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1.
Wahlenbergia cordiformis, a new species of the Lightfootia‐type is described and illustrated. It is currently only known from the farm Knolfontein, in the Swartruggens region, north east of Ceres in the Western Cape, South Africa. The closest relative of W. cordiformis is unclear, but it may be closely related to either W. tenella, W. nodosa, W. tenerrima, W. oligantha or W. neorigida. Wahlenbergia cordiformis is distinguished from them by its cordate, leaf‐like calyx lobes.  相似文献   

2.
Symbiotic algae of the ciliate Paramecium bursaria (Ehrenberg) Focker are key species in the fields of virology and molecular evolutionary biology as well as in the biology of symbiotic relationships. These symbiotic algae were once identified as Zoochlorella conductrix Brandt by the Dutch microbiologist, Beijerinck 120 years ago. However, after many twists and turns, the algae are today treated as nameless organisms. Recent molecular analyses have revealed several different algal partners depending on P. bursaria strains, but nearly all P. bursaria contains a symbiont belonging to either the so‐called ‘American’ or ‘European’ group. The absence of proper names for these algae is beginning to provoke ill effects in the above‐mentioned study areas. In the present study, we confirmed the genetic autonomy of the ‘American’ and ‘European’ groups and described the symbionts as Chlorella variabilis Shihira et Krauss and Micractinium reisseri Hoshina, Iwataki et Imamura sp. nov., respectively (Chlorellaceae, Trebouxiophyceae).  相似文献   

3.
The history, taxonomic placement, relationships, mode of trapping and cultivation of Nepenthes dubia Danser, an epiphytic fly‐eater from the cloud forests of the Bukit Barisan range of the west coast of Sumatra, are discussed. This is one of the eight species of Sect. Montanae Danser with ‘egg‐cup’ like pitchers. A key is provided to the eight species and they are formally named as Nepenthes Sect. Montanae subsect. Poculae‐ovis.  相似文献   

4.
5.
Aims: To test the effect of auxin‐treatment on plant pathogenic phytoplasmas and phytoplasma‐infected host. Methods and Results: In vitro grown periwinkle shoots infected with different ‘Candidatus Phytoplasma’ species were treated with indole‐3‐acetic acid (IAA) or indole‐3‐butyric acid (IBA). Both auxins induced recovery of phytoplasma‐infected periwinkle shoots, but IBA was more effective. The time period and concentration of the auxin needed to induce recovery was dependent on the ‘Candidatus Phytoplasma’ species and the type of auxin. Two ‘Candidatus Phytoplasma’ species, ‘Ca. P. pruni’ (strain KVI, clover phyllody from Italy) and ‘Ca. P. asteris’ (strain HYDB, hydrangea phyllody), were susceptible to auxin‐treatment and undetected by nested PCR or detected only in the second nested PCR in the host tissue. ‘Ca. P. solani’ (strain SA‐I, grapevine yellows) persisted in the host tissue despite the obvious recovery of the host plant and was always detected in the direct PCR. Conclusions: Both auxins induced recovery of phytoplasma‐infected plants and affected tested ‘Candidatus Phytoplasma’ species in the same manner, implying that the mechanism involved in phytoplasma elimination/survival is common to both, IAA and IBA. Significance and Impact of the Study: The results imply that in the case of some ‘Candidatus Phytoplasma’ species, IBA‐treatment could be used to eliminate phytoplasmas from in vitro grown Catharanthus roseus shoots.  相似文献   

6.
The aim of the present study was to assess the invasive potential of introduced non‐native and translocated fishes in Turkey (Anatolia and Thrace) by applying the Fish Invasiveness Screening Kit (FISK), a risk identification tool for freshwater fishes. From independent evaluations by two assessors of 35 species, calibration of FISK for Turkey identified a threshold score of 23, which reliably distinguished between potentially invasive (high risk) and potentially non‐invasive (medium to low risk) fishes for Anatolia (Asia) and Thrace (Europe). No species was categorized as ‘low risk’, 18 species were categorized as ‘medium risk’ and 17 as ‘high risk’ (two being ‘moderately high risk’, nine ‘high risk’, and six ‘very high risk’). The highest scoring species was gibel carp Carassius gibelio, whereas the lowest scoring species was Caucasian dwarf goby Knipowitschia caucasica, a translocated species. Assessor certainty in their responses averaged overall between ‘mostly uncertain’ and ‘mostly certain’, with red piranha Pygocentrus nattereri and topmouth gudgeon Pseudorasbora parva achieving the lowest and highest certainty values, respectively, and with overall significant differences in certainty between assessors. The results of the present study indicate that FISK is a useful and viable tool for identifying potentially invasive non‐native fishes in Turkey, a country characterized by natural biogeographical frontiers.  相似文献   

7.
Nearly 263 000 individual length–weight (L/W) data, collected during 2839 fish stock assessments between 1992 and 2009, were used to calculate L/W relationships (W = aLb) of 40 freshwater fish species from Flanders (Belgium). Roach Rutilus rutilus, perch Perca fluviatilis, three‐spine stickleback Gasterosteus aculeatus, gudgeon Gobio gobio and European eel Anguilla anguilla were the most abundant species in our surveys. Mean a and b values were in accordance with those available in FishBase. Mean b across all examined species is 3.094 (95% CL = 3.041 to 3.148) indicating a tendency towards slightly positive allometric growth in most fishes (thirty‐three species with b > 3). On the basis of a form factor equation, we characterized 2 species as ‘eel‐like’, 7 as ‘elongated’, 22 as ‘fusiform’ and 9 species as ‘short and deep’. This paper adds a substantial dataset to the yet scarcely available a and b values of European populations of freshwater fish species.  相似文献   

8.
The stomachs and intestines of 23 dusky dolphins incidentally caught in a trawl fishery off Patagonia were surveyed for helminths. All the dolphins were parasitized, with a total of 3,936 helminth individuals. Only five species occurred, of which three were common (prevalence ± 10%): Anisakis simplex, Braunina cordiformis and Hadwenius sp. A. simplex was present in all the dolphins and showed the highest abundance and mean intensity (104.9 individuals/infected host). B. cordiformis was next most common (87%), and Hadwenius sp. third (52.2%). A. simplex was found mostly in the stomach (94.8%), B. cordiformis in the duodenal ampulla (51.4%), and Hadwenius sp. in the stomach (64.5%). The rare species Corynosoma australe (immature specimens) and Pholeter gastrophilus occurred in the stomach. A. simplex and B. cordiformis showed a clumped distribution along the intestine. Brillouin's diversity and evenness indices for the intestinal helminth community were 0.329 and 0.393, respectively. The diversity values and the number of parasite species were within the range for other small cetaceans.  相似文献   

9.
Abstract: The osteology of Thaiichthys buddhabutrensis, nov. gen., from the Late Jurassic – Early Cretaceous of Thailand is described on the basis of a collection of well‐preserved specimens. The mode of preservation of the material allows describing the external anatomy, as well as some elements of the internal anatomy (braincase, elements of the vertebral column). Most of the cranial and postcranial skeleton shows a rather conservative anatomy for ‘semionotiformes’, but the jaw apparatus displays specializations. Variations observed in the ossification pattern of the skull roof and of the cheek, in the morphology of the median dorsal scales and in fin rays’ count indicate that caution should be applied when these characters are used in diagnoses and in phylogenetic analyses. A phylogenetic analysis including a set of gars, of ‘semionotiformes’, of Macrosemiiformes and of Halecomorphi shows the following features: (1) the monophyly of Holostei; (2) sister‐pair relationships between Tlayuamichin/Semiolepis, Isanichthys/’Lepidotes’ latifrons and Araripelepidotes/Pliodetes; (3) the latter pair, together with Thaiichthys and possibly ‘Lepidotes’ mantelli, are resolved as stem Lepisosteiformes; and (4) the ‘semionotiformes’ (a group gathering species of Semionotus and Lepidotes) do not form a clade.  相似文献   

10.
Two new species of Hedysarum, H. alii Haidar Ali & Qaiser sp. nov. and H. shahjinalense Haidar Ali & Qaiser sp. nov. are described from Chitral in Pakistan. As far as known, both new species are endemic to Chitral and are categorized as ‘Critically Endangered’ (CR). In addition, three other species of Hedysarum are recorded from Pakistan for the first time, viz. H. volkii Rech. f., H. brahuicum Boiss. and H. sericeum M. Bieb. These are also ‘Critically Endangered’ (CR) at a national level. A key to all 12 species of Hedysarum occurring in Pakistan is provided.  相似文献   

11.
12.
Years of selection for desirable fruit quality traits in dessert watermelon (Citrullus lanatus) has resulted in a narrow genetic base in modern cultivars. Development of novel genomic and genetic resources offers great potential to expand genetic diversity and improve important traits in watermelon. Here, we report a high‐quality genome sequence of watermelon cultivar ‘Charleston Gray’, a principal American dessert watermelon, to complement the existing reference genome from ‘97103’, an East Asian cultivar. Comparative analyses between genomes of ‘Charleston Gray’ and ‘97103’ revealed genomic variants that may underlie phenotypic differences between the two cultivars. We then genotyped 1365 watermelon plant introduction (PI) lines maintained at the U.S. National Plant Germplasm System using genotyping‐by‐sequencing (GBS). These PI lines were collected throughout the world and belong to three Citrullus species, C. lanatus, C. mucosospermus and C. amarus. Approximately 25 000 high‐quality single nucleotide polymorphisms (SNPs) were derived from the GBS data using the ‘Charleston Gray’ genome as the reference. Population genomic analyses using these SNPs discovered a close relationship between C. lanatus and Cmucosospermus and identified four major groups in these two species correlated to their geographic locations. Citrullus amarus was found to have a distinct genetic makeup compared to C. lanatus and Cmucosospermus. The SNPs also enabled identification of genomic regions associated with important fruit quality and disease resistance traits through genome‐wide association studies. The high‐quality ‘Charleston Gray’ genome and the genotyping data of this large collection of watermelon accessions provide valuable resources for facilitating watermelon research, breeding and improvement.  相似文献   

13.
Multiple species of Phlebotominae are vectors of Leishmania (Protozoa: Trypanosomatidae), which causes visceral leishmaniasis (VL) and cutaneous leishmaniasis (CL). To describe the Phlebotominae (Diptera: Psychodidae) related to the environments of black and gold howler monkeys Alouatta caraya (Humbodlt, 1812) (Primates: Atelidae), potential vectors were sampled in different landscapes and vertical strata of sleeping trees. Phlebotomine captured between December 2011 and March 2012 (2365 individuals) belonged to eight species, of which Nyssomyia neivai (Pinto, 1926) (61.4%) and Migonemyia migonei (França, 1920) (18.73%) were the most abundant, and Ny. withmani was recorded for the first time in the Chaco province. In the ‘peri‐domestic’ landscape, the phlebotomine were mainly captured in henhouses (78.7%), whereas the tree canopy in ‘rural’ and ‘wild’ landscapes yielded 31.2% and 29.1% of the phlebotomine, respectively. A significant association between the type of landscape and the species of phlebotomine was observed by multivariate analysis. Lutzomyia longipalpis (Lutz & Neiva, 1912) and Mg. migonei were associated with ‘peri‐domestic’ landscape, and Ny. neivai was associated with the ‘wild’ landscape. The results of this prospective study suggest that the interaction between phlebotomine and A. caraya could be a key factor with respect to understanding the epidemiology of leishmaniasis.  相似文献   

14.
In this paper, I describe Selaginella aculeatifolia Valdespino, a new species (probably a local endemic) from lowland forests in the foothills of Cerro de la Neblina in Venezuela, and compare it with morphologically close taxa, provide SEM of stem, leaves and spores, and discuss its conservation status. In addition, I provide a key to species in the Selaginella deltoides group. This species is characterized by its mat‐forming, creeping growth habit, having the upper surface of the lateral leaves hispidulous with short hairs or tooth‐like projections usually found submarginally, marginally and distally near the apices along the basiscopic halves of the laminae, and with conspicuous, straw‐colored midribs, as well as median leaves with conspicuously hyaline margins. These characters indicate an alliance of Selaginella aculeatifolia with a group of South American species: S. deltoides A. Braun, S. brevifolia Baker, and S. sandwithii Alston, here informally referred to as the ‘Selaginella deltoides group’.  相似文献   

15.
Allotetraploid oilseed rape (Brassica napus L.) is an agriculturally important crop. Cultivation and breeding of B. napus by humans has resulted in numerous genetically diverse morphotypes with optimized agronomic traits and ecophysiological adaptation. To further understand the genetic basis of diversification and adaptation, we report a draft genome of an Asian semi‐winter oilseed rape cultivar ‘ZS11’ and its comprehensive genomic comparison with the genomes of the winter‐type cultivar ‘Darmor‐bzh’ as well as two progenitors. The integrated BAC‐to‐BAC and whole‐genome shotgun sequencing strategies were effective in the assembly of repetitive regions (especially young long terminal repeats) and resulted in a high‐quality genome assembly of B. napus ‘ZS11’. Within a short evolutionary period (~6700 years ago), semi‐winter‐type ‘ZS11’ and the winter‐type ‘Darmor‐bzh’ maintained highly genomic collinearity. Even so, certain genetic differences were also detected in two morphotypes. Relative to ‘Darmor‐bzh’, both two subgenomes of ‘ZS11’ are closely related to its progenitors, and the ‘ZS11’ genome harbored several specific segmental homoeologous exchanges (HEs). Furthermore, the semi‐winter‐type ‘ZS11’ underwent potential genomic introgressions with B. rapa (Ar). Some of these genetic differences were associated with key agronomic traits. A key gene of A03.FLC3 regulating vernalization‐responsive flowering time in ‘ZS11’ was first experienced HE, and then underwent genomic introgression event with Ar, which potentially has led to genetic differences in controlling vernalization in the semi‐winter types. Our observations improved our understanding of the genetic diversity of different B. napus morphotypes and the cultivation history of semi‐winter oilseed rape in Asia.  相似文献   

16.
Abstract Studies were conducted to assess the numerical response of ground‐dwelling arthropods to a habitat management system (‘push–pull’) developed to control maize stemborers using spiders (Araneae) as an indicator group. In this cropping system, maize is intercropped with a stemborer moth‐repellent (push) plant while an attractant trap crop (pull) is planted around this intercrop. Two study sites in western Kenya and one site at the Grain Crops Institute of the Agricultural Research Council in Potchefstroom, South Africa, were sampled. Treatments comprised a maize monocrop and an intercrop of maize and desmodium, Desmodium uncinatum Jacq., with Napier grass, Pennisetum purpureum (Schumach), as a trap crop around the field (‘push–pull’) in each site. Experiments were laid out in a completely randomized design with four replications at each site. Ground‐dwelling spiders were sampled using a combination of pitfall traps and soil samples. A total of 2175 spiders, 78 species in 18 families, were recovered in Kenya and 284 spiders, 34 species in nine families, were recovered in South Africa. Lycosidae was the most abundant family, accounting for >50% of all individual spiders and 27.6% by species richness. Spiders were significantly more abundant at the Kenyan sites than in South Africa while species diversity was significantly higher in South Africa than at the Kenyan sites. At all sites, spider abundance was significantly higher in the ‘push–pull’ than in the maize monocrop plots. However, the overall spider diversity was only significantly higher in the ‘push–pull’ than in the maize monocrop plots in South Africa. Moreover, species dominance did not differ between the two cropping systems at all sites. The results showed that the ‘push–pull’ system evidently enhances overall abundance of spiders, illustrating its potential in further pest control in the maize agroecosystems where spiders may often be one of the most important predatory groups.  相似文献   

17.
18.
The skulls of 33 extant cat species were characterized through three‐dimensional geometric morphometrics using 20 landmarks. A principal component analysis (PCA) was performed with Procrustes fitted coordinates, and the PC‐scores were phylogenetically corrected by independent contrasts method. Three PCs allowed for the definition of five cat skull patterns. PC1: ‘snouted/massive‐headed cats’ (genus Panthera) opposing the ‘round‐headed small cats’ (genus Oncifelis, Prionailurus rubiginosus, Prionailurus bengalensis, among other small cats); PC2: ‘tapering‐headed cats’ (Neofelis nebulosa, Herpailurus yagouaroundi, Prionailurus planiceps) opposing the ‘stout‐headed cats’ (Acinonyx jubatus, Uncia uncia, Otocolobus manul, Felis margarita, and Felis nigripes); and PC3: ‘low profiled‐headed cats’ (mostly, Pr. planiceps). A sixth pattern, the ‘generalized skull’, observed in the Caracal lineage, genus Lynx, Leopardus pardalis, and Catopuma temminckii, indicates a morphological convergence among midsized‐cats. The morphological trends ‘snouted/massive’ and ‘round’ clearly denote a co‐evolution between size and shape. The other skull patterns evolved unrelatedly to the size (i.e. their allometric variations are not a size function). Nevertheless, each species comprises an amalgam of these patterns, so the influence of the size permeates, in some extent, the skull morphology along all cat lineages. The felid ecomorphological fit to hypercarnivory is obvious; however, different skull shapes in same‐sized species with similar habits, indicate that the variation in the skull morphology may result from phenotypic fluctuations, whose adaptive value (if indeed there is any) is still obscure. © 2011 The Linnean Society of London, Biological Journal of the Linnean Society, 2011, 103 , 176–190.  相似文献   

19.
Frankliniella occidentalis (Pergande) (Thysanoptera: Thripidae) is a major pest of strawberry. The efficacy of three species of predatory mites, Typhlodromips montdorensis (Schicha), Neoseiulus cucumeris (Oudemans) (both: Acari: Phytoseiidae), and Hypoaspis miles (Berlese) (Acari: Laelapidae), and their compatibility with spinosad for the control of this thrips was evaluated in commercial strawberry in spring. Low tunnel‐grown strawberry was treated with ‘water then mites’, ‘spinosad then mites’, or ‘mites then spinosad’. Predatory mites were released as single‐, two‐ and three‐species combinations. Overall, spinosad‐treated plants had fewer thrips than water‐treated plants (control). In all treatment regimes, each species of predatory mite reduced the number of thrips relative to those plants that received no mites. Predatory mites were most effective in reducing thrips when released after spinosad was applied. Any multiple‐species combination of predatory mites reduced thrips numbers more than single‐species releases. The two‐species combination of T. montdorensis (foliage inhabiting) and H. miles (soil dwelling) was the most effective in suppressing thrips. The next most effective combination was a three‐species release. Of multiple‐species combinations, the two‐species combination of T. montdorensis and N. cucumeris was the least effective in suppressing thrips numbers. The spinosad and mites only temporarily reduced the numbers of F. occidentalis. This suggests that further application of predatory mites, spinosad, or both is required to maintain F. occidentalis populations below an economically damaging level.  相似文献   

20.
In the course of studies to typify what has been regarded as the most widespread and common of the endemic Philippines species of Nepenthes, N. alata Blanco, we were able to review the morphological variation in what we previously regarded as a polymorphic species. This led us to redelimit that species in a narrower sense, to resurrect N. graciliflora Elmer, and to recognise N. negros sp. nov., here assessed as ‘Critically Endangered’ (CR) using the IUCN standard. The Nepenthes alata group is characterised and a key to its species is provided.  相似文献   

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