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The cytoplasmically inherited bacterium Wolbachia is widespread in arthropod species and has been repeatedly detected in the predaceous mite Phytoseiulus persimilis. Our original goal was to assess the prevalence of Wolbachia infection in P. persimilis and the potential fitness consequences for this host. To accomplish that goal, seven P. persimilis strains were obtained from Europe, Africa and the USA and reared on the phytophagous mite Tetranychus urticae as prey. After preliminary results showed that the T. urticae used was infected with Wolbachia, the minimum starvation time of the predators to prevent false positive results from undigested prey was determined. We tested DNA samples by PCR (polymerase chain reaction) after starving the predators or feeding them Wolbachia-free T. urticae for various periods. Those experiments showed that Wolbachia could not be detected after 16 h at 25 °C and 48 h at 20 °C. To verify the results of the PCR analyses, we furthermore conducted crossing experiments with antibiotic-treated and untreated individuals. No indications of Wolbachia effects were recorded. Additionally, we screened live eggs of four of the seven strains reared in our laboratory and alcohol samples of 10 other P. persimilis strains for the occurrence of Wolbachia by PCR, none of which tested positive. Synthesis of our study and previous reports suggests that infection of P. persimilis with Wolbachia is extremely rare and of minor importance. We discuss the significance of our findings for future studies on the presence of Wolbachia in predaceous arthropods. 相似文献
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Raquel Abad-Moyano Alberto Urbaneja Daniela Hoffmann Peter Schausberger 《Experimental & applied acarology》2010,50(4):329-341
The two-spotted spider mite, Tetranychus urticae, is one of the most problematic phytophagous pests in Spanish clementine orchards. The most abundant predatory mites in this
ecosystem are Euseius stipulatus, Phytoseiulus persimilis and Neoseiulus californicus. Euseius stipulatus is dominant but poorly adapted to utilize T. urticae as prey. It mainly persists on pollen and citrus red mite, Panonychus citri. A recent study suggested that the more efficacious T. urticae predators P. persimilis and N. californicus are negatively affected by lethal and non-lethal intraguild interactions with E. stipulatus. Here, we investigated the potential of N. californicus and P. persimilis to colonize and thrive on young clementine trees infested by T. urticae in presence and absence of E. stipulatus. Presence of E. stipulatus interfered with establishment and abundance of P. persimilis and negatively affected the efficacy of N. californicus in T. urticae suppression. In contrast, the abundance of E. stipulatus was not affected by introduction of a second predator. Trait-mediated effects of E. stipulatus changing P. persimilis and N. californicus behavior and/or life history were the most likely explanations for these outcomes. We conclude that superiority of E. stipulatus in intraguild interactions may indeed contribute to the currently observed predator species composition and abundance, rendering
natural control of T. urticae in Spanish clementine orchards unsatisfactory. Nonetheless, stronger reduction of T. urticae and/or plant damage in the predator combination treatments as compared to E. stipulatus alone indicates the possibility to improve T. urticae control via repeated releases of N. californicus and/or P. persimilis. 相似文献
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Raquel Abad-Moyano Tatiana Pina Jordi Pérez-Panadés Emilio A. Carbonell Alberto Urbaneja 《Experimental & applied acarology》2010,50(4):317-328
Tetranychus urticae is one of the most damaging tetranychid mites affecting clementine orchards in Spain, where natural control is insufficient.
Furthermore, in clementine nurseries, tender foliage is highly susceptible to attack and natural enemies are almost always
absent. Therefore, acaricides are often used indiscriminately. Alternative control measures are necessary, both in commercial
orchards and clementine nurseries. In order to assess the efficacy of inoculative releases of N. californicus and P. persimilis to reduce T. urticae populations in young Spanish clementine plants, a semi-field experiment was conducted and repeated in three seasons (spring,
summer and autumn). Phytoseiulus persimilis was highly effective in reducing both T. urticae infestations and the damage level inflicted on plants at both release rates evaluated (40 and 80 phytoseiids/plant) and all
three periods considered. By contrast, N. californicus demonstrated low performance under certain conditions. The results of this study could be adapted and transferred to nurseries
and young citrus plantations. 相似文献
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Park JJ Kim M Lee JH Shin KI Lee SE Kim JG Cho K 《Experimental & applied acarology》2011,54(3):243-259
Laboratory bioassays were conducted to evaluate the sublethal effects of fenpyroximate and pyridaben on life-table parameters
of two predatory mites species, Neoseiulus (= Amblyseius) womersleyi and Phytoseiulus persimilis. In these assays, young adult females were treated with three sublethal concentrations of each acaricide. The life-table
parameters were calculated at each acaricide concentration, and compared using bootstrap procedures. For each acaricide, the
LC50 estimates for both species were similar, yet the two species exhibited completely different susceptibility when the population
growth rate was used as the endpoint. Exposure to both acaricides reduced the net reproduction rate (R
o
) in a concentration-dependent manner and their EC50s were equivalent to less than LC7. Two different scales of population-level endpoints were estimated to compare the total effect between the species and treatments:
the first endpoint values were based on the net reproductive rate (fecundity λ) and the second endpoint values incorporated
the mean egg hatchability into the net reproductive rate (vitality λ). The fecundity λ decreased in a concentration-dependent
manner for both acaricide treatments, but the vitality λ decreased abruptly after treatment of N. womersleyi with pyridaben. The change in the patterns of λ revealed that the acaricide effects at the population level strongly depended
on the life-history characteristics of the predatory mite species and the chemical mode of action. When the total effects
of the two acaricides on N. womersleyi and P. persimilis were considered, fenpyroximate was found to be the most compatible acaricide for the augmentative release of N. womersleyi after treatment. 相似文献
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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 相似文献
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Phylogenetic relations within the genus Gordonia were analyzed using partial gyrB and secA1 gene sequences of 23 type species in comparison with those of 16S rRNA gene. The gyrB and secA1 phylogenies showed agreement with that constructed using 16S rRNA gene sequences. The degrees of divergence of the gyrB and secA1 genes were approximately 3.4 and 1.7 times greater, respectively, than that of 16S rRNA gene. The gyrB gene showed more discriminatory power than either the secA1 or 16S rRNA gene, facilitating clear differentiation of any two Gordonia species using gyrB gene analysis. Our data indicate that gyrB and secA1 gene sequences are useful as markers for phylogenetic study and identification at the species level of the genus Gordonia. 相似文献
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The two-spotted spider mite, Tetranychus urticae Koch, is an important pest of tomato in different parts of the world. Biological control of this pest on this crop has not
been very successful. Phytoseiulus
macropilis (Banks) has been used commercially for the control of T. urticae on different crops, but no information has been published on its potential to control T. urticae on tomato. The objective of this work was to compare the performance of a Brazilian population of P. macropilis on tomato with its performance on other plant species, relating the observed variation to the respective types and densities
of trichomes. It has been hypothesized that the presence of the webbing produced by T. urticae could help the predator to avoid contact with trichomes and consequently to improve its performance on tomato plants. This
hypothesis was also evaluated. Phytoseiulus
longipes Evans was included in the work as a control, given that it has been reported to be a promising predator of Tetranychus species on tomato. The study was conducted under laboratory conditions. It was found that the performance of P. macropilis was similar to that of P. longipes and that trichomes hampered the locomotion as well as prey consumption and oviposition rate of both predators; that the presence
of webbing resulted in higher levels of prey consumption and of predator oviposition; and that the presence of webbing eliminated
the negative effect of trichomes of eggplants and partially eliminated the negative effect of trichomes of the ‘cerasiforme’
tomato variety. The observed density of trichomes in ‘Carmem’ one of the most common tomato varieties grown in Brazil, seems
not to have interfered significantly with the prey consumption and the oviposition rate of P. macropilis. The results suggest that the latter is a promising predator of T. urticae on tomato. Complementary studies are warranted, to further evaluate the potential of P. macropilis for use as a biological control agent of this pest. 相似文献
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Srikulnath K Thongpan A Suputtitada S Apisitwanich S 《Molecular biology reports》2012,39(4):4709-4717
Based on molecular phylogeny of available complete mitochondrial DNA (mtDNA) genome sequences reveals that Crocodylus siamensis and C. porosus are closely related species. Yet, the sequence divergence of their mtDNA showed only a few values under conspecific level.
In this study, a new haplotype (haplotype2, EF581859) of the complete mtDNA genome of Siamese crocodile (C. siamensis) was determined. The genome organization, which appeared to be highly similar to haplotype1 (DQ353946) mtDNA genome of C. siamensis, was 16,814 bp in length. However, the sequence divergence between the two genomes differed by around 7–10 and 0.7–2.1% for
the haplotype1 between C. siamensis and C. porosus (AJ810453). These results were consistent with the phylogenetic relationship among the three genomes, suggesting that C. siamensis haplotype1 mtDNA genome might be the hybrid or the intraspecific variation of C. porosus. On the other hand, our specimen was found to be a true C. siamensis. Simultaneously, the seven species-specific DNA markers designed based on the distinctive site between haplotype2 mtDNA sequences
of C. siamensis and haplotype1 mtDNA sequence of C. siamensis–C. porosus were successfully used to distinguish C. siamensis from C. porosus. These effective markers could be used primarily for rapid and accurate species identification in population, ecology and
conservation studies. 相似文献
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Lucentini Livia Vercillo Francesca Palomba Antonella Panara Fausto Ragni Bernardino 《Conservation Genetics》2007,8(3):757-759
A non-invasive genetic approach has been recently employed in the population genetics of wild species, using faeces that could
be easily collected, particularly of elusive or endangered species. However, faeces of pine (Martes martes) and beech marten (M. foina) can be morphologically similar and could be confused with those of polecat (Mustela putorius) and red fox (Vulpes vulpes). On this basis, a rapid, simple and inexpensive RFLP protocol using a cytochrome b (Cyt b) gene fragment of mtDNA, isolated from faecal samples, was performed to distinguish the above-mentioned species. 相似文献
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A pea rust fungus, Uromyces viciae-fabae, has been classified into two varieties, var. viciae-fabae and var. orobi, based on differences in urediniospore wall thickness and putative host specificity in Japan. In principal component analyses, morphological features of urediniospores and teliospores of 94 rust specimens from Vicia, Lathyrus, and Pisum did not show definite host-specific morphological groups. In molecular analyses, 23 Uromyces specimens from Vicia, Lathyrus, and Pisum formed a single genetic clade based on D1/D2 and ITS regions. Four isolates of U. viciae-fabae from V. cracca and V. unijuga could infect and sporulate on P. sativum. These results suggest that U. viciae-fabae populations on different host plants are not biologically differentiated into groups that can be recognized as varieties.Contribution no. 184, Laboratory of Plant Parasitic Mycology, Institute of Agriculture and Forestry, University of Tsukuba, Japan 相似文献
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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. 相似文献
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This study was conducted to investigate the applicability of rpoB, which encodes the β subunit of RNA polymerase, to be used as an alternative to 16S rRNA gene sequence similarity analysis
in the thermophilic genus Anoxybacillus. Partial rpoB sequences were generated for the 14 type strains of Anoxybacillus species and 6 other strains of four Anoxybacillus species. The sequences and the phylogenetic tree of rpoB were compared with those obtained from 16S rRNA gene analysis. The rpoB gene was found to provide a better resolution for Anoxybacillus species, with lower interspecies sequence similarities. The rpoB sequence similarity analysis permitted a more accurate discrimination of the species within the Anoxybacillus genus than the more commonly used 16S rRNA gene. Furthermore, rapid and reproducible repetitive extragenic palindromic fingerprinting
techniques (REP-, ERIC-, and BOX-PCR) were employed for the specimens of genus Anoxybacillus. Through comparison of the three methods, it was found that the BOX-PCR method generated more informative results than REP-PCR
for the studied strains; BOX-PCR profiles were more distinct for the different strains, including a higher number of bands.
Rapid and reproducible repetitive extragenic palindromic fingerprinting techniques (rep-PCR) constitute a suitable molecular
approach for the validation and maintenance of taxonomy within the Anoxybacillus genus. The results of this study show that rpoB and rep-PCR provide rapid and reliable methods for molecular typing of Anoxybacillus species. 相似文献
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Genetic and geographical differentiation of <Emphasis Type="Italic">Pandaka</Emphasis> gobies in Japan 总被引:1,自引:1,他引:0
The mitochondrial DNA (mtDNA) phylogeny of Japanese Pandaka species (Perciformes: Gobiidae) was inferred from partial nucleotide sequences of the mitochondrial 12S and 16S rRNA genes (1083bp). The resultant mtDNA tree showed two major clades (clade I and clade II), which were inconsistent with the present taxonomic classification. One of the major clades was further divided into two geographical groups, distributed on the Japanese Major Islands (clade I-A) and from Amami-oshima Island to Iriomote Island (clade I-B). The mtDNA haplotypes in clade II were found only on Iriomote Island. The mtDNA divergences in clade I indicated that the Japanese Major Island (clade I-A) and Ryukyu (clade I-B) groups have been geographically isolated from each other for millions of years, based on the putative molecular divergence rate. The geographical distributions of mtDNA haplotypes in clade I-A and clade I-B also suggested that Pandaka gobies had not dispersed to distant offshore islands, indicating that their geographical differentiation may be closely associated with the geological history of the Japanese and Ryukyu Archipelagos.This revised version was published online in January 2005 with corrections to the repetition of the 1st authors name. 相似文献
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Imed Sbissi Mohamed Neffati Abdellatif Boudabous Claude Murat Maher Gtari 《Antonie van Leeuwenhoek》2010,98(4):429-436
The molecular phylogeny and comparative morphological studies reported here provide evidence for the recognition of the genus
Picoa, an hypogeous desert truffle, in the family Pyronemataceae (Ascomycota, Pezizales). Picoa juniperi and Picoa lefebvrei were reassigned to the genus Picoa based on large subunit (LSU) sequence (28S) rDNA and internal transcribed spacer (ITS) rDNA (including the partial 18S, ITS1,
ITS2, 5.8S gene, and partial 28S of the nuclear rDNA) data. Morphological studies of spores, asci, perida, and gleba revealed
high similarities between P. lefebvrei and P. juniperi, thereby confirming the membership of both species in the genus Picoa. These two species were primarily distinguishable based on ascospore ornamentation. 相似文献
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The Lactobacillus plantarum group comprises five very closely related species. Some species of this group are considered to be probiotic and widely applied
in the food industry. In this study, we compared the use of two different molecular markers, the 16S rRNA and dnaK gene, for discriminating phylogenetic relationships amongst L. plantarum strains using sequencing and DNA fingerprinting. The average sequence similarity for the dnaK gene (89.2%) among five type strains was significantly less than that for the 16S rRNA (99.4%). This result demonstrates
that the dnaK gene sequence provided higher resolution than the 16S rRNA and suggests that the dnaK could be used as an additional phylogenetic marker for L. plantarum. Species-specific profiles of the Lactobacillus strains were obtained with RAPD and RFLP methods. Our data indicate that phylogenetic relationships between these strains
are easily resolved using sequencing of the dnaK gene or DNA fingerprinting assays. 相似文献
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Kiyomi Tsutsui Atsushi Suwa Kei’ichi Sawada Toshihide Kato Takeshi A. Ohsawa Yasuyuki Watano 《Journal of plant research》2009,122(5):509-521
Introgression has been considered to be one of main factors leading to phylogenetic incongruence among different datasets
at lower taxonomic levels. In the plants of Pinaceae, the mtDNA, cpDNA, and nuclear DNA (nrDNA) may have different evolutionary
histories through introgression because they are inherited maternally, paternally and biparentally, respectively. We compared
mtDNA, cpDNA, and two low-copy nrDNA phylogenetic trees in the genus Pinus subgenus Strobus, in order to detect unknown past introgression events in this group. nrDNA trees were mostly congruent with the cpDNA tree,
and supported the recent sectional and subsectional classification system. In contrast, mtDNA trees split the members of sect.
Quinquefoliae into two groups that were not observed in the other gene trees. The factors constituting incongruence may be divided into
the following two categories: the different splits within subsect. Strobus, and the non-monophyly of subsect. Gerardianae. The former was hypothesized to have been caused by the past introgression of cpDNA, mtDNA or both between Eurasian and North
American species through Beringia. The latter was likely caused by the chimeric structure of the mtDNA sequence of P. bungeana, which might have originated through past hybridization, or through a horizontal transfer event and subsequent recombination.
Electronic supplementary material The online version of this article (doi:) contains supplementary material, which is available to authorized users. 相似文献