (Mammalia,Lipotyphla) from the Pliocene of Spain

A new species of Blarinoides (Soricidae, Mammalia), Blarinoides aliciae, is described from the Pliocene of Tollo de Chiclana (Guadix Basin, southeastern Spain). It is notably smaller than the single species of this genus known until now, B. mariae. B. aliciae is recorded from several other Spanish localities, but the sample from Tollo de Chiclana-3 is the most numerous. B. aliciae proves the simultaneous existence of two different species of Blarinoides in Europe during the Pliocene: one of large size in central and eastern Europe, and another one of small size in Iberia.     

Apocricetus barrierei (Rodentia,Mammalia) from La Bullana 2B and La Bullana 3 (Cabriel Basin,Valencia, Spain). Revision of the Late Miocene–Early Pliocene forms of the genus Apocricetus

Apocricetus Freudenthal et al. (Treballs del Museu de Geologia de Barcelona 7: 11–93, 1998) is a medium to large Cricetinae, practically without mesolophids in the m1 and m2, with long third molars; anterior and posterior protolophule are present and the posterior metalophule is reduced or absent. Apocricetus barrierei (Mein and Michaux Comptes Rendus Academie de Sciences de Paris D 270: 2780–2783, 1970) was defined on the basis of three specimens from the French locality Chabrier. Apart from this site, several French and Spanish localities of Early Pliocene age contain remains of this species. Despite this extra material, the species is poorly characterized, and none of the localities contains material of all six dental elements. In this paper, two new assemblages from La Bullana 2B and La Bullana 3 (Cabriel Basin, Spain) are described. The rich assemblage from La Bullana 2B provides a better insight in the metrical and morphological variability of this species.     

Always being well prepared for defense: The production of deterrents by juvenile Chrysomelina beetles (Chrysomelidae)

In response to herbivores, plants produce a variety of natural compounds. Many beetle species have developed ingenious strategies to cope with these substances, including colonizing habitats not attractive for other organisms. Leaf beetle larvae of the subtribe Chrysomelina, for example, sequester plant-derived compounds and use them for their own defense against predators. Using systematically modified structural mimics of plant-derived glucosides, we demonstrated that all tested Chrysomelina larvae channel compounds from the gut lumen into the defensive glands, where they serve as intermediates in the synthesis of deterrents. Detailed studies of the sequestration process revealed a functional network of transport processes guiding phytochemicals through the larval body. The initial uptake by the larvae’s intestine seems to be fairly unspecific, which contrasts sharply with the specific import of precursors into the defensive glands. The Malpighian tubules and hind-gut organs facilitate the rapid clearing of body fluid from excess or unusable compounds. The network exists in both sequestering species and species producing deterrents de novo. Transport proteins are also required for de novo synthesis to channel intermediates from the fat body to the defensive glands for further conversion. Thus, all the tools needed to exploit host plants’ chemistry by more derived Chrysomelina species are already developed by iridoid–de novo producers. Early intermediates from the iridoid–de novo synthesis which also can be sequestered are able to regulate the enzyme activity in the iridoid metabolism.     

The genus <Emphasis Type="Italic">Diaporthe</Emphasis>: a rich source of diverse and bioactive metabolites

The genus Diaporthe (asexual state: Phomopsis) comprises pathogenic, endophytic and saprobic species with both temperate and tropical distributions. Although species of Diaporthe have in the past chiefly been distinguished based on host association, studies have confirmed several taxa to have wide host ranges, suggesting that they move freely between hosts, frequently co-colonizing diseased or dead tissue, while some species are known to be host-specific. They are also very frequently isolated as endophytes of seed plants. Due to their importance as plant pathogens, the genus has been thoroughly investigated for secondary metabolites, including during screening programs aimed at the discovery of novel bioactive natural products, but the respective information has never been compiled. Therefore, we have examined the relevant literature to explore and highlight the major classes of metabolites of Diaporthe and their Phomopsis conidial states. These fungi predominantly produce a large number of polyketides, but cytochalasins and other types of commonly encountered fungal secondary metabolites are also predominant in some species. Interestingly, not a single metabolite which is also known from the host plant has ever been isolated as a major component from an endophytic Diaporthe strain, despite the fact that many of the recent studies were targeting endophytic fungi of medicinal plants.     

Composition of ichthyofauna of the upper Don basin

The characteristic of species composition of ichthyofauna of the upper Don basin, including data on moderate and small rivers, is provided for the first time. The examined part of the basin embraces territories of Tula, Ryazan, Lipetsk, Tambov, and Voronezh oblasts. A total of 51 species—66.7% of the total number of species recorded in water courses of the entire Don basin—were recorded in the ichthyofauna of the region. The decrease in the number of species in the upper Don basin as compared to its other sections proceeds mainly at the expense of marine and euryhaline species, as well as due to anadromous acipenserids. In this part of the basin, a smaller number of invading species was also recorded. However, Amur sleeper Perccottus glenii that was not discovered so far in other parts of the basin has dispersed here sufficiently widely. The wide distribution of bearded stone loach Barbatula barbatula and minnow Phoxinus phoxinus can be possibly also considered a distinguishing feature of fish population of the upper reaches of the Don in relation to other sites.     

Interspecific competition between alien and native congeneric species

A good way to check hypotheses explaining the invasion of ecosystems by exotic plants is to compare alien and native congeneric species. To test the hypothesis that invasive alien plants are more competitive than natives, we designed a replacement series experiment to evaluate interspecific competition between three Senecio species representing the same bushy life form: two alien species (S. inaequidens and S. pterophorus, both from South Africa) and a native species from the south-east of the Iberian Peninsula and Maghreb (S. malacitanus). While S. inaequidens is widespread throughout western Europe and is expanding towards the south of Spanish–French border, the geographical distribution of the recently introduced S. pterophorus is still limited to north-eastern Spain. Plants from each species were grown in pure and in mixed cultures with one of their congeners, and water availability was manipulated to evaluate the effects of water stress on competitive abilities. Our results show that the alien S. inaequidens is the most competitive species for all water conditions. The native S. malacitanus is more competitive that the alien S. pterophorus in water stress conditions, but this situation is reversed when water availability is not limiting.     

The intersection of conservation and horticulture: bird-pollinated Lotus species from the Canary Islands (Leguminosae)

This paper critically reviews the status of the ??lotus vines?? (Lotus section Rhyncholotus) in the wild and in cultivation. The literature concerning the conservation status of this group is scattered and in many places is not updated. Besides, the most recent efforts in conservation on this group have not been published in widely available sources and are mainly published in Spanish. Our aims in this paper are to compile the most recent information regarding the conservation status, studies on genetic diversity and the latest strategies for the conservation of this group. The four species are all critically endangered in the wild. Two species (Lotus berthelotii and L. maculatus) are widely cultivated in Europe and North America but the range of genotypes in cultivation is likely to be small, as the plants are propagated by cuttings. Hybrids between these two species are also in cultivation, and some have been patented. Commercial horticulture has considerable implications for overall conservation strategies, and these implications are discussed. We suggest that a circa situm conservation could improve the conservation strategies of these four species in the Canary Islands.     

Invasive Lespedeza cuneata and native Lespedeza virginica experience asymmetrical benefits from rhizobial symbionts

Background and Aims

Lespedeza cuneata (Dum. Cours.) G. Don is an invasive legume that displaces populations of native N. American congeners. Our aims are to determine the growth benefits of different rhizobacterial strains for L. cuneata and native Lespedeza virginica (L.) Britton, and to determine if these strains influence competition between these plants.

Methods

Plants were grown under nitrogen-limiting conditions in sterilized soil in pairs consisting of two L. cuneata, two L. virginica, or one of each species, and then plants were inoculated with one of seven rhizobial isolates, or with a no-strain control. After 3 months, plants were harvested for determination of biomass and nodulation rate.

Results

Five of the assayed stains improved L. cuneata biomass over uninoculated controls, but none of the strains benefited L. virginica. L. cuneata plants had more biomass and root nodules when grown in competition with L. virginica than with a conspecific.

Conclusions

Asymmetrical benefits from these symbionts accrued to invasive L. cuneata but not to native L. virginica, and this may provide the invader with a growth advantage in the field. Changes in the availability of effective symbionts in the soils of invaded sites can shape performance of native and invasive plants.     

Dermatological remedies in the traditional pharmacopoeia of Vulture-Alto Bradano, inland southern Italy

This study documents indigenous medicinal plant utilization, management and the threats affecting them. The study was carried out in Mana Angetu district between January 2003 and December 2004. Ethnobotanical data were collected using semi structured interviews, field observations, preference and direct matrix ranking with traditional medicine practitioners. The ethnomedicinal use of 230 plant species was documented in the study area. Most of the plants (78.7%) were reportedly used to treat human diseases. The most frequently used plant part were roots (33.9%), followed by leaves (25.6%). Most of the medicinal species (90.4%) were collected from the wild. Direct matrix analysis showed that Olea europaea L. Subsp. cuspidata (Wall. ex G. Don) was the most important species followed by Acacia tortilis (Forssk.) Hayne (120) indicating high utility value of these species for the local community. The principal threatening factors reported were deforestation (90%), agricultural expansion (85%) and fire (53%). Documenting the eroding plants and associated indigenous knowledge can be used as a basis for developing management plans for conservation and sustainable use of medicinal plants in the area.     

Beneficial endophytic microorganisms of Brassica – A review

Brassica species display enormous diversity and subsequently provide the widest assortment of products used by man from a single plant genus. Many species are important for agriculture, horticulture, in bioremediation, as medicines, soil conditioners, composting crops, and in the production of edible and industrial oils such as liquid fuels and lubricants. Many wild Brassica relatives possess a number of useful agronomic traits, including beneficial microbial endophytes that could be incorporated into breeding programs. Endophytes of Brassica, and/or their metabolites, have been demonstrated to improve and promote plant growth; increase yield; reduce disease symptoms caused by plant pathogens; reduce herbivory from insect pests; remove contaminants from soil; improve plant performance under extreme conditions of temperature and water availability; solubilise phosphate and contribute assimilable nitrogen to their hosts. Brassica napus (oilseed rape) and Brassica oleracea var. botrytis (broccoli and cauliflower) are the most economically important species of Brassica worldwide. These commercial crops are attacked by a wide range of pathogens and insect pests that are responsible for millions of dollars in lost revenue, with current control options offering little mitigation. No alternative control products are available for the Brassica industry, although it has been well documented in the literature that the use of endophytic microorganisms can offer beneficial traits to their host plants, including pest and disease resistance. The aim of this review is to describe the literature concerning beneficial microbial endophytes and their prospects to enhance or provide additional traits to their Brassica host species.     

Distribution and numbers of Ukrainian lamprey Eudontomyzon mariae (Petromyzontidae) in the upper Don basin

The characteristic of distribution of Ukrainian lamprey Eudontomyzon mariae in the upper Don basin is presented. The examined part of the basin covers territories of Kursk, Orel, Tula, Ryazan, Lipetsk, Tambov, and Voronezh oblasts. It is shown that, at the present time in the upper Don basin, restoration of the range and an increase in the numbers of Ukrainian lamprey is occurring. The main concentrations of the species were recorded in the Don and Krasivaya Mecha rivers and their tributaries. In the basin of the Sosna River—one of the largest tributaries of the Don—Ukrainian lamprey is very widely distributed, but its population remains small and rarified. To preserve the species in the upper Don basin, it is suggested—in addition to already existing specially protected natural territories—to organize new ones in some small rivers and in the upper reaches of the Krasivaya Mecha River. In case of emergence of technogenic catastrophes, they can serve as donors for the entire basin of the upper Don.     

Do plants adjust their sex allocation and secondary sexual morphology in response to their neighbours?

Background and aims

Changes in the sex allocation (i.e. in pollen versus seed production) of hermaphroditic plants often occur in response to the environment. In some homosporous ferns, gametophytes choose their gender in response to chemical cues sent by neighbours, such that spores develop as male gametophytes if they perceive a female or hermaphrodite nearby. Here it is considered whether a similar process might occur in the androdioecious angiosperm species Mercurialis annua, in which males co-occur with hermaphrodites; previous work on a Spanish population of M. annua found that individuals were more likely to develop as males at high density.

Methods

Using a novel approach to treat plants with leachate from pots containing males or hermaphrodites of M. annua, the hypothesis that individuals assess their mating opportunities, and adjust their sex expression accordingly, was tested through an exchange of chemical cues through the soil.

Key Results

For the population under study, from Morocco, no evidence was found for soil-signal-dependent sex expression: neither sex ratios nor sex allocation differed among experimental treatments.

Conclusions

The results imply either that the Moroccan population under study behaves differently from that previously studied in Spain (pointing to potential geographical variation in plasticity for sex expression), or that our method failed to capture the signals used by M. annua for adjustment of sex expression.     

The history of an invasion: phases of the explosive spread of the physid snail <Emphasis Type="Italic">Physella acuta</Emphasis> through Europe,Transcaucasia and Central Asia

Physella acuta (Draparnaud, 1805) is an aquatic pulmonate snail notorious for its high invasive potential. Of New World origin, this species now occurs on all continents. The aim of this study was to trace P. acuta dispersal through the Western Palearctic starting from its first arrival in the Old World and to determine possible drivers of this process. A range of literary sources as well as some rich European malacological collections have been consulted to ascertain the dates of the first finding of P. acuta in the countries of Europe, Transcaucasia, and Central Asia and to map the most significant localities. The shell characteristics of this species are so distinctive that they almost preclude misidentification and confusion with any native species. This allows one to rely on historical records, including older sources (18th to the first half of the 19th centuries). The earliest reliable records of P. acuta in the Old World can be dated to 1742, which implies an earlier date for the first arrival of the species in Europe, possibly in the 17th century. Its introduction may be explained either by accidental dispersal mediated by humans (for example, during transport of exotic plants to European botanical gardens) or by natural causes (long-distance dispersal from the Americas to Europe). Three successive phases leading to the current invasive range of P. acuta in the Western Palearctic can be identified. The species’ current Old World range can be viewed as a result of the interaction of natural and anthropogenic factors. The human-mediated drivers of dispersal include canal building, the aquarium trade and, more recently, alteration of natural freshwater habitats.     

The distribution of native and exotic plants in a naturally fragmented sagebrush-steppe landscape

We tested two general hypotheses for the diversity of native and exotic plants in an undisturbed, naturally fragmented sagebrush-steppe landscape in SE Idaho, USA, evaluating whether the MacArthur–Wilson hypothesis of island biogeography or a suite of environmental variables explained the distributions of native and exotic plants. We also tested a third hypothesis, which incorporated assumptions about the origin of exotic plants and their interaction with native plants. Of the three hypotheses we tested, the hypothesis that included exotic species best explained the diversity of the native plant community. The MacArthur–Wilson model of island biogeography did not explain the diversity of native (R ² = 0.13) or exotic plants well (R ² = 0.11), and the model fit the data poorly. A model of environmental variables better explained the diversity of native (R ² = 0.48) and exotic plants (R ² = 0.57), but it also fit the data poorly. Instead, proximity to a railroad explained the cover (R ² = 0.59) and richness of exotic plants (R ² = 0.63), which then explained the species richness of native plants (R ² = 0.34), and the model fit was adequate and had the lowest AIC value. This suggests that the transportation corridor had a significant, though indirect, effect on the native plant community, even in this undisturbed area. Moreover, explained variance, model fit, and the AIC model selection criteria favored the model with the railroad and exotic species over the M–W and environmental models. Since the habitat patches we studied were largely undisturbed by people and their activities, our results further suggest that the transportation corridor influenced the distribution of exotic plants by serving as a vector for colonization, rather than as a source of disturbance. Additionally, the results suggest that exotic plant species have had a negative effect on the diversity of the native plant community and have changed its composition. The results also support the inference that the nascent exotic plant community is influenced by source-sink (Pulliam in Am Nat 132:652–661, 1988) and assembly dynamics. In contrast, the native plant community appears to be more strongly influenced by environmental conditions associated with an elevational gradient, but there is evidence that the native community also has undergone directional change in species composition, associated with the invasion by non-native species.