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1.
Daisuke Kurose Harry C. Evans Djamila H. Djeddour Paul F. Cannon Naruto Furuya Kenichi Tsuchiya 《Mycoscience》2009,50(3):179-189
Native to Japan, Fallopia japonica, most frequently referred to as Japanese knotweed, is a highly problematic invasive weed, particularly in the UK and North
America. During surveys for natural enemies of this plant in Japan, two species of Mycosphaerella were collected. One of these was identified as M. polygoni-cuspidati, and is redescribed and neotypified. Causing a damaging leaf spot disease of F. japonica throughout its natural range in Japan, it is absent from the host’s exotic range. The restriction of M. polygoni-cuspidati to F. japonica in its center of origin, together with its severe impact on host fitness, indicates that this is a coevolved natural enemy
with high potential as a classical biological control agent for the long-term management of this ecologically and economically
important weed. In the field, the fungus has a reduced life cycle, with only spermogonia and pseudothecia (ascomata) being
formed. Ascospores are the primary source of infection, and studies show that the mycelium from in vitro cultures is also
infective and hyphae penetrate mainly via the stomata. A further, undescribed species of Mycosphaerella co-occurs with M. polygoni-cuspidati, here proposed as the new species M. shimabarensis. Both species have been studied using cultural, morphological and molecular phylogenetic methods. 相似文献
2.
Anna G. Aguilera Peter Alpert Jeffrey S. Dukes Robin Harrington 《Biological invasions》2010,12(5):1243-1252
Fallopia japonica (Japanese knotweed) invades riparian areas and roadsides in New England. This large clonal species drastically alters the
appearance of habitats by forming highly productive near-monocultures. To understand how these invasions affect ecosystem
processes in New England, we quantified the impacts of F. japonica on species diversity, primary productivity, and nitrogen cycling at five locations in central Massachusetts, USA. In stands
of F. japonica and in adjacent uninvaded areas, we recorded the cover of each plant species and measured the aboveground biomass and nitrogen
(N) concentrations in plants, along with N retranslocation from F. japonica leaves and several soil characteristics. In addition, we severed rhizomes of peripheral F. japonica shoots to determine if clonal integration contributes to the species’ rapid spread and dominance. Stands of F. japonica had lower species diversity, but greater aboveground biomass and standing N than uninvaded areas. Nitrogen and carbon concentrations
in biomass and N mineralization rates in soil did not differ between stands and adjacent areas. Rhizome severing temporarily
reduced growth of F. japonica, suggesting that retranslocation of photoassimilates and/or nutrients between shoots via rhizomatal connections may maximize
stand level growth rates and facilitate dominance by F. japonica. 相似文献
3.
Joha W. Grobbelaar Z. Wilhelm de Beer Paulette Bloomer Michael J. Wingfield Xu Dong Zhou Brenda D. Wingfield 《Mycoscience》2011,52(2):111-118
Ophiostoma species such as O. quercus are the most frequent causal agents of sapstain of freshly felled hardwood timber and pulpwood. Many species are regarded
as economically important agents of wood degradation. The aim of this study was to identify a collection of Ophiostoma isolates, resembling O. quercus, found on stained Eucalyptus pulpwood chips in China. DNA sequences of the internal transcribed spacer regions, including the 5.8S region, of the ribosomal
DNA, and parts of the β-tubulin and elongation factor-1α genes, revealed that the isolates were not O. quercus. Surprisingly, they represented O. tsotsi, a wound-infesting fungus recently described from hardwoods in Africa. In addition, sequence data from an isolate from agarwood
in Vietnam, identified in a previous study as belonging to an unknown Pesotum species, were also shown to represent O. tsotsi. A high level of genetic variability was observed among isolates of both O. quercus and O. tsotsi. This was unexpected and suggests that both species have been present in Asia for a significant amount of time. 相似文献
4.
Ondřej Koukol 《Mycological Progress》2010,9(3):369-378
Survey of seven strains determined as Septonema ochraceum (Dothideomycetes, inc. sed.) isolated from pine litter or obtained from public collections revealed three new species, Fusicladium cordae, F. sicilianum (Venturiaceae), Cladophialophora matsushimae (Herpotrichiellaceae) and a cryptic species morphologically identical to Devriesia americana (Teratosphaeriaceae), but phylogenetically distinct. Morphological survey and phylogenetic analysis using nucleotide sequence data from the nuclear
ribosomal subunit genes indicate a close relationship within three species colonising pine litter needles, F. cordae, F. pini and F. ramoconidii. F. sicilianum is most related to F. rhodense. C. matsushimae represents a species belonging to one of the lineages of the polyphyletic genus Cladophialophora. None of the strains observed can be classified morphologically as S. ochraceum, of which the type material does not exist. 相似文献
5.
Marcin Sielezniew Izabela Dziekańska Anna M. Stankiewicz-Fiedurek 《Journal of Insect Conservation》2010,14(2):141-149
Phengaris (=Maculinea) arion is an endangered social parasite of Myrmica ants, and for a very long time was considered as specific to Myrmica sabuleti. Previous studies carried out in Poland suggested some discrepancies within this assumption, and therefore a much more intensive
survey was undertaken. The host ant use of P. arion was studied at five sites in different types of biotopes in Poland, i.e. xerothermal grasslands where Thymus pulegioides was used as a larval food plant by the butterfly, and more or less sandy biotopes with Thymus serpyllum. Altogether nine Myrmica species were recorded, and considerable variation in species composition and density of nests was recorded. At four localities
M. sabuleti proved to be the most common ant. A total of 529 Myrmica nests were examined, and only 20 of them contained larvae and pupae of P. arion. Host ants belonged to five different species, i.e. M. sabuleti, Myrmica scabrinodis, Myrmica schencki, Myrmica lobicornis and Myrmica hellenica. Only at one site (NE Poland) was a significant heterogeneity in parasitation rates among Myrmica species detected. M. lobicornis was the most often infested ant there, which may suggest local specialisation of the butterfly. Overall low parasitism rates
may explain the vulnerability of P. arion in Central Europe but further studies are also necessary. 相似文献
6.
S. Kumar Sunil Kumar S. P. Negi J. K. Kanwar 《In vitro cellular & developmental biology. Plant》2008,44(6):474-479
Callus cultures derived from leaf segments of chrysanthemum cultivar ‘Snow Ball’ which was susceptible to Septoria obesa were successfully used for in vitro selection for resistance to this pathogenic fungus. Resistant cell lines were selected by culturing callus on growth medium
containing various concentrations of S. obesa filtrate. Resistant calluses obtained after two cycles (30 d each cycle) of selection were used for plant regeneration. About
30% of the plants regenerated from the resistant calluses and 70–80% of the plants raised from cuttings had acquired considerable
resistance against the pathogen in the field. No phenotypic variation was observed in the selected regenerates. 相似文献
7.
Tainya C. Clarke Kateel G. Shetty Krishnaswamy Jayachandran Michael R. Norland 《BioControl》2007,52(3):399-411
One of the greatest threats to the native ecosystems in any part of the world is the invasion and permanent colonization of
ecosystems by non-native species. Florida is no exception to this biological invasion, and is currently colonized by an extensive
variety of exotic plant species. Originally imported from Asia over 30 years ago, Old World Climbing Fern Lygodium microphyllum (Cavanilles) R. Brown) has become one of the most invasive and destructive weeds in southern Florida. To date different effective
control measures of its growth and spread have not been successful; fire and herbicide applications that are currently employed
are neither cost effective nor environmentally friendly. In light of the highly delicate ecosystem that is being affected
by L. microphyllum, we tested the soil fungus Myrothecium verrucaria (Albertini and Schwein) Ditmar: Fr. for its pathogenicity on the invasive fern. In greenhouse studies the effect of two conidial
concentrations of M. verrucaria on L. microphyllum was investigated. Plants were spray inoculated with M. verrucaria which resulted in successful disease development with leaf necrosis symptoms. The higher conidial concentration (1 × 108 ml−1) produced a disease index of approximately 3 on a scale of 0 to 4, day 24 postinitial inoculation, demonstrating the efficacy
of this fungus as a severe retardant of Lygodium growth. Preliminary screening of selected native plant species for susceptibility to M. verrucaria showed low disease indices after repeated spray inoculations; the highest index attained was 0.4 by Slash pine (Pinus elliottii). 相似文献
8.
Previous studies have demonstrated that the obligate myrmecophytism between Macaranga ant-plants and Crematogaster plant-ants is highly species specific, although multiple Macaranga species can coexist in a microhabitat. However, the species specificity has been described based on the study of trees with
established plant-ant colonies. We studied how the process of settling into the partner Macaranga seedlings by single foundress Crematogaster queens contributes to species specificity. By sampling seedlings of three sympatric Macaranga myrmecophytes species in the field, we tested two hypotheses. The first is that foundresses correctly select their specific
partner plant species when they settle into seedlings. The second hypothesis is that the seasons in which seedlings available
for settling by foundresses appear are segregated among the Macaranga species, and the seasons in which foundress queens settle are synchronized to the appearance of seedlings of specific partner
species; thus species specificity is consequently generated. Our results support the former hypothesis but not the latter:
we always observed foundresses settling species-specific host plants, and seedlings suitable for settling were always available
in each Macaranga species.
Electronic Publication 相似文献
9.
Sheng-Hui Xue Xin-Juan Luo Zhen-Hua Wu Hui-Li Zhang Xin-Yu Wang 《Plant Cell, Tissue and Organ Culture》2008,92(3):251-260
To explore the possibility of an effectively long-term preservation of the germplasm of the HR lines of medicinal plant Astragalus membranaceus, Gentiana macrophylla Pall., and Eruca sativa Mill., both cold storage and cryopreservation approaches were attempted and compared. After 5-month cold storage on half
strength Murashige and Skoog (1962) (1/2 MS) agar medium (AM), up to 82.9, 75.7, and 100% of the A. membranaceus, G. macrophylla and E. sativa hairy roots (HRs) recovered growth, respectively. The survival rates of A. membranaceus and G. macrophylla HRs significantly decreased, whereas that of E. sativa HR was unchanged with the addition of increased levels of exogenous abscisic acid (ABA) during cold storage. Using the encapsulation–vitrification
(EV) method for cryopreservation, the G. macrophylla HRs died, whereas up to 6 and 73% of the A. membranaceus and E. sativa HRs survived, respectively. The HR lines evaluated with both methods showed no significant differences in morphology and
growth rate compared with controls that were not subjected to preservation methods. These results suggest that cold storage
is a more suitable alternative for the HR lines of the three studied plant species and that specificity of plant species have
profound effects on the effectiveness of preservation. 相似文献
10.
The life cycle and developmental stages of Aylax hypecoi (Trotter, 1913, Hymenoptera: Cynipidae: Aylacini) were studied in detail. Aylax hypecoi is known to induce galls in fruits of two Hypecoum species — H. imberbe and H. geslini (Papaveraceae) and the larva develops in host plant fruits. The morphology and development of egg, larva and pupa were investigated, which
has previously not been done. The shape and size of terminal-instar larvae and associated galls are sex-specific. Overwintering
stage, adult emergence and flying periods, and egg productivity were studied also. 相似文献
11.
Members of the genus Rhytidoponera and, to a lesser extent, certain Melophorus spp. are keystone mutualists for the dispersal of seeds in the southwest of Western Australia, with important ramifications
for the ecology and speciation of plants in this biodiversity hotspot. For this reason, it is important to understand the
autecology of the relevant ant species and the way in which they interact with plant seeds. This paper addresses key aspects
of the ecology of three such ant species, Rhytidoponera violacea (Forel), R. inornata Crawley and Melophorus turneri perthensis Wheeler. Data are presented on their geographic distribution, seasonality of foraging, diurnal activity, response to fire,
nest site preference, nest structure, colony size, feeding habits, foraging response to seed availability, and seedling emergence
from nests. The role of all three species as seed dispersers is confirmed, and all three species have ecologies that are well-suited
for dispersal and survival of native plant seeds. Preservation of this interaction is important for the conservation of plants,
and it is fortuitous that all three species are able to survive disturbance and return to rehabilitated areas. However, the
smaller R. inornata, and to a lesser extent, the larger R. violacea, are vulnerable to invasive ant [Pheidole megacephala (Fabricius)] incursions. M. turneri perthensis is able to coexist with the invasive ant unless this is at high densities, probably as a result of its ability to forage
during high temperatures when the invasive species is inactive. 相似文献
12.
Dario Kremer Edith Stabentheiner Želimir Borzan Renata Jurišić Grubešić 《Biologia》2008,63(6):1111-1117
Micromorphological differences in leaves and pollen between two American (Fraxinus americana L., F. pennsylvanica Marshall) and two European (F. angustifolia Vahl, F. excelsior L.) ash species were studied using scanning electron microscope. The types, dimensions and distribution of characteristic
trichomes were established and measured. Capitate hairs on the leaves had the same shape in all researched ash species. Acicular
hairs were regularly present in two American ash species, but very rarely in the glabrous phase of F. angustifolia and F. excelsior. Only F. americana had coronulate abaxial surface of leaves. Pollen of F. angustifolia and F. excelsior had 3 (tricolpate) apertures, and F. americana and F. pennsylvanica 4 (stephanocolpate) apertures. Based on the appearance of the reticulum it’s possible to clearly distinguish all four species.
F. angustifolia and F. pennsylvanica had muri with transversal ridges and seldom granules. Muri of F. excelsior and F. americana had slightly visible transversal ridges, and because of that noticeable granules. 相似文献
13.
We studied the oviposition performance of Fopius arisanus (Sonan) (Hymenoptera: Braconidae) attacking eggs of four fruit flies of the genus Anastrepha Schiner (Diptera: Tephritidae) under laboratory conditions. The complete process of oviposition on an individual egg of Anastrepha ludens (Loew) lasts in average 85.4 ± 2.9 s, including a tremor (25.8 ± 1.03 s) observed in the middle of this process related to
the egg’s descent. The average parasitism of A. ludens egg was 60.9 ± 7.5%, with only 1.2% of superparasitized eggs. During individual acts of oviposition, we noted that F. arisanus possesses a highly flexible ovipositor that curves easily as it searches for additional suitable eggs, which may be of particular
benefit when a female finds large clutches of eggs. The individual oviposition of F. arisanus in host fruits attacked by Anastrepha spp. varies with the egg clutch size of each fruit fly species: A. serpentina laid the biggest egg clutches (21.3 ± 1.4), followed by A. ludens (14.2 ± 0.9), and A. striata (1.0 ± 0.0) (=A. obliqua). The time spent by F. arisanus in individual ovipositions was parallel to these findings, reinforcing the idea that F. arisanus attacks several eggs in each individual insertion of its ovipositor. Neither formal oviposition acts, nor adult emergences
of F. arisanus were registered in A. obliqua. We discuss the potential of F. arisanus as natural enemy of fruit flies of the genus Anastrepha, and explore the eventual developing of its mass rearing.
Handling Editor: Torsten Meiners. 相似文献
14.
Despite species in the Rubus fruticosus complex (wild blackberry) being among the most invasive plants globally in regions with large annual fluctuations in water
availability, little is known about their water relations. We compared water relations of a prominent member of the complex,
R. armeniacus (Himalayan blackberry), with species native to the Pacific Northwest of North America (PNW), R. spectabilis (salmonberry) and R. parviflorus (thimbleberry). In eight stands of each species located near Portland, Oregon, USA, we measured mid-day hydraulic resistance
(R
plant), and daily time series of stomatal conductance (g
s), leaf water potential (Ψlf), and environmental conditions at four time periods spanning the 2007 growing season. Although all species maintained Ψlf above −0.5 MPa in spring, R. armeniacus maintained less negative Ψlf (≥−1.0 MPa) than the natives in summer, a factor attributable to advantages in both its root and shoot systems. R
plant of R. armeniacus was ≤0.1 MPa mmol−1 m2 s for the duration of the study, and approximately 25–50% of R
plant for the native species in summer. R. armeniacus had higher g
s compared to the native species throughout the spring and summer, with approximately twice their rates in summer. Our R
plant and g
s results show that R. armeniacus has access to more water during PNW summers than congeneric natives, allowing it to maintain high water-use, and potentially
helping it achieve higher growth and reproductive rates. Water relations may therefore be a critical component of the competitive
and invasive success of R. armeniacus and other R. fruticosus species worldwide. 相似文献
15.
S. Rehman A. S. Shawl A. Kour R. Andrabi P. Sudan P. Sultan V. Verma G. N. Qazi 《Applied Biochemistry and Microbiology》2008,44(2):203-209
The medicinal plant, Nothapodytes foetida, contains a number of important alkaloids like camptothecin (an anticancer drug molecule), but its concentration is less
to meet the existing demand of this important molecule, in an effort for accessible availability of camptothecin. An endophyte
(designated ZP5SE) was isolated from the seed of Nothapodytes foetida and was examined as a potential source of anticancer drug lead compound, i.e., camptothecin, when grown in Sabouraud liquid
culture media under shake flask conditions. The presence of an anticancer compound (camptothecin) in this fungus was confirmed
by chromatographic and spectroscopic methods in comparison with authentic camptothecin. Isolated endophyte (Neurospora crassa) producing camptothecin may become an easily accessible source for the production of a precursor anticancer drug molecule
in the future at a large scale.
Published in Russian in Prikladnaya Biokhimiya i Mikrobiologiya, 2008, Vol. 44, No. 2, pp. 225–231.
The text was submitted by the authors in English. 相似文献
16.
Prickly acacia, Acacia nilotica subsp. indica (Benth.) Brenan, a major weed of the Mitchell Grass Downs of northern Queensland, Australia, has been the target of biological
control projects since the 1980s. The leaf-feeding caterpillar Cometaster pyrula (Hopffer) was collected from Acacia nilotica subsp. kraussiana (Benth.) Brenan during surveys in South Africa to find suitable biological control agents, recognised as a potential agent,
and shipped into a quarantine facility in Australia. Cometaster pyrula has a life cycle of approximately 2 months during which time the larvae feed voraciously and reach 6 cm in length. Female
moths oviposit a mean of 339 eggs. When presented with cut foliage of 77 plant species, unfed neonates survived for 7 days
on only Acacia nilotica subsp. indica and Acacia nilotica subsp. kraussiana. When unfed neonates were placed on potted plants of 14 plant species, all larvae except those on Acacia nilotica subsp. indica and Acacia nilotica subsp. kraussiana died within 10 days of placement. Cometaster pyrula was considered to be highly host specific and safe to release in Australia. Permission to release C. pyrula in Australia was obtained and the insect was first released in north Queensland in October 2004. The ecoclimatic model CLIMEX
indicated that coastal Queensland was climatically suitable for this insect but that inland areas were only marginally suitable. 相似文献
17.
Luciano Elias Oliveira Kátia G. Facure Ariovaldo A. Giaretta 《Environmental Biology of Fishes》2012,93(1):89-94
We present data on the habitat, density, and spatial distribution of Rivulus giarettai, and discuss some biotic and abiotic variables related to its abundance in Free Flowing Waters (FFW) and Dam Reservoirs (DR)
in palm grove (Mauritia flexuosa) marshes (Veredas) in Uberlandia, Minas Gerais, southeastern Brazil. The mean density (individuals/plot) of R. giarettai was about 13 times higher in FFW than in DR. In FFW, the density of R. giarettai was highest at intermediate amounts of substrate (plant mass) and it was positively rank-correlated with the depth, and the
number of arthropods. Individuals occurred in an aggregated distribution. The aggregated pattern could be related to a concentration
of individuals in microhabitats neither too much exposed nor completely saturated by plants. R. giarettai was relatively abundant and tolerant to slight man-made habitat modifications. Damming appeared to be especially problematic
by negatively affecting its density. 相似文献
18.
Jinwook Seo Suk Weon Kim Jonghyun Kim Hyun Wook Cha Jang R. Liu 《Journal of Plant Biology》2007,50(6):626-631
Theflavonoid 3′,5′-hydroxylase (F3′,5′H) gene, derived from petunia, was introduced into chrysanthemum tissues by Agrobacterium-mediated genetic transformation.
Cotyledon expiants were co-cultured withA. tumefaciens LBA 4404 harboring the vector pMBP that carriesF3′,5′H under the control of the CaMV 35S promoter andnptll as a selectable marker gene. After 72 h of co-cultivation, the expiants were placed on an MS medium supplemented with 4 mg
L-1 BA, 0.1 mg L-1 NAA, 400 mg L-1 carbenicillin, and 100 mg L-1; kanamycin. After 4 weeks, kanamycin-resistant adventitious shoots had developed at a frequency of 6.3%. These shoots were
then rooted and acclimatized in potting soil. Integration ofF3′,5′H into the plant genome was confirmed by Southern blot analysis. Flower buds that had red petals did not differ between the
transgenic and the wild-type plants. However, petal color did change from red to bright orange to yellow when the buds developed
into fully opened flowers on the transgenics. Spectrometric analysis revealed that the content of flavonoid compounds was
more rapidly reduced in the transgenic petals as floral development proceeded. RT-PCR analysis showed thatF3′,5′H andflavonoid 3′hydroxylase (F3′H) were expressed simultaneously in the transgenic plants. Therefore, we suggest that this more rapid change in petal color
results from 1) competition between levels of transgenicF3′,5′H and endogenousF3′H, each of which uses the same substrate in the flavonoid biosynthetic pathway and 2) the intrinsic substrate specificity of
chrysanthemumDFR (dihydroflavonol 4-reductase). 相似文献
19.
Ratul Saha Robert S. Donofrio Susan T. Bagley 《Journal of industrial microbiology & biotechnology》2010,37(8):843-848
A TaqMan quantitative real-time polymerase chain reaction (qPCR) assay was developed for the detection and enumeration of
three Pseudomonas species belonging to the mendocina sublineage (P. oleovorans, P. pseudoalcaligenes, and P. oleovorans subsp. lubricantis) found in contaminated metalworking fluids (MWFs). These microbes are the primary colonizers and serve as indicator organisms
of biodegradation of used MWFs. Molecular techniques such as qPCR are preferred for the detection of these microbes since
they grow poorly on typical growth media such as R2A agar and Pseudomonas isolation agar (PIA). Traditional culturing techniques not only underestimate the actual distribution of these bacteria but
are also time-consuming. The primer–probe pair developed from gyrase B (gyrB) sequences of the targeted bacteria was highly sensitive and specific for the three species. qPCR was performed with both
whole cell and genomic DNA to confirm the specificity and sensitivity of the assay. The sensitivity of the assay was 101 colony forming units (CFU)/ml for whole cell and 13.7 fg with genomic DNA. The primer–probe pair was successful in determining
concentrations from used MWF samples, indicating levels between 2.9 × 103 and 3.9 × 106 CFU/ml. In contrast, the total count of Pseudomonas sp. recovered on PIA was in the range of <1.0 × 101 to 1.4 × 105 CFU/ml for the same samples. Based on these results from the qPCR assay, the designed TaqMan primer–probe pair can be efficiently
used for rapid (within 2 h) determination of the distribution of these species of Pseudomonas in contaminated MWFs. 相似文献
20.
Ewa Dubas Gabriela Golebiowska Iwona Zur Maria Wedzony 《Acta Physiologiae Plantarum》2011,33(2):529-537
According to regular reports, one of the most serious diseases of winter cereal and grass varieties in moderate and cold climatic
areas is pink snow mould caused by Microdochium nivale. Currently, the resistance of the economically important cereal species as triticale is not satisfactory. Moreover, there
is no efficient strategy of protection against this pathogen and the understanding of plant resistance mechanisms is rather
poor. Presented paper for the first time shows the cytological analysis of M. nivale infection in model triticale varieties by the use of fluorescent and light microscopy in combination with fluorescent dyes
and hydrogen peroxide staining. Both, the infection level and the dynamic of the process varied for tested genotypes confirming
the field and laboratory data of their different resistance to this pathogen. Moreover, our analysis showed that in both cultivars
cold-hardening of seedlings delayed the mycelium growth. In both cultivars, hyphal walls and fungal penetration sites were
visualized in crowns, leaf sheaths and leaves of hardened and non-hardened inoculated seedlings. For the first time the presence
of the haustoria produced by M. nivale was confirmed in those tissues. Single infection hyphae usually penetrated into the host tissues via stomatal apparatuses
were accompanied by the efflux of hydrogen peroxide. The data show a great potential of fluorescence techniques in studying
the host plant–pathogen interactions providing a better insight into plant defence reactions that may allow elaboration of
the efficient breeding strategies aimed at increasing resistance to this pathogenic fungus. 相似文献