Life history responses of <Emphasis Type="Italic">Daphnia longispina</Emphasis> to mosquitofish (<Emphasis Type="Italic">Gambusia holbrooki</Emphasis>) and pumpkinseed (<Emphasis Type="Italic">Lepomis gibbosus</Emphasis>) kairomones

In the present study, the effect of chemical cues from two fish species (mosquitofish and pumpkinseed), at different concentrations, was tested in life history experiments with Daphnia longispina. The two fish species used represent the most abundant planktivores of many Mediterranean shallow lakes (SW Europe), where the indigenous fish communities have been replaced by such exotic assemblages. Results have shown a similar response of D. longispina to both fish species: kairomones stimulated daphnids to produce more offspring, which resulted in higher fitness (r), relatively to a fishless control. Fish presence also induced an earlier first reproduction, a smaller size at maturity of daphnids, and the production of smaller-sized neonates. Significant correlations with fish concentration (indirect measure of fish kairomone concentration) were found for size at maturity and neonate size, for both fish species. These results are in accordance to the “positive response” observed by other authors, which represents a defence mechanism to face losses caused by fish predators. The chemically mediated size reduction of mature females and neonates is an adaptive response to the size-selective predation exerted by fish. Pumpkinseed introduction is very recent in the lake of origin of the daphnids used in the experiments and its kairomone produced similar effects to mosquitofish in the life history of D. longispina. These results are contrary to the existence of a species-specific kairomone and support the hypothesis of a general fish kairomone. Guest editor: Piet Spaak Cladocera: Proceedings of the 7th International Symposium on Cladocera     

Identifying hybridizing taxa within the <Emphasis Type="Italic">Daphnia longispina</Emphasis> species complex: a comparison of genetic methods and phenotypic approaches

Daphnia galeata Sars, D. longispina O. F. Müller and D. cucullata Sars (Crustacea: Cladocera) are closely related species which often produce interspecific hybrids in natural populations. Several marker systems are available for taxon determination in this hybridizing complex, but their performance and reliability has not been systematically assessed. We compared results from identifications by three molecular methods. More than 1,200 individuals from 10 localities in the Czech Republic were identified as parental species or hybrids by allozyme electrophoresis and the analysis of the restriction fragment length polymorphism of the internal transcribed spacer (ITS-RFLP); over 440 of them were additionally analyzed and identified by 12 microsatellite loci. Identification by microsatellite markers corresponded well with allozyme analyses. However, consistent discrepancies between ITS-RFLP and other markers were observed in two out of 10 studied localities. Although some marker discrepancies may have been caused by occasional recent introgression, consistent deviations between ITS-RFLP and other markers suggest a long-term maintenance of introgressed alleles. These results warn against its use as a sole identification method in field studies. Additionally, we quantitatively evaluated the discriminatory power of geometric morphometric (elliptic Fourier) analysis of body shapes based on photos of over 1,300 individuals pre-classified by allozyme markers. Furthermore, a randomly selected subset of 240 individuals was independently determined from photos by several experts. Despite a tendency for morphological divergence among parental Daphnia species, some taxa (especially D. galeata, D. longispina, and their hybrids) substantially overlapped in their body shapes. This was reflected in different determination success for particular species and hybrids in discriminant analysis based on shape data as well as from photographs.     

The ecological niches of <Emphasis Type="Italic">Bythotrephes</Emphasis> and <Emphasis Type="Italic">Leptodora:</Emphasis> lessons for predicting long-term effects of invasion

We here exploit two large datasets on zooplankton in Norwegian lakes, spanning a wide range of geographical, physical, chemical and biological properties, to assess the ecological niches and habitats of Bythotrephes longimanus and Leptodora kindtii. The species overlapped geographically, yet co-occurred only in a limited number of lakes. Bythotrephes inhabited virtually all types of lakes, except alpine localities and productive lakes dominated by cyprinid communities where the hyaline Leptodora was most abundant. The zooplankton communities also differed in Bythotrephes and Leptodora lakes, probably both reflecting different predatory regimes, but also water quality and other lake-specific properties. We found no evidence for species being excluded by the presence of Bythotrephes, rather the diversity in general was higher in lakes with these predators present compared with those without. We found, however, a very close association between Bythotrephes and Daphnia galeata and to some extent also between Bythotrephes and D. longispina, suggesting that these species also may benefit from Bythotrephes invasion. Both Bythotrephes and Leptodora species occur naturally in this region, and knowledge about the ecological preferences and the zooplankton community composition in Bythotrephes—and Leptodora lakes will provide valuable information about the long-term effects of Bythotrephes invasion and potential interaction with of Leptodora as top invertebrate predator.     

Reproduction strategies of <Emphasis Type="Italic">Daphnia pulicaria</Emphasis> population in a high mountain lake of Southern Spain

For three consecutive years, a population study of Daphnia pulicaria was undertaken in Río Seco Lake, a small high-mountain lake, in order to elucidate the reproductive strategies adopted by Daphnia in this system. Daphnia appears to colonize this lake every spring by hatching from ephippia and reproduce by means of subitaneous (non-diapausing) and ephippial (diapausing) eggs. D. pulicaria in this lake is an obligate parthenogenetic population. There is a short time period for subitaneous egg production and a much longer period for ephippial egg production. The contribution of subitaneous eggs to Daphnia population density and structure appears to be low. Diapause onset showed a high temporal synchronization in the three studied years in Río Seco Lake, and day-length emerged as the main cue triggering diapause onset and the main explanatory factor for the proportion of ephippial females observed. The development and reproduction of D. pulicaria in Río Seco Lake involves taking a gamble on resting forms to guarantee inter-annual Daphnia persistence in the lake, giving priority to investment in future generations. Guest editor: Piet Spaak Cladocera: Proceedings of the 7th International Symposium on Cladocera     

Morphological and phylogenetic analyses of <Emphasis Type="Italic">Uromyces appendiculatus</Emphasis> and <Emphasis Type="Italic">U. vignae</Emphasis> on legumes in Japan

Uromyces appendiculatus, inclusive of three varieties, is distinguished from U. vignae primarily by the position of urediniospore germ pores and putative host specificity. However, opinions concerning these morphological and physiological features as taxonomic characters have varied greatly, and distinction of these species has often been confused. To clarify the taxonomy of these two species, morphological features of urediniospores and teliospores of 225 rust fungus specimens on species of Phaseolus, Vigna, Apios, Lablab, and Dunbaria were examined by light microscopy and scanning electron microscopy. Forty-five specimens were subjected to molecular phylogenetic analyses. As a result, the position of germ pores in urediniospores and the teliospore-wall thickness were considered as good characters to separate three morphological groups. In molecular analyses, the specimens fell into two and three clades based on the nucleotide sequence at D1/D2 domain of LSU rDNA and ITS regions, respectively. One of the D1/D2 clades corresponded to one morphological group whereas another D1/D2 clade included two other morphological groups. In contrast, each of the three ITS clades corresponded to a separate morphological group. Neither morphological groups nor molecular clades were host limited. It is suggested that the three morphological groups that corresponded to three distinct ITS clades constitute distinct species.Contribution no. 186 from the Laboratory of Plant Parasitic Mycology, Institute of Agriculture and Forestry, University of Tsukuba, Japan     

Hares in Corsica: high prevalence of <Emphasis Type="Italic">Lepus corsicanus</Emphasis> and hybridization with introduced <Emphasis Type="Italic">L. europaeus</Emphasis> and <Emphasis Type="Italic">L. granatensis</Emphasis>

The Italian hare, Lepus corsicanus, was first described in Corsica more than 100 years ago, but the knowledge on the status of the species in this island remains scarce. Moreover, frequent introductions of thousands of individuals from other hare species, namely Lepus europaeus and Lepus granatensis, into Corsica are known to have occurred and an updated assessment of the prevalence of L. corsicanus in Corsica is therefore of utmost importance. Here, to estimate the relative prevalence of the hare species present in Corsica, we conducted a molecular analysis on 67 samples collected by hunters between 2002 and 2007 in 36 Corsican communes. Sequencing of portions of the nuclear gene transferrin and of the control region of the mitochondrial DNA allowed classifying most of the collected samples as belonging to L. corsicanus (70.1%). Of the sampled Corsican communes, 86.1% contained this species, while only in 11.1%, L. europaeus was present. Three of the analyzed specimens showed an inconsistent molecular assignment between markers suggesting a hybrid origin: L. corsicanus × L. europaeus, L. corsicanus × L. granatensis, and L. europaeus × L. granatensis. The first two cases of hybridization had never been described in nature, even in studies focusing on hares from Italy where L. corsicanus and L. europaeus are often sympatric. These results stress the real risk of corrosion of the native gene pool of L. corsicanus via hybridization with introduced species. We highlight the need of urgently rethinking the management plan of hare populations in Corsica.     

Revised treatment of <Emphasis Type="Italic">Memecylon</Emphasis> sect. <Emphasis Type="Italic">Afzeliana</Emphasis> (<Emphasis Type="Italic">Melastomataceae: Olisbeoideae</Emphasis>), including three new species from Cameroon

Summary  Seven new names at species rank are proposed in Memecylon sect. Afzeliana Jacq.-Fél., a group of forest shrubs and small trees confined to Guineo-Congolian Africa. The group is centred in Cameroon, where 17 of the 20 species occur. A new flower type, the “star-flower” in Memecylon is revealed, and its taxonomic and ecological importance discussed. Three new, locally endemic species from the South West Province of Cameroon are described, mapped and illustrated: M. kupeanum R. D. Stone, Ghogue & Cheek, M. bakossiense R. D. Stone, Ghogue & Cheek, and M. rheophyticum R. D. Stone, Ghogue & Cheek. Two new names, M. accedens R. D. Stone, Ghogue & Cheek and M. hyleastrum R. D. Stone & Ghogue and one new combination, M. mamfeanum (Jacq.-Fél.) R. D. Stone, Ghogue & Cheek are provided at species level for three taxa originally proposed as varieties of M. afzelii G. Don. The taxon M. arcuatomarginatum var. simulans Jacq.-Fél. is also elevated to species status, as M. simulans (Jacq.-Fél.) R. D. Stone & Ghogue. Conservation assessments are provided for all the newly named taxa. A key is provided to the species of Memecylon sect. Afzeliana.     

Role of melatonin in the control of depth distribution of <Emphasis Type="Italic">Daphnia magna</Emphasis>

Previous studies confirmed the presence of melatonin in Daphnia magna and demonstrated diurnal fluctuations in its concentration. It is also known that in several invertebrate species, melatonin affects locomotor activity. We tested the hypothesis that this hormone is involved in the regulation of Daphnia diel vertical migration (DVM) behaviour that is well recognized as the adaptive response to predation threat. Using ‘plankton organs’, we studied the effect of three concentrations of exogenous melatonin (10⁻⁵, 10⁻⁷, 10⁻⁹ M) on DVM of both female and male D. magna in the presence or absence of chemical cue (kairomone) of planktivorous fish. Depth distribution was measured six times a day, using infrared-sensitive closed circuit television cameras. Our results showed a significant effect of melatonin on the mean depth of experimental populations, both males and females, but only when melatonin was combined with fish kairomone. Females stayed, on average, closer to the surface than males, both responding to the presence of kairomone by descending to deeper strata. In the presence of exogenous melatonin and with the threat of predation, Daphnia stayed closer to the surface and their distribution was more variable than that of individuals, which were exposed to the kairomone alone. Approaching the surface in the presence of predation threat seems to be maladaptive. We postulate the role of melatonin as a stress signal inhibitor in molecular pathways of response to predation threat in Cladocera.     

Mapping of quantitative trait loci for resistance to <Emphasis Type="Italic">Mycosphaerella pinodes</Emphasis> in <Emphasis Type="Italic">Pisum sativum</Emphasis> subsp. <Emphasis Type="Italic">syriacum</Emphasis>

Aschochyta blight, caused by Mycosphaerella pinodes, is one of the most economically serious pea pathogens, particularly in winter sowings. The wild Pisum sativum subsp. syriacum accession P665 shows good levels of resistance to this pathogen. Knowledge of the genetic factors controlling resistance to M. pinodes in this wild accession would facilitate gene transfer to pea cultivars; however, previous studies mapping resistance to M. pinodes in pea have never included this wild species. The objective of this study was to identify quantitative trait loci (QTL) controlling resistance to M. pinodes in P. sativum subsp. syriacum and to compare these with QTLs previously described for the same trait in P. sativum. A population formed by 111 F_6:7 recombinant inbred lines derived from a cross between accession P665 and a susceptible pea cultivar (Messire) was analysed using morphological, isozyme, RAPD, STS and EST markers. The map developed covered 1214 cM and contained 246 markers distributed in nine linkage groups, of which seven could be assigned to pea chromosomes. Six QTLs associated with resistance to M. pinodes were detected in linkage groups II, III, IV and V, which collectively explained between 31 and 75% of the phenotypic variation depending of the trait. While QTLs MpIII.1 and MpIII.2 were detected both for seedlings and field resistance, MpV.1 and MpII.1 were specific for growth chamber conditions and MpIII.3 and MpIV.1 for field resistance. Quantitative trait loci MpIII.1, MpII.1, MpIII.2 and MpIII.3 may coincide with other QTLs associated with resistance to M. pinodes previously described in P. sativum. Four QTLs associated with earliness of flowering were also identified. While dfIII.2 and dfVI.1, may correspond with other genes and QTLs controlling earliness in P. sativum, dfIII.1 and dfII.1 may be specific to P. sativum subsp. syriacum. Flowering date and growth habit were strongly associated with resistance to M. pinodes in the field evaluations. The relation observed between earliness, growth habit and resistance to M. pinodes is discussed.     

<Emphasis Type="Italic">Funastrum rupicola</Emphasis> (<Emphasis Type="Italic">Apocynaceae:</Emphasis><Emphasis Type="Italic">Asclepiadoideae</Emphasis>), a new species from Bolivia

Summary   Funastrum rupicola Goyder, a new species of Apocynaceae: Asclepiadoideae from Bolivia, is described and illustrated. The conservation status of this species is assessed.     

<Emphasis Type="Italic">Typhonium stigmatilobatum</Emphasis> (<Emphasis Type="Italic">Araceae</Emphasis> tribe <Emphasis Type="Italic">Areae</Emphasis>), a new species from Vietnam

Summary   Typhonium stigmatilobatum V. D. Nguyen, a new species from Vietnam, is described and illustrated.     

The induction of diapause in <Emphasis Type="Italic">Moina</Emphasis> by species-specific chemical cues

The ability to change the reproduction mode and produce diapausing eggs, which is prevalent in many zooplankton species, significantly impacts on the evolution and ecology of aquatic communities. The production of diapausing eggs is controlled by multiple effects of biotic and abiotic factors, including infochemicals. We have investigated the effects of chemicals exuded by conspecifics and ecologically close competing congers, Moina brachiata and M. macrocopa, which coexist in the same water body, and by larger Cladocera species (Daphnia magna) on the change of reproduction mode, specific growth rate and fecundity of M. brachiata and M. macrocopa females. The production of gametogenetic eggs in both species was detected only in waters from crowded cultures of conspecifics. The water from crowded cultures of conspecifics reduced the specific growth rate of the juvenile females of both species that later switched to gametogenesis. While it either did not affect (in M. macrocopa) or even increase (in M. brachiata) the specific growth rate of the juvenile females that later reproduced by parthenogenesis. Females of M. macrocopa released significantly fewer neonates in the water from crowded cultures of conspecifics than in all other treatments, while the fecundity of M. brachiata females was the same in all treatments. To understand the phenomenon of diapause induction under the effect of chemical cues in zooplankton, a link between laboratory tests and ecological research should be established, and the chemical composition of the signals should be determined.     

<Emphasis Type="Italic">Phuphanochloa,</Emphasis> a new bamboo genus (<Emphasis Type="Italic">Poaceae</Emphasis>: <Emphasis Type="Italic">Bambusoideae</Emphasis>) from Thailand

Summary  A new monotypic bamboo genus Phuphanochloa (Poaceae: Bambusoideae) from north-eastern Thailand is described, together with a new species, P. speciosa.     

Antimicrobial Activity and Biodiversity of Endophytic Fungi in <Emphasis Type="Italic">Dendrobium</Emphasis><Emphasis Type="Italic">devonianum</Emphasis> and <Emphasis Type="Italic">Dendrobium thyrsiflorum</Emphasis> from Vietman

Endophytic fungi are rich in orchids and have great impacts on their host plants. 53 endophytes (30 isolates from Dendrobium devonianum and 23 endophytic fungi from D. thyrsiflorum) were isolated, respectively, from roots and stems of Dendrobium species. All the fungi were identified by way of morphological and/or molecular biological methods. 30 endophytic fungi in D. devonianum were categorized into 11 taxa and 23 fungal endophytes in D. thyrsiflorum were grouped into 11 genera, respectively. Fusarium was the dominant species of the two Dendrobium species in common. Antimicrobial activity of ethanol extract of fermentation broth of these fungi was explored using agar diffusion test. 10 endophytic fungi in D. devonianum and 11 in D. thyrsiflorum exhibited antimicrobial activity against at least one pathogenic bacterium or fungus among 6 pathogenic microbes (Escherichia coli, Bacillus subtilis, Staphylococcus aureus, Candida albicans, Cryptococcus neoformans, and Aspergillus fumigatus). Out of the fungal endophytes isolated from D. devonianum and D. thyrsiflorum, Phoma displayed strong inhibitory activity (inhibition zones in diameter >20 mm) against pathogens. Epicoccum nigrum from D. thyrsiflorum exhibited antibacterial activity even stronger than ampicillin sodium. Fusarium isolated from the two Dendrobium species was effective against the pathogenic bacterial as well as fungal pathogens. The study reinforced the assumption that endophytic fungi isolated from different Dendrobium species could be of potential antibacterial or antifungal resource.     

Mapping of the <Emphasis Type="Italic">multifoliate pinna</Emphasis> (<Emphasis Type="Italic">mfp</Emphasis>) leaf-blade morphology mutation in grain pea <Emphasis Type="Italic">Pisum sativum</Emphasis>

The multifoliate pinna (mfp) mutation alters the leaf-blade architecture of pea, such that simple tendril pinnae of distal domain are replaced by compound pinna blades of tendrilled leaflets in mfp homozygotes. The MFP locus was mapped with reference to DNA markers using F₂ and F_2:5 RIL as mapping populations. Among 205 RAPD, 27 ISSR and 35 SSR markers that demonstrated polymorphism between the parents of mapping populations, three RAPD markers were found linked to the MFP locus by bulk segregant analyses on mfp/mfp and MFP/MFP bulks assembled from the F_2:5 population. The segregational analysis of mfp and 267 DNA markers on 96 F₂ plants allowed placement of 26 DNA markers with reference to MFP on a linkage group. The existence of common markers on reference genetic maps and MFP linkage group developed here showed that MFP is located on linkage group IV of the consensus genetic map of pea.     

Dynamics of <Emphasis Type="Italic">Vulmar/VulMITE</Emphasis> group of transposable elements in <Emphasis Type="Italic">Chenopodiaceae</Emphasis> subfamily <Emphasis Type="Italic">Betoideae</Emphasis>

Transposable elements are important factors driving plant genome evolution. Upon their mobilization, novel insertion polymorphisms are being created. We investigated differences in copy number and insertion polymorphism of a group of Mariner-like transposable elements Vulmar and related VulMITE miniature inverted-repeat transposable elements (MITEs) in species representing subfamily Betoideae. Insertion sites of these elements were identified using a modified transposon display protocol, allowing amplification of longer fragments representing regions flanking insertion sites. Subsequently, a subset of TD fragments was converted into insertion site-based polymorphism (ISBP) markers. The investigated group of transposable elements was the most abundant in accessions representing the section Beta, showing intraspecific insertion polymorphisms likely resulting from their recent activity. In contrast, no unique insertions were observed for species of the genus Beta section Corollinae, while a set of section-specific insertions was observed in the genus Patellifolia, however, only two of them were polymorphic between P. procumbens and P. webbiana. We hypothesize that Vulmar and VulMITE elements were inactivated in the section Corollinae, while they remained active in the section Beta and the genus Patellifolia. The ISBP markers generally confirmed the insertion patterns observed with TD markers, including presence of distinct subsets of TE insertions specific to Beta and Patellifolia.     

A new methanol assimilating yeast, <Emphasis Type="Italic">Ogataea</Emphasis><Emphasis Type="Italic">parapolymorpha</Emphasis>, the ascosporic state of <Emphasis Type="Italic">Candida</Emphasis><Emphasis Type="Italic">parapolymorpha</Emphasis>

Ogataea parapolymorpha sp. n. (NRRL YB-1982, CBS 12304, type strain), the ascosporic state of Candida parapolymorpha, is described. The species appears homothallic, assimilates methanol as is typical of most Ogataea species and forms hat-shaped ascospores in asci that become deliquescent. O. parapolymorpha is closely related to Ogataea angusta and Ogataea polymorpha. The three species can be resolved from gene sequence analyses but are unresolved from fermentation and growth reactions that are typically used for yeast identification. On the basis of multiple isolates, O. angusta is known only from California, USA, in association with Drosophila and Aulacigaster flies, O. parapolymorpha is predominantly associated with insect frass from trees in the eastern USA but O. polymorpha has been isolated from various substrates in the USA, Brazil, Spain and Costa Rica.     

Trophic ecology of an aquatic mite (<Emphasis Type="Italic">Piona carnea</Emphasis>) preying on <Emphasis Type="Italic">Daphnia pulex</Emphasis>: effects of predator density,nutrient supply and a second predator (<Emphasis Type="Italic">Chaoborus americanus</Emphasis>)

As compared to other aquatic invertebrates, relatively little is known about the ecology of predaceous, pelagic water mites. Studies to date do, however, show that water mites can be important components of aquatic food webs. Here, we used manipulative field experiments to better understand the trophic ecology of a predaceous water mite (Piona carnea). Three experiments were conducted that examined (i) the effect of P. carnea density on the per-capita interaction strength (PCIS) of P. carnea preying on zooplankton; (ii) how the effects of P. carnea predation change with prey productivity; and (iii) how P. carnea interacts with another pelagic predator (Chaoborus americanus) to affect a shared prey species (Daphnia pulex). Results from the first experiment showed that P. carnea can strongly impact D. pulex populations, and that the PCIS of P. carnea decreases with an increase in P. carnea density. The second experiment showed that the effects of P. carnea on D. pulex populations depend on bottom-up factors that influence D. pulex population biomass and the reproductive potential of a D. pulex population relative to its size. The third experiment uncovered a non-additive interaction between P. carnea and C. americanus that resulted in a risk reducing situation for D. pulex in the presence of both predators. Together these experiments show that P. carnea imposes a strong negative impact on D. pulex, that the magnitude of this negative impact is dependent on the P. carnea density and the productivity of the system, and that the trophic ecology of P. carnea is modified by coexisting predator species.     

New species in <Emphasis Type="Italic">Barleria</Emphasis> sect. <Emphasis Type="Italic">Stellatohirta</Emphasis> (<Emphasis Type="Italic">Acanthaceae</Emphasis>) from Africa

Summary  Three new species are described in Barleria L. sect. Stellatohirta M. Balkwill from tropical Africa: B. aristata from south-central Tanzania, B. aenea from south-western Tanzania and northeast Zambia, and B. purpureotincta from south-western Zambia. Their affinities and conservation status are discussed.