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1.
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Although stream-dwelling gudgeons (Cyprinidae, genus: Gobio) are widespread in Central Europe, the taxonomy of this group and the distribution of its species are still unexplored in detail. The aims of our study are to ascertain taxonomic composition and distribution of the former Gobio gobio superspecies in the inner area of the Carpathian Basin. Since the presence of cryptic species is suspected in this area, we examined the taxonomic and phylogenetic relationships of Central European Gobio taxa by sequencing the mitochondrial DNA control region (mtCR). Additionally, we characterized the genetic structure of 27 stream-dwelling gudgeon populations of this area by Amplified Fragment Length Polymorphism (AFLP). Results of mtCR analysis proved the presence of three species already known as G. obtusirostris (dominant in NW-Hungary), G. gobio (sporadic) and G. carpathicus (sporadic). Additionally, the analysis revealed the existence of one doubtful taxon, G. sp1 (dominant in NE-Hungary), and a new isolated haplogroup (dominant in SW-Hungary). Although Network analysis showed significant detachment among haplogroups, their genetic distances were quite small. Therefore Bayesian phylogenetic analysis showed weak nodal support for the branching pattern both for newly described haplotypes, and for the already accepted species. AFLP data showed distinct population structure and a clear pattern of isolation was revealed by distance of stocks. At the same time, level of separation was not affected by the altitudinal position of sites. Moreover we found three major clusters of populations which were separated according to hydrographic regions, and corresponded to the findings of mtCR analysis. Our results suggest the on-going speciation of gudgeons in the Carpathian Basin, however the separation of haplogroups seems to only be an intermediate phase. The discovered natural pattern seems to be only slightly influenced by anthropogenic impacts. Additionally our results put into question the suitability of the recently accepted within Gobio genus taxonomy.  相似文献   

3.
The relationship between forest succession and microfungal diversity has been poorly studied. Fungi provide important ecosystem services that may deteriorate in deforested or highly disturbed forests. To determine the possible effects of deforestation and forest succession on microfungi, species diversity of hypocrealean fungi (Ascomycota) was compared in forest stands in Eastern Costa Rica representing three stages of succession: 1–2, 25–27 yr old, and an old growth forest. Species diversity in a second‐growth forest fragment surrounded by timber plantations and second‐growth forest was also compared to that of a stand surrounded by old growth forest. The results show that the overall diversity of hypocrealean fungi was inversely proportional to the age of the forest stand, and each family showed different successional trends. Clavicipitaceae was more diverse in the old‐growth forest and was positively related to the age of the forest stand. Nectriaceae was highly diverse in the 1‐ to 2‐yr‐old stand and less diverse in the old‐growth stand. Saprobic and plant pathogenic fungal species were more diverse in the 1‐ to 2‐yr‐old stand and their diversity was inversely proportional to the age of the forest stand. The diversity of insect pathogens was positively related to the age of the forest stand. The 20‐ to 22‐yr‐old forest fragment had the lowest number of species overall. Based on the data gathered in this study, hypocrealean fungal species diversity is related to the successional stage and fragmentation of tropical forest.  相似文献   

4.
Tricholoma scalpturatum is an ectomycorrhizal fungus that forms symbioses with roots of diverse trees and shrubs. It is commonly encountered in a wide range of habitats, across temperate ecosystems. A previous study has revealed a high genetic diversity at a local scale, and ruderal abilities. To examine genetic structure at a large geographical scale, a total of 164 basidiocarps were collected from 30 populations located in Western Europe, from Spain to Scandinavia. These samples were analyzed by three molecular methods with different levels of resolution: inter-simple sequence repeats (ISSRs), restriction fragment length polymorphisms (RFLPs) in the rDNA internal transcribed spacer (ITS), and ITS sequence analysis. Considerable genetic variation was found, and the morphospecies was separated into two genetic groups that were distinct from each other. The ISSR data and the relatively low percentage value (96%) of shared sequence polymorphisms in the ITS between isolates from the two groups, strongly suggest cryptic species and long-lasting separation. No geographical exclusion was detected for these two widely distributed taxa. However, high estimates of population differentiation were observed in each group, including between populations less than a few kilometers apart. This result provides evidence for limited gene flow and/or founding effects. It also indicates that T. scalpturatum does not constitute a random mating population, and the hypothesis of endemism cannot be excluded for this cosmopolitan wind-dispersed fungus.  相似文献   

5.
Posada F  Vega FE 《Mycologia》2005,97(6):1195-1200
The fungal entomopathogen Beauveria bassiana became established as an endophyte in in vitro-grown cocoa seedlings tested for up to 2 mo after inoculation to the radicle with B. bassiana suspensions. The fungus was recovered in culture from stems, leaves and roots. B. bassiana also was detected as an epiphyte 1 and 2 mo postinoculation. Penicillium oxalicum and five bacterial morphospecies also were detected, indicating that these were present as endophytes in the seed.  相似文献   

6.
对nrDNA大亚基部分序列进行序列分析,探讨丛赤壳科11个属的属间关系。研究结果表明,Cosmospora不是单起源,它的成员分别与Nectria,Haematonectria以及Neocosmospora3个不同的属聚类在一起;Haematonectria和Neocosmospora的亲缘关系最接近;Lanatonectria为一个独立的属;以Neonectriadiscophoravar.discophora为代表的Neonectria是一个可靠的属。  相似文献   

7.
Cryptic species continue to be uncovered in many fish taxa, posing challenges for fisheries conservation and management. In Sardinella gibbosa, previous investigations revealed subtle intra-species variations, resulting in numerous synonyms and a controversial taxonomy for this sardine. Here, we tested for cryptic diversity within S. gibbosa using genetic data from two mitochondrial and one nuclear gene regions of 248 individuals of S. gibbosa, collected from eight locations across the Philippine archipelago. Deep genetic divergence and subsequent clustering was consistent across both mitochondrial and nuclear markers. Clade distribution is geographically limited: Clade 1 is widely distributed in the central Philippines, while Clade 2 is limited to the northernmost sampling site. In addition, morphometric analyses revealed a unique head shape that characterized each genetic clade. Hence, both genetic and morphological evidence strongly suggests a hidden diversity within this common and commercially-important sardine.  相似文献   

8.
Beauveria bassiana, an entomogenous fungus used for the biological control of pest insects, comprises a globally‐distributed species complex of regionally endemic lineages. In order to study the population genetics of B. bassiana, detail species boundaries, conduct ecological studies of natural populations and track fates of experimentally‐released strains, sensitive genetic markers are required. We describe the isolation and characterization of eight microsatellite loci that amplify successfully from strains representative of the phylogenetic diversity in the B. bassiana complex.  相似文献   

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The lettuce aphid, Nasonovia ribisnigri (Mosley), is an economically important pest of lettuce worldwide. The entomopathogenic fungus Beauveria bassiana strain GHA has recently been reported as a potential biocontrol candidate for use against the lettuce aphid. This study provides information on the mortality inflicted by B. bassiana when applied against different life stages of the lettuce aphid under laboratory conditions and how fungus infection affects the aphid fecundity. In addition, temporal changes in persistence of fungus inoculum applied to foliage of young lettuce plants under semi-field conditions was analysed. Immature life stages were generally the least susceptible to fungal infection and the susceptibility of all stages was dose-dependent, with the highest mortality occurring at the highest dose. B. bassiana significantly affected the rate of nymph production by the lettuce aphid, with the highest effect seen when the alatoid fourth instar of N. ribisnigri was inoculated with B. bassiana. The persistence of B. bassiana conidia on lettuce foliage was not influenced by leaf position. Within 5 days, the cumulative percentage decline in the conidial population was 38% which declined further to 92% and 99% on day 11 and 20 post-spraying, respectively. In accordance, the infectivity to second instar lettuce aphid nymphs of B. bassiana conidia deposited on leaves declined according to an exponential decay model predicting an intercept of 0.59 ± 0.03 (S.E), a reduction in aphid mortality at a rate of 11% with each increasing day after fungal application and a fungus half-life of 6.34 ± 0.69 days.  相似文献   

11.
Bark beetles (Coleoptera, Scolytinae) are known to be associated with fungi, particularly species of the orders Ophiostomatales and Microascales. However, very little is known about other ectosymbionts of phloeophagous bark beetles on Pinaceae. In this study, we examined the Geosmithia species associated with eight bark beetle species infesting Picea abies and Pinus sylvestris branches in Poland. Fungi were isolated from 1 731 samples collected from 14 study sites. We identified a total of 653 isolates that were sorted into nine taxa based on their phenotypic similarity and phylogeny of their ITS-LSU regions of rDNA, β-tubulin, elongation factor 1α and the second-largest subunit of the RNA polymerase II gene. They represented nine species without formal names. There were large quantitative and qualitative differences in the composition of Geosmithia communities between P. sylvestris and P. abies trees. The proportion of samples infested with Geosmithia species suggests that this association is more widespread among bark beetles infesting branches of P. sylvestris. In addition, these beetles were vectors of different Geosmithia species compared with than the beetles that colonize P. abies. In mixed-conifer forests, the Geosmithia communities were more diverse and richer than in pure spruce or pine stands, where the insects Pityogenes chalcographus and Pityophthorus pityographus with low host-specificity play a distributing role for various Geosmithia species. Among eight bark beetle species examined, only P. bidentatus, P. pityographus, P. chalcographus and Polygraphus poligraphus acted as effective vectors for Geosmithia species. The following hypothesis emerges from these studies: changes in the composition of ectosymbionts of pine- and spruce-infesting bark beetles in Central Europe run along a gradient of thickness of the wood substrata preferred by insects.  相似文献   

12.
Entomopathogenic fungi are among biocontrol agents being considered for the control of aphids on a variety of crops. Predatory coccinellids, although generalist, are also among important natural enemies that must be conserved for aphid management. Laboratory studies were carried out to investigate the interaction between three vegetable-infesting aphids, Metarhizium anisopliae isolate ICIPE 62 and the coccinellid predator Cheilomenes lunata. At a concentration of 1?×?108?conidial?ml–1, the fungus was found to cause mortality of 7.5% to C. lunata, compared to 2.5% mortality in the control at 10?days post-treatment. Female adult C. lunata to which fungus-infected aphids were offered as prey never accepted them as food source in non-choice bioassays. However, live and dead non-infected aphids were fed upon. In choice bioassay, a total of 1–3 out of 24 infected non-sporulating aphids per species (average of 0.1–0.4 aphids per arena) were consumed by 48?h-starved C. lunata within a period of 60?min, but avoided sporulating cadavers. Foraging adult C. lunata enhanced the spread of conidia of M. anisopliae from infected cadavers to fourth instars Aphis gossypii feeding on okra (0.8–15.0% mortality), Brevicoryne brassicae (3.3–15.0% mortality) and Lipaphis pseudobrassicae (0.8–14.2% mortality) on kale plants. Results of this study demonstrate compatibility between M. anisopliae and C. lunata, and could provide a sustainable strategy for effective management of aphids on crucifers and okra cropping systems.  相似文献   

13.
Clonostachys rosea (Link: Fries) Schroers, Samuels, Seifert, and Gams (Ascomycota: Hypocreales) has been reported as a mycoparasite of fungi and nematodes and as saprobe in soils, but this fungus has not been reported previously to be entomopathogenic. Many species of cicadellid leafhoppers cause economic damage to crops as vectors of plant pathogens. In the present work, we report the first record of C. rosea as an entomopathogenic fungus of two leafhoppers pest, Oncometopia tucumana and Sonesimia grossa (Hemiptera: Cicadellidae), in Argentina and evaluate the pathogenicity of C. rosea against them.  相似文献   

14.
We demonstrate the effectiveness of three inoculation methods (foliar spray, seed immersion and root immersion) in establishing fungal the entomopathogen Beauveria bassiana as an endophyte in tobacco, corn, wheat and soybean. Colonisation of leaves by B. bassiana was assessed 7, 14, 21 and 28 days post-inoculation. There were significant differences (p < 0.001) in endophytic colonisation among the different inoculation techniques.  相似文献   

15.
Horismenus parasitoids are an abundant and understudied group of eulophid wasps found mainly in the New World. Recent surveys based on morphological analyses in Costa Rica have quadrupled the number of named taxa, with more than 400 species described so far. This recent revision suggests that there is still a vast number of unknown species to be identified. As Horismenus wasps have been widely described as parasitoids of insect pests associated with crop plants, it is of high importance to properly establish the extant diversity of the genus, in order to provide biological control practitioners with an exhaustive catalog of putative control agents. In this study, we first collected Horismenus wasps from wild Phaseolus bean seeds in Central Mexico and Arizona to assess the genetic relatedness of three morphologically distinct species with overlapping host and geographical ranges. Sequence data from two nuclear and two mitochondrial gene regions uncovered three cryptic species within each of the three focal species (i.e., H. missouriensis, H. depressus and H. butcheri). The monophyly of each cryptic group is statistically supported (except in two of them represented by one single tip in which monophyly cannot be tested). The phylogenetic reconstruction is discussed with respect to differences between gene regions as well as likely reasons for the differences in variability between species.  相似文献   

16.
The fungal entomopathogen Beauveria bassiana became established as an endophyte in coffee seedlings grown in vitro and inoculated with B. bassiana suspensions in the radicle. The fungus was recovered as an endophyte 30 and 60 days postinoculation, from stems, leaves, and roots, and at 60 days postinoculation one of the isolates was also recovered as an epiphyte. Fusarium sp., Rhodotorula sp., and four bacterial morpho-species were also detected, indicating these were present as endophytes in the seed.  相似文献   

17.
《Journal of Asia》2022,25(1):101878
Long-term and intensive use of synthetic insecticides to control the green peach aphid, Myzus persicae (Homoptera: Aphididae) in agricultural production in the world has resulted in pest resistance and environmental pollution. The aim of the study was to develop an environmentally-friendly and effective mycoinsecticide from a local fungal isolate against M. persicae. According to the results of the screening experiments using 15 isolates (6 × Metarhizium, 5 × Beauveria, 2 × Isaria, 2 × Lecanicillium) at 1 × 107 conidia ml?1 concentrations and the dose–response experiments at 1 × 105 –1 × 109 conidia ml?1 concentrations against M. persicae nymphs, Beauveria bassiana (KTU-24) was identified as the most promising isolate. The strain KTU-24 is also had tolerance to ecological conditions such as temperature, and UV-B. KTU-24 with advantageous and superior properties was used to develop a test mycoinsecticide. Mass production of spores by KTU-24 was conducted out by liquid-state fermentation using liquid medium. Spores harvested from the sporulated biomass were used to develop an oil-based mycoinsecticide, and the product was designated as AFIDISIDAL-OD Bbas-TR61. The product had lethal effect on M. persicae nymphs at a concentration of 1 × 108 conidia ml?1 in leaf-disc (82.5%) and pot (84.33%) experiments in a climate chamber. The oil-based mycoinsecticide developed in this study could be profitable when used in aphid-IPM prgrams by reducing crop loss and synthetic pesticides use.  相似文献   

18.
A survey for entomopathogenic fungi of the Chagas disease vector Triatoma infestans was conducted in two provinces of Argentina from March–December 2003. Field-collected insects that died in the laboratory were individually maintained in moist chamber and incubated at 22 °C. Triatominae adults infected with the fungus Paecilomyces lilacinus were found at El Quebracho (27°34′S–64°31′W), Santiago del Estero province, Argentina, in December 2003. Paecilomyces lilacinus was cultured and isolated from infected insects in SDAY, PYG and MEA media. Pathogenicity tests were conducted and positive results were recorded. The median survival time (MST) of T. infestans exposed to a P. lilacinus conidial suspension was 12.8 days, and 100% mortality occurred at 30 days post-treatment. This is the first record of natural infection caused by P. lilacinus in T. infestans in the world.  相似文献   

19.
The effects of Beauveria bassiana strains on coffee berry borers (CBB), which emerge from infested berries left on soil, and its impact on the infestation of coffee berries on tree branches were evaluated at two Experimental Stations (Naranjal-Caldas and Paraguaicito-Quindio) in the Colombian coffee zone. Using a completely randomized design with 10 repetitions, 50 coffee berries artificially infested with CBB were placed on the base of a coffee tree. Four treatments including B. bassiana strain Bb9205, a mixture of Cenicafé strains (Bb9001, Bb9024 and Bb9119), a commercial formulation of B. bassiana and a control (water) were sprayed with 1×109 conidia per tree. After 30 days, all fungal strains lowered the infestation levels of the coffee berries on the trees at both locations. The mixture of Cenicafé strains decreased the tree infestation between 50 and 30% at both locations. In the berries dissected from each treated tree, insect mortality was about 40% at both locations compared to 15% in the control. B. bassiana strains also decreased the insect population inside the newly infested berries on the trees by 55–75%. The mixture of Cenicafé strains was the most effective for decreasing insect populations. B. bassiana significantly decreased CBB populations that emerged from fallen, infested, coffee berries and reduced future insect generations.  相似文献   

20.
Mosasaurs (Squamata: Mosasauridae) were a highly diverse, globally distributed group of aquatic lizards in the Late Cretaceous (98–66 million years ago) that exhibited a high degree of adaptation to life in water. To date, despite their rich fossil record, the anatomy of complete mosasaur sclerotic rings, embedded in the sclera of the eyeball, has not been thoroughly investigated. We here describe and compare sclerotic rings of four mosasaur genera, Tylosaurus, Platecarpus, Clidastes, and Mosasaurus, for the first time. Two specimens of Tylosaurus and Platecarpus share an exact scleral ossicle arrangement, excepting the missing portion in the specimen of Platecarpus. Furthermore, the exact arrangement and the total count of 14 ossicles per ring are shared between Tylosaurus and numerous living terrestrial lizard taxa, pertaining to both Iguania and Scleroglossa. In contrast, two species of Mosasaurus share the identical count of 12 ossicles and the arrangement with each other, while no living lizard taxa share exactly the same arrangement. Such a mosaic distribution of these traits both among squamates globally and among obligatorily aquatic mosasaurs specifically suggests that neither the ossicle count nor their arrangement played major roles in the aquatic adaptation in mosasaur eyes. All the mosasaur sclerotic rings examined consistently exhibit aperture eccentricity and the scleral ossicles with gently convex outer side. Hitherto unknown to any squamate taxa, one specimen of Platecarpus unexpectedly shows a raised, concentric band of roughened surface on the inner surface of the sclerotic ring. It is possible that one or both of these latter features may have related to adaptation towards aquatic vision in mosasaurs, but further quantitative study of extant reptilian clades containing both terrestrial and aquatic taxa is critical and necessary in order to understand possible adaptive significances of such osteological features.  相似文献   

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