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1.
Autochthonous plant species are heavily threatened by the increasing spread of invasive insects. The spatial distribution of invasive species’ hosts is likely to play a pivotal role in the establishment and further expansion of the invading species; more specifically, distance and density dependent (DDD) processes linked to plant spatial arrangement are crucial in determining susceptibility to attack, but they have usually been overlooked in invasive research. We take a spatially explicit approach to evaluate potential DDD processes in the interaction between Paysandisia archon, a tropical lepidopteran recently introduced in Spain, and the endemic Mediterranean dwarf palm (Chamaerops humilis) in Mallorca (Balearic Islands). Specifically, we used spatial marked point pattern analyses, which allowed testing whether DDD processes affect attack probability and intensity on three dwarf palm populations corresponding to three different invasion phases (i.e., infestation core, early expansion, and expansion front). Our approach also allowed evaluation of whether and how intrinsic palm traits (size, sex) alter the proneness to P. archon attack over a range of spatial scales. The occurrence and nature of DDD effects on C. humilis performance varied largely among localities. At the infestation core, our analyses revealed positive density dependence, i.e., reduced damage at high densities or proximity to conspecific neighbors. By contrast, the early expansion locality showed negative density dependence of C. humilis performance, whereas at the expansion front, there was no evidence of DDD effects. Larger palms were consistently more prone to P. archon attack than small ones up to scales of 50 m. We found no evidence that palm sex altered the probability of attack by P. archon. Our results highlight the importance of spatially explicit analyses for assessing invasive events and point to the need of early interventions and prioritizing management efforts on larger palms in order to guarantee the conservation of autochthonous dwarf palm populations.  相似文献   

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There are three species of Phoenix (Arecaceae) in the territory of the European Union, P. canariensis, P. dactylifera and P. theophrasti, found in wild-native populations, feral, planted and intermediate states, accounting each for thousands of individuals. The EU Habitats Directive has addressed the conservation of P. theophrasti and P. canariensis under the habitat type 9370, ‘Palm groves of Phoenix,’ but neglected to include the wild-growing populations of P. dactylifera palms in southern Spain. In this paper, we survey the habitats and status of both representative native and naturalized populations of Phoenix, in total 103, through fieldwork, image analysis and review of literature. We underline the significance of feral populations and palms originating from ancient abandoned plantations, existing in protected areas as a reservoir of genetic variation. We conclude that, in order to improve their conservation status by adequate protection and conservation management, the concept of Phoenix palm groves in the Habitats Directive should be redefined to include the western group of P. dactylifera and the various habitats of P. canariensis and P. theophrasti that do not appear in the current definition.  相似文献   

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The red palm weevil, Rhynchophorus ferrugineus (Olivier) (Coleoptera, Curculionidae), is an important pest of palms. It has recently colonized the Mediterranean Basin, where it is a serious problem on ornamental Phoenix canariensis (Chabaud) palms. The efficacy of Steinernema carpocapsae (Weiser) (Nematoda: Steinernematidae) in a chitosan formulation (Biorend R®) against this weevil in a semi-field trial including both preventative and curative assays has been studied. Our results prove the potential of this nematode to control R. ferrugineus. Efficacies around 80% were obtained in the curative assay, and up to 98% in the preventative treatment. Applications repeated every 2–3 weeks during the critical flight periods could prove effective to protect palms from this weevil in the Mediterranean Basin.  相似文献   

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Our aim was to assess parental and population genetic variability in a partially nested set of breeding populations from the breeding program at Dami Research Station (West New Britain, PNG). Twenty microsatellite markers were tested for their ability to characterize genetic variation in oil palm populations bred at Dami Research Station. One hundred and twenty six individuals, including 100 F1 tenera hybrids of Dami Deli crossed with either AVROS, Ghana or AVROS/Ghana breeding lines were analysed. Eighteen of these markers were polymorphic within and among populations, amplifying 103 alleles in oil palm. Three individuals of other palm species (Cocos nucifera and two Phoenix spp.) were included as outliers. With these markers we have the power to distinguish individual palms, hence we conclude that they will facilitate association of markers with important phenotypic traits to streamline future breeding and selection.  相似文献   

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A first step in protecting groups of similarly structured organisms is to place them into discrete taxa. Molecular genetics and phylogeny allow us to rebuild the evolutionary history of these taxa. The Neotropics has roughly 34% of Earth’s primate diversity. However, the systematics of Neotropical primates is complex and controversial. The untufted (gracile) capuchins are traditionally classified as four species: Cebus albifrons, C. capucinus, C. olivaceus, and C. kaapori. Of these, Cebus albifrons has confusing intraspecific systematics with a large number of fragmented and isolated populations throughout its geographical distribution, and up to 13 morphological subspecies. The number of taxa of this species in Ecuador, some areas of northern and eastern Colombia, and Trinidad Island is particularly debated. Primatologists have defined two taxa of C. albifrons in Ecuador: a trans-Andean population: C. a. aequatorialis (or C. aequatorialis) and a cis-Andean population: C. a. yuracus (or C. yuracus). To better understand the systematics of this species, we sequenced the mitogenomes of 136 Cebus albifrons, two Cebus olivaceus, and one Cebus kaapori. Our phylogenetic analyses revealed at least nine significantly different haplogroups of C. albifrons in Ecuador, four of which contained exemplars from both the trans-Andean Pacific Ecuador and the cis-Andean Ecuadorian Amazon. The splits of these Ecuadorian haplogroups, and the initial diversification within them, occurred during the Middle to Late Pliocene and the beginning of the Pleistocene. Individuals we analyzed from Vichada Department in eastern Colombia were genetically distinct from other groups of C. albifrons, agreeing with morphological studies which consider it a full subspecies (C. a. albifrons). Phylogenetic analyses showed two different gracile capuchin taxa on Trinidad Island: C. a. trininatis and C. o. brunneus. We conclude that a large portion of the gracile capuchin taxa form a unique species with a complex of populations and subspecies. The species has conserved its reproductive integrity by repeated episodes of reticulation and high levels of gene flow.  相似文献   

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As deforestation and land-use/land-cover change advance in tropical forest regions, an understanding of how plants adjust phenology and reproductive dynamics to altered landscapes can provide insights into plasticity, productivity, and population persistence. We compared the reproductive phenology, sex expression, and flower and fruit production of two monoecious Amazonian palms, Attalea phalerata and Attalea speciosa, in old-growth forest and as remnant trees growing in actively grazed pastures. Using 2 years of phenology data collected from natural populations near Vila Extrema, Rondônia, and eastern Acre, Brazil, we compared flowering and fruiting in the two habitats and tested for effects of palm height, crown size, and light availability on inflorescence and sex expression. Forest conversion to pasture stimulated greater overall flowering and fruiting in individual Attalea palms. As a population, remnant pasture palms continuously bore flowers and fruits year-round, while forest palms flowered seasonally in isolated peaks with consecutive months of inactivity. Crown size and greater light exposure affected flowering and fruiting dynamics in A. phalerata and A. speciosa, respectively, and increased light availability shifted A. speciosa sex expression towards greater female investment, primarily through regulation of sex determination and bud abortion. Removal of tropical forest does not always lead to the downfall of remnant tree populations, and under favorable conditions, such as abandonment of cropland and pasture, higher levels of reproduction can facilitate recovery of future generations. Tree species with flexible sex expression may be particularly resilient in the face of land-use and land-cover change.  相似文献   

8.
An assemblage of species of the genus Baylea (B. subpenea (Netchaev, 1894), B. vjatkensis Mazaev, 2015, B. praeburtasorum sp. nov., and B. shilovskyi sp. nov.) from the Lower Kazanian Substage (Middle Permian) is described. It is shown that this assemblage is phylogenetically connected with the Late Kazanian species B. rigida Mazaev, 2015, B. foraminata Mazaev, 2015, B. chimbulatiensis Mazaev, 2015, B. nemdaensis Mazaev, 2015, and B. burtasorum (Golowkinsky, 1868). Index species of three stratigraphic intervals are recognized: B. praeburtasorum sp. nov.–B. shilovskyi sp. nov., B. rigida–B. foraminata, and B. burtasorum. The morphology and polymorphism of the studied species are discussed.  相似文献   

9.
Leaf area is an important parameter in oil palm breeding as it is positively correlated with oil yield. However, measurement of leaf area is tedious and also destructive. In the present study, a breeding population with 145 palms derived from a cross between Deli Dura and Avros Pisifera was used to construct a high-density linkage map and identify quantitative trait loci (QTL) for leaf area in oil palm. Using genotyping by sequencing, a linkage map containing 2413 SNPs was constructed. The total length of the linkage map was 1161.89 cM, with an average marker spacing of 0.48 cM. Based on the continuous phenotyping of leaf area from 2010 to 2015, two suggestive QTL for leaf area were mapped on chromosomes (Chr) 3 and 9. The allelic effects of the QTL associated with leaf area in the mapping population were estimated by linear regression using ordinary least squares method. The QTL on Chr 9 explained 13.3% of phenotypic variation for leaf area. A candidate gene, ARC5, within the narrow interval of QTL on Chr 9 was identified. The gene was significantly higher expressed in leaf than root and fruit of oil palm. This high-quality and SNP-based map supplies a base to fine map QTL for agronomic traits in oil palm, and the markers closely linked to the stable QTL may be used in marker-assisted selection in oil palm breeding.  相似文献   

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The red palm mite, Raoiella indica (Acari: Tenuipalpidae), is an important pest of palms (Arecaceae) and other species within the Zingiberaceae, Musaceae and Strelitziaceae families. Raoiella indica was discovered in the USA (Palm Beach and Broward counties, Florida) late in 2007, and it subsequently spread to other Florida counties. The predatory mite Amblyseius largoensis (Acari: Phytoseiidae) has been found associated with R. indica in Florida. In order to verify whether A. largoensis can develop and reproduce when feeding exclusively on R. indica, the biology of this predator was evaluated on various food sources, including R. indica. Five diets [R. indica, Tetranychus gloveri¸ Aonidiella orientalis, Nipaecocus nipae, oak (Quercus virginiana) pollen] and a no-food control were tested to determine the predators’ development, survivorship, oviposition rate, sex ratio and longevity at 26.5 ± 1°C, 70 ± 5% RH and a 12:12 L:D photophase. Amblyseius largoensis was able to complete its life cycle and reproduce when fed exclusively on R. indica. The development of immature stages of A. largoensis was faster and fecundity and survivorship were higher when fed on R. indica or T. gloveri compared to the other food sources. The intrinsic rate of natural increase of A. largoensis was significantly higher when fed on R. indica than on other diets. These results suggest that, despite earlier assessments, A. largoensis can play a role in controlling R. indica.  相似文献   

12.
Coccodiella is a genus of plant-parasitic species in the family Phyllachoraceae (Phyllachorales, Ascomycota), i.e., tropical tar spot fungi. Members of the genus Coccodiella are tropical in distribution and are host-specific, growing on plant species belonging to nine host plant families. Most of the known species occur on various genera and species of the Melastomataceae in tropical America. In this study, we describe the new species C. calatheae from Panama, growing on Calathea crotalifera (Marantaceae). We obtained ITS, nrLSU, and nrSSU sequence data from this new species and from other freshly collected specimens of five species of Coccodiella on members of Melastomataceae from Ecuador and Panama. Phylogenetic analyses allowed us to confirm the placement of Coccodiella within Phyllachoraceae, as well as the monophyly of the genus. The phylogeny of representative species within the family Phyllachoraceae, including Coccodiella spp., graminicolous species of Phyllachora and taxa with erumpent to superficial stroma from several host families, suggests that the genus Phyllachora might be polyphyletic. Furthermore, tar spot fungi with superficial or erumpent perithecia seem to be restricted to the family Phyllachoraceae, independently of the host plant. We also discuss the biodiversity and host-plant patterns of species of Coccodiella worldwide.  相似文献   

13.
One new genus, two new subgenera, and eight new species from Ecuador, Brazil, and Venezuela are described. The former genus Hattersleya Nischk et Otte is considered as a subgenus of the genus Neoacla Des. Acla multivenosa Chop., A. reticulata Chop., A. vicina Chop., Selvacla choreutes Otte, S. salvator Otte, S. alsiosus Otte, and S. sophos Otte are transferred to the genus Neoacla, and Desutteria epiplatys Nischk et Otte, to the genus Silvastella Des.-Gr. New data on the geographical and ecological distribution of some species are given.  相似文献   

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Psidium acutangulum has been previously understood as a widespread and variable species. Here, it is proposed that populations east of the Andes should be divided into two species: P. acutangulum and P. acidum based on characters of the leaves, anthers, fruits and seeds. The new combination Psidium acidum is made here and the species is described, illustrated and contrasted with P. acutangulum and P. friedrichsthalianum. Psidium acutangulum as now understood remains variable and seems to be related to a mainly Amazonian group of species. Populations from western Ecuador, once thought to belong to P. acutangulum are now considered a new species.  相似文献   

17.
A Gram-stain-positive, polar flagella-containing, rod-shaped, obligate aerobic, endospore-forming bacterium, strain TK1655T, was isolated from the traditional Korean food gochujang. The 16S rRNA sequence of strain TK1655T was a member of the genus Oceanobacillus similar to that of the type strain of Oceanobacillus oncorhynchi subsp. incaldanensis DSM 16557T (97.2%), O. oncorhynchi subsp. oncorhynchi JCM 12661T (97.1%), O. locisalsi KCTC 13253T (97.0%), and O. sojae JCM 15792T (96.9%). Strain TK1655T was oxidase and catalase positive. Colonies were circular, smooth, low convex, cream in colour, and measured about 0.5–1.0 mm in diameter. The range for growth was 20–40°C (optimal, 30°C), pH 6.0–10.0 (optimal, 7.0), and 2–16% (w/v) NaCl (optimal, 2%). Additionally, the cells contained meso-DAP, and the predominant isoprenoid quinone was MK-7. The complex polar lipids were consisted of diphosphatidylglycerol (DPG), phosphatidylglycerol (PG), phosphatidylcholine (PC). The major cellular fatty acid components were iso-C15:0, anteiso-C15:0, iso-C16:0, and anteiso-C17:0, and the DNA G+C content was 40.5%. DNA-DNA relatedness of our novel strain and reference strain O. locisalsi KCTC 13253T, O. oncorhynchi subsp. incaldanensis DSM 16557T, O. oncorhynchi subsp. oncorhynchi JCM 12661T was 45.7, 43.8, and 41.9%. From the results of phenotypic, chemotaxonomic, and phylogenetic analyses of strain TK1655T, we propose the novel species Oceanobacillus gochujangensis sp. nov. The type strain is TK1655T (=KCCM 101304T =KCTC 33014T =CIP 110582T =NBRC 109637T).  相似文献   

18.
The merkli group of the weevil genus Plinthus is revised. Plinthus navarsati Davidian et Savitsky, sp. n. is described from Northeastern Turkey. New data on the morphology and geographical distribution of P. merkli Frivaldszki, 1894, P. cavazzutii Meregalli, 1985, and P. latipennis Meregalli, 1985 are given, with a key to all the four species of the merkli group.  相似文献   

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We describe a new species native to Ecuador and Peru, Miconia complanata . This species has been collected from two different localities: Parque Nacional Podocarpus (Ecuador) and Cordillera del Cóndor (Ecuador and Peru). The strongly quadrangular to winged stem, ridged nodes and coriaceous leaves make this species distinctive even within a large genus.  相似文献   

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