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1.
Phylogenetic analyses of a combined DNA data matrix containing ITS, LSU, rpb2 and tub2 sequences of representative Xylariales revealed that the genus Barrmaelia is a well-defined monophylum, as based on four of its described species (B. macrospora, B. moravica, B. oxyacanthae, B. rhamnicola) and the new species B. rappazii. The generic type of Entosordaria, E. perfidiosa, is revealed as the closest relative of Barrmaelia, being phylogenetically distant from the generic type of Clypeosphaeria, C. mamillana, which belongs to Xylariaceae sensu stricto. Entosordaria and Barrmaelia are highly supported and form a distinct lineage, which is recognised as the new family Barrmaeliaceae. The new species E. quercina is described. Barrmaelia macrospora, B. moravica and B. rhamnicola are epitypified and E. perfidiosa is lecto- and epitypified. Published sequences of Anthostomella and several Anthostomella-like species from the genera Alloanthostomella, Anthostomelloides, Neoanthostomella, Pseudoanthostomella and Pyriformiascoma are evaluated, demonstrating the necessity of critical inspection of published sequence data before inclusion in phylogenies. Verified isolates of several species from these genera should be re-sequenced to affirm their phylogenetic affinities. In addition, the generic type of Anthostomella should be sequenced before additional generic re-arrangements are proposed.  相似文献   

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Elaphoglossum mickeliorum, a new species from the eastern slopes of the Peruvian Andes, is here described and illustrated. It belongs to E. sect. Polytrichia, which is characterized by the presence of subulate scales and absence of hydathodes on the sterile leaves of adult sporophytes. Herbarium specimens of this new species were first collected by Alwyn H. Gentry ca. 40 years ago, but these got readily confused with E. erinaceum and went undescribed since then. The new species differs from members of the E. erinaceum complex by having a nearly continuous band of planar, nonsubulate scales along the laminar margins of sterile leaves. Based on this character, E. mickeliorum resembles species such as E. glaziovii, E. ornatum, and E. scolopendrifolium. It differs from these by the presence of minute glandular hairs on petioles and costae. A distribution map and a figure with line drawings are also provided. For comparative purposes, the line drawing includes E. blepharoglottis, which is here illustrated for the first time.  相似文献   

4.
Specialized natural enemies that forage for polyphagous hosts need to locate hosts on different plants. Telenomus podisi (Hymenoptera: Platygastridae) is a stink bug egg parasitoid with a preference for Euschistus heros (Hemiptera, Pentatomidae), a polyphagous species. The aim of this study was to evaluate the induction of defences in three E. heros host plants: maize (Zea mays), sunflower (Helianthus annuus) and pigeon pea (Cajanus cajan). We hypothesized that E. heros damage to these three plants enhances the attraction of the parasitoid T. podisi as has been observed in other systems. Using Y-tube olfactometer bioassays, we tested parasitoid responses to combinations of the following odour sources: clean air, undamaged plants and plants damaged by stink bug feeding. Volatiles were collected by means of dynamic headspace collection and analysed by gas chromatography coupled to mass spectrometry. T. podisi did not distinguish odours from undamaged plants against air for any of the three plant species. For maize, the parasitoid preferred the odour from herbivore-damaged plants over both clean air and undamaged plants. For sunflower, the parasitoid only preferred the odour of herbivore-damaged plants over the odour of undamaged plants. For pigeon pea, no preferences were observed. Quantitative differences in the volatile profile of damaged and undamaged plants were observed in each plant species. We conclude that sunflower and maize plants, when damaged by E. heros, release volatiles that attract the parasitoid T. podisi; the parasitoid appears to use a different blend composition to distinguish herbivore-damaged plants of each species.  相似文献   

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The ultimate determinants of cathemerality, i.e., activity spread over the 24-h cycle, in primates have been linked to various ecological factors. Owing to the fast rate of habitat modification, it is imperative to know whether and how this behavioral flexibility responds to anthropogenic disturbance. The true lemurs (Eulemur clade) constitute a valuable case to study these potential effects, as all species studied so far exhibit cathemerality. Here we explored the effects of anthropogenic disturbance on activity patterns of Eulemur while controlling for ecological factors proposed as determinants of activity shifts. We first performed a meta-analysis using 13 long-term studies conducted over the last three decades on various populations of Eulemur. We fitted a beta regression using the proportion of diurnality (the activity taking place between sunrise and sunset) as the response variable and seven climatic, ecological, and anthropogenic disturbance variables at each site as predictors. We also present a validation with original data using year-round, 24-h activity of collared brown lemurs (Eulemur collaris) in forest fragments with different levels of disturbance in southeastern Madagascar. Diurnality was prevalent at most sites. Seasonality, proportions of leaves in the diet, and group size were all found to be significant predictors of the proportion of diurnal activity. After controlling for socioecological factors in the model, overall anthropogenic disturbance emerged as a negative predictor of diurnality. Our validation suggests that the lemurs in the more disturbed area exhibited more nocturnal activity than those in the less disturbed area. It is unclear whether the plasticity observed might allow populations of Eulemur to persist in disturbed areas longer than lemurs with less flexible activity patterns.  相似文献   

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Twenty four rhizobial strains were isolated from root nodules of Melilotus, Medicago and Trigonella plants growing wild in soils throughout Egypt. The nearly complete 16S rRNA gene sequence from each strain showed that 12 strains (50 %) were closely related to the Ensifer meliloti LMG6133T type strain with identity values higher than 99.0 %, that 9 (37.5 %) strains were more than 99 % identical to the E. medicae WSM419T type strain, and that 3 (12.5 %) strains showed 100 % identity with the type strain of N. huautlense S02T. Accordingly, the diversity of rhizobial strains nodulating wild Melilotus, Medicago and Trigonella species in Egypt is marked by predominance of two genetic types, E. meliloti and E. medicae, although the frequency of isolation was slightly higher in E. meliloti. Sequencing of the symbiotic nodC gene from selected Medicago and Melilotus strains revealed that they were all similar to those of the E. meliloti LMG6133T and E. medicae WSM419T type strains, respectively. Similarly, nodC sequences of strains identified as members of the genus Neorhizobium were more than 99 % identical to that of N. galegae symbiovar officinalis HAMBI 114.  相似文献   

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Three species of cecidomyiid midges (Diptera: Cecidomyiidae), whose larvae overwinter in the soil, can cause significant yield losses on wheat in Europe: the orange wheat blossom midge, Sitodiplosis mosellana (Géhin), the yellow wheat blossom midge, Contarinia tritici (Kirby), and the saddle gall midge, Haplodiplosis marginata (von Roser). The biological control of wheat midges by their parasitoids can contribute to reduce the midge populations. Soil samples were collected in several fields in Belgium in 2012–2014 in order to characterize the parasitism rates and parasitoid complexes in overwintering larvae. The parasitism rates varied greatly between the sampled fields: 3–100, 0–100 and 2% for S. mosellana, H. marginata and C. tritici, respectively. The parasitism rate was not related to the larval density of wheat midge. The three wheat midges have totally distinct parasitoid complexes in Belgium. Eight species (Hymenoptera: Pteromalidae and Platygastridae) were found as parasitoid of S. mosellana: Macroglenes penetrans (Kirby), Amblypasis tritici (Walker), Euxestonotus error (Fitch), Euxestonutus sp. Fouts, Leptacis sp. Foerster, Platygaster gracilipes (Huggert), Platygaster nisus Walker, and Platygaster tuberosula (Kieffer). According to their abundance, M. penetrans, E. error and P. tuberosula appeared as the main parasitoids of S. mosellana in Belgium. For the two other wheat midges, only one species of the family Platygastridae was found for each midge: Platygaster equestris (Spittler) for H. marginata and Synopeas myles (Walker) for C. tritici.  相似文献   

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The tree-of-heaven Ailanthus altissima (family Simaroubaceae, order Sapindales) is one of the most invasive neophytes in Europe. The tree originated in China and became invasive worldwide in areas with Mediterranean to temperate climates. As known from other invasive plants, only a few pathogens have been reported from A. altissima in Europe, and, to date, powdery mildews on it have been unknown in the European region. Recently, two powdery mildews were found on A. altissima during a survey of neomycetes on non-native plants in Switzerland. Because they did not fit with any of the species known to occur on Simaroubaceae in Asia, they were identified by DNA barcoding using sequences of the ITS region of the n-rDNA, revealing them to be the powdery mildews of plane and oak trees, Erysiphe platani and E. alphitoides. This is the first record of E. platani on a host outside the genus Platanus and its family Platanaceae, as well as its order Proteales. In contrast, E. alphitoides has been reported to occur on several host families and orders. Host jumps over great phylogenetic distances—such as across plant families and orders—appear to be quite common in biogeographically novel associations between Erysiphales species and plants. The consequences of such host jumps for identity and taxonomic placement of species are discussed here. It is further questioned whether both pathogens are usable as biological control agents against the tree-of-heaven.  相似文献   

10.
SnRK2s are a large family of plant-specific protein kinases, which play important roles in multiple abiotic stress responses in various plant species. But the family in Gossypium has not been well studied. Here, we identified 13, 10, and 13 members of the SnRK2 family from Gossypium raimondii, Gossypium arboreum, and Gossypium hirsutum, respectively, and analyzed the locations of SnRK2 homologs in chromosomes based on genome data of cotton species. Phylogenetic tree analysis of SnRK2 proteins showed that these families were classified into three groups. All SnRK2 genes were comprised of nine exons and eight introns, and the exon distributions and the intron phase of homolog genes among different cotton species were analogous. Moreover, GhSnRK2.6 was overexpressed in Arabidopsis and upland cotton, respectively. Under salt treatment, overexpressed Arabidopsis could maintain higher biomass accumulation than wild-type plants, and GhSnRK2.6 overexpression in cotton exhibited higher germination rate than the control. So, the gene GhSnRK2.6 could be utilized in cotton breeding for salt tolerance.  相似文献   

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Ulleung Island is an oceanic volcanic island in Korea, which has never been connected to the adjacent continent. Previous studies highlighted Ulleung Island as an excellent system to study the pattern and process of early stages of flowering plant evolutions on oceanic island. The predominant mode of speciation in flowering plants on Ulleung Island appears to be anagenesis. However, the potentially important role of hybrid speciation among incompletely reproductively isolated lineages cannot be ruled out. Viola woosanensis (Violaceae) is of purportedly hybrid origin between V. ulleungdoensis (i.e., formerly recognized as V. selkirkii in Ulleung Island) and V. chaerophylloides, based on morphology. To examine the origin of V. woosanensis, we sampled a total of 80 accessions, including V. woosanensis and its putative parental species and sequenced nrDNA ITS, and four highly variable chloroplast noncoding regions (trnL-trnF, rpl16 intron, atpF-atpH, and psbA-trnH). Representative species of Viola from Korea were also included in the phylogenetic analyses (maximum parsimony, maximum likelihood, and Bayesian inference). Additive polymorphic sites in the nrDNA ITS regions were confirmed by cloning amplicons from representative species. The molecular data strongly supported the hybrid origin of V. woosanensis, and the maternal and paternal parent were determined to be V. ulleungdoensis and V. chaerophylloides, respectively. The presence of two parental ribotypes in V. woosanensis (with the exception in one population) was confirmed by cloning, suggesting V. woosanensis is primarily the F1 generation. No trace of backcrossing and introgression with its parents was detected due to low fertility of hybrid species. We found a multiple and unidirectional hybrid origin of V. woosanensis. Additional studies are required to determine which factors contribute to asymmetric gene flow of Viola species in Ulleung Island.  相似文献   

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The common weed Euphorbia hirta (Euphorbiaceae) grows widely across tropical and subtropical regions. In this study, plants infected by an Uromyces species displayed characteristic rust pustules delimited by a necrotic band with a reddish-brown border. Observation of leaf tissues revealed 74% of lesions encircled by a row of dark brown setose acervuli, present exclusively within the necrotic area. Acervuli were never observed in the absence of Uromyces pustules. Isolation from healthy leaf tissues revealed the fungus to be endophytic. Morphological and molecular characterization confirmed Uromyces euphorbiae as the pathogen and revealed both the endophyte and the pustule-associated fungus to be members of the Colletotrichum trucatum complex, representing the first record of this fungus on E. hirta. As understanding of the interaction between host plants, endophytes and phytopathogens is currently limited, this system constitutes a model for investigation of the physiological processes involved in this endophyte-biotrophic pathogen interaction.  相似文献   

16.
Pinus massoniana is one of the important afforestation and pioneer tree species, which is widely distribute in southern China. Chloroplast simple sequence repeat markers (cpSSRs) have been widely used in studies of tree genetics, phylogenetic and breeding. We sequenced the whole chloroplast genome sequences of P. massoniana using PCR and Sanger sequencing. A total of 71 cpSSRs were identified, among which mononucleotide repeats were predominant (70.42%). Seventeen primer pairs were developed and amplification tests were conducted with 15 P. massoniana individuals. Also, cross-species amplification tests were conducted among 15 individuals per Pinus species, including P. elliottii, P. bungeana, P. armandii, P. caribaea, P. tabulaeformis, P. taiwanensis and P. yunnanensis which revealed polymorphic information content ranging from 0.2 to 0.8 and average of haploid diversity (h) ranging from 0.29 to 0.63. In addition, the polymorphic cpSSRs were useful in distinguishing the sampled pine species, and could be powerful tool in phylogenetic studies.  相似文献   

17.

Objectives

To improve 1,3-propanediol (1,3-PD) production and reduce byproduct concentration during the fermentation of Klebsiella pneumonia.

Results

Klebsiella. pneumonia 2-1ΔldhA, K. pneumonia 2-1ΔaldH and K. pneumonia 2-1ΔldhaldH mutant strains were obtained through deletion of the ldhA gene encoding lactate dehydrogenase required for lactate synthesis and the aldH gene encoding acetaldehyde dehydrogenase involved in the synthesis of ethanol. After fed-batch fermentation, the production of 1,3-PD from glycerol was enhanced and the concentrations of byproducts were reduced compared with the original strain K. pneumonia 2-1. The maximum yields of 1,3-PD were 85.7, 82.5 and 87.5 g/l in the respective mutant strains.

Conclusion

Deletion of either aldH or ldhA promoted 1,3-PD production in K. pneumonia.
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Herbivore feeding on host plants may induce defense responses of the plant which influence other herbivores and interacting species in the vicinity, such as natural enemies. The present work evaluated the impact of pre-infestation with the tobacco whitefly Bemisia tabaci cryptic species MEAM 1, on the predation ability of the ladybird Propylea japonica, to the green peach aphid Myzus persicae, on tomato plants. The results show that B. tabaci pre-infestation density, duration, and leaf position, can impact prey consumed by P. japonica under various aphid densities. The aphids consumed by P. japonica in each treatment were fit using the Holling type II functional response equation. The predatory efficiency (a/T h) of P. japonica was the highest in the treatment with 60 aphids and 48-h infestation directly on damaged leaves. The predatory efficiencies of P. japonica decreased with a reduction of pre-infestation density and duration. We also observed that pre-infestation on young and undamaged leaves increased predation by P. japonica.  相似文献   

20.
As observed in other self-incompatible species in the Pyrinae subtribe, loquat (Eriobotrya japonica) demonstrates gametophytic self-incompatibility that is controlled by the S-locus, which encodes a polymorphic stylar ribonuclease (S-RNase). This allows the female reproductive organ (style) to recognize and reject the pollen from individuals with the same S-alleles, but allows the pollen from individuals with different S-alleles to effect fertilization. The S-genotype is therefore an important consideration in breeding strategies and orchard management. In an attempt to optimize the selection of parental lines in loquat production, the S-RNase alleles of 35 loquat cultivars and their 26 progeny, as well as five wild loquat species, were identified and characterized in this study. The best pollinizer cultivar combinations were also explored. A total of 28 S-alleles were detected, 21 of which constituted novel S-RNase alleles. The S-haplotypes S2 and S6 were the most frequent, followed by S 29 , S 31 , S 5 , S 24 , S 28 , S 33 , S 34 , S 32 , and S 15 , while the rare alleles S 1 , S 9 , S 14 , S 16 , S 17 , S 18 , S 19 , S 20 , S 21 , S 22 , S 23 , S 27 , and S 35 were only observed in one of the accessions tested. Moreover, the S-genotypes of five wild loquat species (E. prinoides, E. bengalensis, E. prinoides var. dadunensis, E. deflexa, and E. japonica) are reported here for the first time. The results will not only facilitate the selection of suitable pollinators for optimal orchard management, but could also encourage the crossbreeding of wild loquat species to enhance the genetic diversity of loquat cultivars.  相似文献   

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