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1.
Harmonia axyridis Pallas (1773) (Coleoptera: Coccinellidae) is the well-studied system of invasive insect species. Native and invasive parts of the area of H. axyridis are isolated geographically. We studied the species composition and the distribution of bacterial symbionts Spiroplasma and Rickettsia in seven localities of the native area and six localities of the invasive area of H. axyridis. Rickettsia was detected in H. axyridis populations for the first time. We found that the proportion of beetles infected with Rickettsia in native and invasive populations of H. axyridis is about 0.03. Spiroplasma was found only in native populations of H. axyridis. The proportion of infected individuals with Spiroplasma in native populations of H. axyridis is about 0.08. All studied native populations of H. axyridis are infected with Spiroplasma, while all invasive populations are not. We discuss the possible influence of Spiroplasma and Rickettsia in the formation of invasive populations of H. axyridis.  相似文献   

2.
In the Ross Sea and Amundsen Sea, four representatives of the genus Paralepidapedon—Paralepidapedon cf. dubium Prudhoe et Bray 1973 sensu Sokolov et Gordeev 2013, P. lepidum (Gaevskaya et Rodyuk 1988), Paralepidapedon sp., and P. variabile sp. n.—were found in demersal fishes Muraenolepis marmorata and Macrourus whitsoni. Paralepidapedon variabile sp. n. is described from Muraenolepis marmorata in the Amundsen Sea. Paralepidapedon variabile sp. n. differs from other species of the genus Paralepidapedon by the position of the anterior border of the vitellarium at the level of the anterior edge of the ventral sucker or genital pore and by the highly variable shape of the testes: from roundish with a smooth edge to sinuate–lobate. Paralepidapedon lepidum was found for the first time in the Antarctic.  相似文献   

3.
A comparative analysis of the intestinal microbiomes of some representatives of the Lake Baikal endemic family Comephoridae—the big oilfish Comephorus baicalensis (Pallas, 1776) and the little oilfish C. dybowski (Korotneff, 1904)—has been performed for the first time. The phylotype Akkermansia (phylum Verrucomicrobia) was detected in the C. dybowski microbiome, while Alistipes, Bacteroides, Chryseobacterium, Prevotella (Bacteroidetes), and Peptoniphilus (Firmicutes), were found in the C. baicalensis microbiome. Their presence in the intestine is associated with an elevated lipid uptake or an increase in the human and animal body weight. It is hypothesized that these microorganisms are involved in the lipid metabolism of the oilfish and determine their morphophysiological adaptations to pelagic life.  相似文献   

4.
Dysbiosis, or imbalance in the gut microbiome, has been implicated in auto-immune, inflammatory, neurological diseases as well as in cancers. More recently it has also been shown to be associated with ocular diseases. In the present study, the association of gut microbiome dysbiosis with bacterial Keratitis, an inflammatory eye disease which significantly contributes to corneal blindness, was investigated. Bacterial and fungal gut microbiomes were analysed using fecal samples of healthy controls (HC, n?=?21) and bacterial Keratitis patients (BK, n?=?19). An increase in abundance of several anti-inflammatory organisms including Dialister, Megasphaera, Faecalibacterium, Lachnospira, Ruminococcus and Mitsuokella and members of Firmicutes, Veillonellaceae, Ruminococcaceae and Lachnospiraceae was observed in HC compared to BK patients in the bacterial microbiome. In the fungal microbiome, a decrease in the abundance of Mortierella, Rhizopus, Kluyveromyces, Embellisia and Haematonectria and an increase in the abundance of pathogenic fungi Aspergillus and Malassezia were observed in BK patients compared to HC. In addition, heatmaps, PCoA plots and inferred functional profiles also indicated significant variations between the HC and BK microbiomes, which strongly suggest dysbiosis in the gut microbiome of BK patients. This is the first study demonstrating the association of gut microbiome with the pathophysiology of BK and thus supports the gut–eye axis hypothesis. Considering that Keratitis affects about 1 million people annually across the globe, the data could be the basis for developing alternate strategies for treatment like use of probiotics or fecal transplantation to restore the healthy microbiome as a treatment protocol for Keratitis.  相似文献   

5.
Uveitis (UVT), an inflammatory disease of the eye significantly contributes to vision impairment and blindness. Uveitis is associated with systemic infectious and autoimmune diseases, but in most cases, the aetiology remains unidentified. Dysbiosis in the gut microbiome has been implicated in autoimmune diseases, inflammatory diseases, cancers and mental disorders. In a mice model of autoimmune UVT, it was observed that manipulating the gut microbiome reduces the inflammation and disease severity. Further, alterations in the bacterial gut microbiome and their metabolites were reported in UVT patients from a Chinese cohort. Hence, it is worth comparing the bacterial gut microbiome of UVT patients with that of healthy controls (HC) to ascertain whether dysbiosis of the gut microbiome has implications in UVT. Our analyses showed reduced diversity of several anti-inflammatory organisms including Faecalibacterium, Bacteroides, Lachnospira, Ruminococcus and members of Lachnospiraceae and Ruminococcaceae families, and enrichment of Prevotella (proinflammatory) and Streptococcus (pathogenic) OTUs in UVT microbiomes compared to HC. In addition, decrease in probiotic and antibacterial organisms was observed in UVT compared to HC microbiomes. Heatmap and PCoA plots also indicated significant variations in the microbiomes of UVT versus HC. This is the first study demonstrating dysbiosis in the gut bacterial communities of UVT patients in an Indian cohort and suggests a role of the gut microbiome in the pathophysiology of UVT.  相似文献   

6.

Background and aims

Plant breeding activities shape the rhizosphere microbiome but less is known about the relationship of both with the seed microbiome. We analyzed the composition of bacterial communities of seeds and rhizospheres of Styrian oil pumpkin genotypes in comparison to bulk soil to elucidate specific microbial signatures to support a concept involving plant-microbe interactions in breeding strategies.

Methods

The seed and rhizosphere microbiomes of 14 genotypes of oilseed pumpkin and relatives were analyzed using a 16S rRNA gene amplicon sequencing approach, which was assessed by bioinformatics and statistical methods.

Results

All analyzed microhabitats were characterized by diverse bacterial communities, but the relative proportions of phyla and the overall diversity was different. Seed microbiomes were characterized by the lowest diversity and dominant members of Enterobacteriaceae including potential pathogens (Erwinia, Pectobacterium). Potential plant-beneficial bacteria like Lysobacter, Paenibacillus and Lactococcus contributed to the microbial communities in significant abundances. Interestingly, strong genotype-specific microbiomes were detected for seeds but not for the rhizospheres.

Conclusions

Our study indicates a strong impact of the Cucurbita pepo genotype on the composition of the seed microbiome. This should be considered in breeding of new cultivars that are more capable of exploiting beneficial indigenous microbial communities.
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7.
Mites of the genus Tyrophagus (Acari: Acaridae) are among the most widespread and common mites, inhabiting diverse natural and anthropogenic habitats. Some species are pests of agricultural products and stored food and/or live in house dust, causing allergies to humans. We sequenced 1.2 kb of the mitochondrial COI gene for 38 individuals belonging to seven species of Tyrophagus, including T. curvipenis, T. putrescentiae, T. fanetzhangorum, T. longior, T. perniciosus, and T. cf. similis. Molecular phylogenetic analyses (1) recovered two major clades corresponding to the presence or absence of eyespots, and (2) separated all included morphological species. Tyrophagus curvipenis and T. putrescentiae had the lowest between-species genetic distances (range, mean?±?SD): 14.20–16.30, 15.17?±?0.40 (K2P). The highest within-species variation was found in T. putrescentiae 0.00–4.33, 1.78?±?1.44 (K2P). In this species, we recovered two distinct groups; however, no geographical or ecological dissimilarities were observed between them. Based on our analyses, we document important morphological differences between T. curvipenis and T. putrescentiae. For the first time, we record the occurrence of T. curvipenis in the New World and suggest that it may be an emerging pest as it is currently spreading in agricultural produce.  相似文献   

8.
The rhizosphere microbiome plays a significant role in the life of plants in promoting plant survival under adverse conditions. However, limited information is available about microbial diversity in saline environments. In the current study, we compared the composition of the rhizosphere microbiomes of the halophytes Urochloa, Kochia, Salsola, and Atriplex living in moderate and high salinity environments (Khewra salt mines; Pakistan) with that of the non-halophyte Triticum. Soil microbiomes analysis using pyrosequencing of 16S rRNA gene indicated that Actinobacteria were dominant in saline soil samples whereas Proteobacteria predominated in non-saline soil samples. Firmicutes, Acidobacteria, Bacteriodetes and Thaumarchaeota were predominant phyla in saline and non-saline soils, whereas Cyanobacteria, Verrucomicrobia, Gemmatimonadetes and the unclassified WPS-2 were less abundant. Sequences from Euryarchaeota, Ignavibacteriae, and Nanohaloarchaeota were identified only from the rhizosphere of halophytes. Dominant halophilic bacteria and archaea identified in this study included Agrococcus, Armatimonadetes gp4, Halalkalicoccus, Haloferula and Halobacterium. Our analysis showed that increases in soil salinity correlated with significant differences in the alpha and beta diversity of the microbial communities across saline and non-saline soil samples. Having a complete inventory of the soil bacteria from different saline environments in Pakistan will help in the discovery of potential inoculants for crops growing on salt-affected land.  相似文献   

9.
The species list of fish of the Upper Oka basin is verified. Data on biology of rare species are presented (western brook lamprey Lampetra planeri, sterlet Acipenser ruthenus, bystryanka Alburnoides bipunctatus rossicus, asp Aspius aspius, undermouth Chondrostoma variabile, bitterling Rhodeus sericeus, and fresh-water sculpin Cottus gobio koshewnikowi). Their morphological characters, distribution in the Upper Oka basin relative abundances of these species, and its changes during recent decades are also commented.  相似文献   

10.

Background

Tsetse flies are vectors of African trypanosomes, protozoan parasites that cause sleeping sickness (or human African trypanosomosis) in humans and nagana (or animal African trypanosomosis) in livestock. In addition to trypanosomes, four symbiotic bacteria Wigglesworthia glossinidia, Sodalis glossinidius, Wolbachia, Spiroplasma and one pathogen, the salivary gland hypertrophy virus (SGHV), have been reported in different tsetse species. We evaluated the prevalence and coinfection dynamics between Wolbachia, trypanosomes, and SGHV in four tsetse species (Glossina palpalis gambiensis, G. tachinoides, G. morsitans submorsitans, and G. medicorum) that were collected between 2008 and 2015 from 46 geographical locations in West Africa, i.e. Burkina Faso, Mali, Ghana, Guinea, and Senegal.

Results

The results indicated an overall low prevalence of SGHV and Wolbachia and a high prevalence of trypanosomes in the sampled wild tsetse populations. The prevalence of all three infections varied among tsetse species and sample origin. The highest trypanosome prevalence was found in Glossina tachinoides (61.1%) from Ghana and in Glossina palpalis gambiensis (43.7%) from Senegal. The trypanosome prevalence in the four species from Burkina Faso was lower, i.e. 39.6% in Glossina medicorum, 18.08%; in Glossina morsitans submorsitans, 16.8%; in Glossina tachinoides and 10.5% in Glossina palpalis gambiensis. The trypanosome prevalence in Glossina palpalis gambiensis was lowest in Mali (6.9%) and Guinea (2.2%). The prevalence of SGHV and Wolbachia was very low irrespective of location or tsetse species with an average of 1.7% for SGHV and 1.0% for Wolbachia. In some cases, mixed infections with different trypanosome species were detected. The highest prevalence of coinfection was Trypanosoma vivax and other Trypanosoma species (9.5%) followed by coinfection of T. congolense with other trypanosomes (7.5%). The prevalence of coinfection of T. vivax and T. congolense was (1.0%) and no mixed infection of trypanosomes, SGHV and Wolbachia was detected.

Conclusion

The results indicated a high rate of trypanosome infection in tsetse wild populations in West African countries but lower infection rate of both Wolbachia and SGHV. Double or triple mixed trypanosome infections were found. In addition, mixed trypanosome and SGHV infections existed however no mixed infections of trypanosome and/or SGHV with Wolbachia were found.
  相似文献   

11.
There is increasing concern regarding potential impacts of snake fungal disease (SFD), caused by Ophidiomyces ophiodiicola (Oo), on free-ranging snake populations in the eastern USA. The snake cutaneous microbiome likely serves as the first line of defense against Oo and other pathogens; however, little is known about microbial associations in snakes. The objective of this study was to better define the composition and immune function of the snake cutaneous microbiome. Eight timber rattlesnakes (Crotalus horridus) and four black racers (Coluber constrictor) were captured in Arkansas and Tennessee, with some snakes exhibiting signs of SFD. Oo was detected through real-time qPCR in five snakes. Additional histopathological techniques confirmed a diagnosis of SFD in one racer, the species’ first confirmed case of SFD in Tennessee. Fifty-eight bacterial and five fungal strains were isolated from skin swabs and identified with Sanger sequencing. Non-metric multidimensional scaling and PERMANOVA analyses indicated that the culturable microbiome does not differ between snake species. Fifteen bacterial strains isolated from rattlesnakes and a single strain isolated from a racer inhibited growth of Oo in vitro. Results shed light on the culturable cutaneous microbiome of snakes and probiotic members that may play a role in fighting an emergent disease.  相似文献   

12.
Tuber species produce highly sought-after truffles and host a wide diversity and high abundance of bacteria. It has been suggested that some of these bacteria contribute to the growth, maturity, and aromatic properties of truffles. Here, we characterized and compared the microbiomes of several species of truffles from the Sichuan Province in Southwest China using high-throughput sequencing of bacterial community 16S rRNA genes. Two T. pseudoexcavatum ascocarp samples had relatively similar bacterial communities, as indicated by PCoA analysis. In contrast, three T. indicum samples collected at different maturity stages did not contain similar communities, suggesting that the maturity stage of ascocarps affects community composition in addition to host phylogenetic background. Despite the variation seen among species and maturity stages, the Proteobacteria phylum dominated all communities, which is consistent with previous studies of Tuber-associated bacteria. Moreover, Bradyrhizobium was the dominant genus in most Tuber ascocarps, which is also consistent with previous studies, although the functional role of this genus within truffles is unclear. Notably, Serratia, which are essential producers of thiophene volatiles within T. borchii were dominant in all of our samples. This finding supports the hypothesis that the ability to produce thiophene volatiles is widespread among these bacteria.  相似文献   

13.
14.
Diaphorina citri (Kuwayama) is a global pest of citrus that transmits the bacteria associated with the disease, Huanglongbing. Entomopathogenic fungi and the parasitoid Tamarixia radiata (Waterston) are important biological control agents of this pest and likely to interact in D. citri populations. As a basis for interaction studies, we determined the susceptibility of nymphs and adults of D. citri and adults of the parasitoid T. radiata to six fungal isolates from the species Beauveria bassiana s.l. (Bals.-Criv.) Vuill. (isolates B1 and B3), Metarhizium anisopliae s.s. (Metsch.) (Ma129 and Ma65) and Isaria fumosorosea Wize (I2 and Pae). We conducted experiments evaluating infection levels in all three insect groups following inoculation with a series of conidial concentrations (1 × 104–1 × 108 conidia mL?1). Results showed that D. citri nymphs and T. radiata were more susceptible to fungal isolates than D. citri adults. Overall, B. bassiana and M. anisopliae isolates caused the greatest infection compared with I. fumosorosea isolates in all three groups of insects. Isolates B1 (B. bassiana) and Ma129 (M. anisopliae) infected a greater proportion of adults and nymphs of D. citri, respectively. Both isolates of B. bassiana caused greater infection in T. radiata compared with isolates of the other fungal species. We propose that isolates B1 and Ma129 are the strongest candidates for control of D. citri. Our results represent the first report of entomopathogenic fungi infecting T. radiata, and the basis for future studies to design a biological control programme that uses both agents more efficiently against D. citri populations.  相似文献   

15.
Some species of spider mites belonging to the Tetranychidae family are known to associate with oil palm (Elaeis guineensis Jacq. – Arecaceae). The occurrence of Tetranychus palmarum Flechtmann & Noronha (Acari, Tetranychidae) was verified on oil palm seedlings under greenhouse conditions in the State of Pará in Northern Brazil. Plants with colonies of T. palmarum presented yellowish spots on leaflets and leaves with chlorosis. The objective of this study was to access the biology and fertility life table of T. palmarum in E. guineensis leaves. The experiment was conducted under four constant temperatures, 22, 25, 28, and 31°C, at 70 ± 10% RH under a 12:12 LD photoperiod. The duration of the egg-to-adult period was 18.4 and 9.8 days, at 22 and 31°C, respectively. The parameters of the fertility life table showed that 28°C is most suitable for the development and reproduction of T. palmarum, with higher values for reproductive parameters (R o , r m , and λ) and lower values for duplicating the population (TD). Therefore, it is apparent that the best temperature conditions for the development of T. palmarum are found in the warmer regions of Brazil, such as those observed in northern Brazil.  相似文献   

16.
The tomato leaf miner, Tuta absoluta (Meyrick), is a devastating pest of tomato worldwide. One of the control measures of T. absoluta is the use of biological control agents, such as Trichogramma wasps. Interactions between natural enemies and insect pests may be affected by application of fertilizers, because changes in plant quality through the fertilizer application may therefore affect herbivore characteristics and suitability of them to parasitism. Laboratory tests were carried out to evaluate the life table parameters of Trichogramma brassicae Bezdenko on T. absoluta eggs reared on tomato plants treated either with vermicompost (40%), humic fertilizer (2 g/kg soil), or control (suitable mixture of field soil and sand). Population growth parameters of T. brassicae were affected by fertilizer treatments. Significant differences were found for immature life period and total fecundity of T. brassicae on the treatments. Differences of intrinsic rate of natural increase (r m), finite rate of increase (λ), net reproductive rate (R 0), mean generation time (T), and doubling time (DT) of T. brassicae among treatments were also significant. The lowest values of r m, λ, and R 0 were recorded for T. brassicae developed on T. absoluta eggs on control treatment, whereas the highest values of these parameters were observed on 2 g/kg humic fertilizer. Furthermore, T. brassicae had the shortest T and DT values on 2 g/kg humic fertilizer and 40% vermicompost treatments. Our results showed that application of humic fertilizer and vermicompost could positively affect population growth parameters of T. brassicae on eggs of T. absoluta fed on tomato plants.  相似文献   

17.
Several species of predatory mites, especially those of the family Phytoseiidae, are potentially useful for the control of pest mites and insects. Among the phytoseiids, Euseius concordis (Chant), a species commonly found in South America, has been studied for possible use as biological control agent of pest mites. Given that Euseius species are known to feed on plant leaves and on pollen, the objective of this study was to determine plant species and pollen sources suitable to establish a pilot method of production of that species, based on a set of comparisons in the laboratory. Out of four plant species evaluated in the study, higher survivorship of E. concordis females in the absence of supplementary food was observed on leaflets of Canavalia ensiformis L. Out of two pollen types, higher survivorship was obtained on pollen of Typha domingensis L. In a subsequent step, the population of E. concordis increased 19.3× within 21 days when that pollen of T. domingensis was offered to the predator on plantlets of C. ensiformis, at 25.0 ± 1 °C, 70.0 ± 10% RH and 12 h photophase. Future studies may confirm the economic viability of this setup for the mass production of E. concordis.  相似文献   

18.
The use of Diadegma mollipla (Holmgren) as a biocontrol agent for diamondback moth (DBM)—a notorious pest of crucifers—can potentially be improved with increased scientific knowledge of the D. mollipla’s life history. This study investigated the influence of temperature on the life history traits of D. mollipla parasitizing DBM under laboratory conditions with 20 female D. mollipla for each of five constant temperatures i.e., 15, 20, 25, 30 and 35 °C. Data analysis using curvilinear regression models showed that D. mollipla’s highest intrinsic and finite rates of population increase, net reproductive rate, survival of immatures, daily fertility, shortest immature development and doubling times were achieved between 26 and 30 °C. Thus the results of this study provide evidence to that D. mollipla does not thrive well outside the 26–30 °C temperature range. These results provide baseline information for guiding the use of D. mollipla in the biological control of the destructive DBM pest.  相似文献   

19.
Truffles are the fruiting structures of ascomycetes in the genus Tuber. Because of their economic importance, truffles have been cultivated for many years using artificially inoculated host plants. Nevertheless, the life cycle and reproductive mode of Tuber spp. are still poorly understood. In filamentous ascomycetes, sexual reproduction is genetically controlled by the mating-type (MAT) locus. Among Tuber spp., the MAT locus has been recently characterized in the black truffles Tuber melanosporum and Tuber indicum. Here, by using sequence information derived from these species and from a Tuber borchii expressed sequence tag (EST) showing similarity to the mat1 gene of Alternaria brassicicola, we embarked on a chromosome-walking procedure to sequence the complete MAT region of T. borchii. This fungus produces highly commercialized whitish truffles and represents a model species for addressing basic questions concerning the life cycle of Tuber spp. We show that T. borchii is heterothallic, as its MAT locus is organized into two idiomorphs, each harbored by different mycelial strains. The alignment of the MAT locus from black truffles and T. borchii reveals that extensive sequence rearrangements and inversions occurred between these species. Moreover, by coupling mating-type analyses to karyological observation, we show that mycelia isolated from ascocarps and mycorrhizae are formed by homokaryotic hyphae.  相似文献   

20.
Trichogramma species are important natural enemies of Anticarsia gemmatalis Hübner, a key pest of soybean in new world agroecosystems. Development, longevity and parasitism rate of Trichogramma pretiosum Riley, Trichogramma acacioi Brun, Moraes and Soares and Trichogramma rojasi Nagaraja and Nagarkatti were investigated under natural conditions throughout fall and winter in order to determine how these parasitoids survive during the soybean off-season in southern Brazil. All species remained active along the experimental period. Over 90 % of the parasitoids emerged throughout the off-season, except for T. rojasi which showed lower percentage of emergence in April and May. The reproductive activity was not interrupted during fall and winter, indicating that the parasitoids depend on alternative hosts to survive. Parasitoids survived during the off-season combining slow developmental rate with an increase in adult life span, an important adaptation that improves their chances of finding alternative hosts and food sources.  相似文献   

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