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1.
Trifone D’Addabbo Pinarosa Avato Aldo Tava 《European journal of plant pathology / European Foundation for Plant Pathology》2009,125(1):39-49
The nematicidal effect of soil amendments with dry top and root material from Medicago sativa and/or Medicago arborea was evaluated on the root-knot nematode Meloidogyne incognita and on the cyst nematode Globodera rostochiensis in potting mixes. All amendments suppressed root and soil population densities of both nematode species compared to non-treated
and chemical controls. The suppressiveness of M. sativa differed between top and root material and among the amendment rates. In field conditions soil amendments with 20 or 40 t
ha−1 of a pelleted M. sativa meal increased tomato crop yield and reduced soil population densities and root galling by M. incognita. It is suggested that saponins were at least partly responsible for the nematicidal activity. 相似文献
2.
Fusarium species are soil-borne fungal pathogens that produce a variety of disease symptoms when attacking crop plants. The mode of root colonization of Eucalyptus viminalis seedlings by a pathogenic F. oxyporum strain (Foeu1) at the ultrastructural level and changes in cell wall pectin during host pathogen interactions are described. Root systems of E. viminalis plants were inoculated with F. oxysporum in an in vitro model system. Hyphae of F. oxysporum adhered to the outer epidermal cell walls through fibrillar material, and after penetration they spread into the internal tissues. They developed intercellularly and intracellularly in the root cortex and invaded vascular tissues. Papillae were induced, and the host plasma membrane ruptured in colonized cells, causing rapid host tissue and cell damage. Changes in distribution and occurrence of nonesterified and methyl-esterified pectins were evaluated after root colonization by F. oxysporum using two monoclonal antibodies, JIM 5 and JIM 7, respectively. Nonesterified pectin in control roots was mainly localized in the epidermal cell walls and middle lamellae in parenchymal cortex, whereas methyl-esterified pectin accumulated more in primary cell walls of the cortex and phloem. Decreases in immunodetected nonesterified and methyl-esterified pectins were associated with extensive plant tissue degradation after root colonization by the pathogenic fungus. 相似文献
3.
Nazir Javed Said El-Hassan Simon Gowen Barbara Pemproke Muhammed Inam-ul-Haq 《European journal of plant pathology / European Foundation for Plant Pathology》2008,120(1):53-60
Initial applications of 104 spores g−1 of Pasteuria penetrans, and dried neem cake and leaves at 3 and 2% w:w, respectively, were applied to soil in pots. Juveniles of Meloidogyne javanica were added immediately to the pots (500, 5,000 or 10,000) before planting 6-week-old tomato seedlings. The tomatoes were
sampled after 64 days; subsequently a second crop was grown for 59 days and a third crop for 67 days without further applications
of P. penetrans and neem. There was significantly less root-galling in the P. penetrans combined with neem cake treatment at the end of the third crop and this treatment also had the greatest effect on the growth
of the tomato plants. At the end of the third crop, 30% of the females were infected with P. penetrans in those treatments where spores had been applied at the start of the experiment. The effects of neem leaves and neem cake
on the nematode population did not persist through the crop sequences but the potential for combining the amendments with
a biological control agent such as P. penetrans is worthy of further evaluation. 相似文献
4.
Organic management of soils is generally considered to reduce the incidence and severity of plant diseases caused by soil-borne
pathogens. In this study, take-all severity on roots of barley and wheat, caused by Gaeumannomyces graminis var. tritici, was significantly lower in organically-managed than in conventionally-managed soils. This effect was more pronounced on
roots of barley and wheat plants grown in a sandy soil compared to a loamy organically-managed soil. Fluorescent Pseudomonas spp. and in particular phlD+ pseudomonads, key factors in the take-all decline phenomenon, were represented at lower population densities in organically-managed
soils compared to conventionally-managed soils. Furthermore, organic management adversely affected the initial establishment
of introduced phlD+ P. fluorescens strain Pf32-gfp, but not its survival. In spite of its equal survival rate in organically- and conventionally-managed soils, the efficacy
of biocontrol of take-all disease by introduced strain Pf32-gfp was significantly stronger in conventionally-managed soils than in organically-managed soils. Collectively, these results
suggest that phlD+ Pseudomonas spp. do not play a critical role in the take-all suppressiveness of the soils included in this study. Consequently, the role
of more general mechanisms involved in take-all suppressiveness in the organically-managed soils was investigated. The higher
microbial activity found in the organically-managed sandy soil combined with the significantly lower take-all severity suggest
that microbial activity plays, at least in part, a role in the take-all suppressiveness in the organically-managed sandy soil.
The significantly different bacterial composition, determined by DGGE analysis, in organically-managed sandy soils compared
to the conventionally-managed sandy soils, point to a possible additional role of specific bacterial genera that limit the
growth or activity of the take-all pathogen. 相似文献
5.
G. D. Almeida D. Pratissoli J. C. Zanuncio V. B. Vicentini A. M. Holtz J. E. Serrão 《Phytoparasitica》2009,37(3):225-230
Frankliniella schultzei Trybon (Thysanoptera: Thripidae) is an important pest of tomato plants. The need for more healthful foods is stimulating
the development of techniques to increase plant resistance to phytophagous insects. The objective of this research was to
evaluate the effect of calcium silicate and an organic mineral fertilizer, alone or in combination, on the resistance of tomato
plants to F. schultzei. The treatments consisted of: control (T1), calcium silicate (T2), organic mineral fertilizer (T3), and calcium silicate
with organic mineral fertilizer (T4). The mortality of nymphs of this thrips and the number of lesions on tomato leaves were
evaluated after three, six, nine and 12 applications of these products. The number of F. schultzei individuals and of lesions on tomato leaves was lower in treatments T2 and T4 than in T1 and T3, showing a possible increase
in tomato resistance to this pest. The increase in the number of applications of calcium silicate and the organic mineral
fertilizer increased the mortality of nymphs and reduced the damage by this insect on tomato leaves, mainly after nine applications. 相似文献
6.
Incorporation into soil of dry mycelium ofPenicillium chrysogenum, a waste product of the pharmacological industry, enhanced plant growth and reduced root galling caused by the root-knot
nematodeMeloidogyne javanica in cucumber and tomato plants. Incorporation into sandy loam soil in pots of dry mycelium at a concentration of 0.25% (w/w)
resulted in complete protection of cucumber plants from the nematode. The number of juveniles recovered from soils containing
dry mycelium was greatly reduced even at a concentration of 0.1% (w/w). In microplot studies conducted at two sites in two
seasons, with three or four doses, dry mycelium caused a dose-dependent reduction in root galling index (GI) and promotion
of plant growth of cucumber and tomato plants. Inin vitro studies, the water extract of dry mycelium immobilized nematode juveniles and reduced the egg hatching rate, but these effects
were partly reversible after a rinse in water. Soil-drenching of cucumber and tomato seedlings with water extract of dry mycelium
did not reduce GI or number of root-invading juveniles. The results show that dry mycelium promotes plant growth and protects
plants against nematode infection. Protection, however, does not operatevia induced resistance.
http://www.phytoparasitica.org posting April 6, 2003. 相似文献
7.
Dvora Swartzberg Beny Kirshner Dalia Rav-David Yigal Elad David Granot 《European journal of plant pathology / European Foundation for Plant Pathology》2008,120(3):289-297
Botrytis cinerea is a non-specific, necrotrophic pathogen that attacks many plant species, including Arabidopsis and tomato. Since senescing leaves are particularly susceptible to infection by B. cinerea, we hypothesized that the fungus might induce senescence as part of its mode of action and that delaying leaf senescence
might reduce the severity of B. cinerea infections. To examine these hypotheses, we followed the expression of Arabidopsis SAG12, a senescence-specific gene, upon infection with B. cinerea. Expression of SAG12 is induced by B. cinerea infection, indicating that B. cinerea induces senescence. The promoter of SAG12, as well as that of a second Arabidopsis senescence-associated gene, SAG13, whose expression is not specific to senescence, were previously analyzed in tomato plants and were found to be expressed
in a similar manner in the two species. These promoters were previously used in tomato plants to drive the expression of isopentenyl
transferase (IPT) from Agrobacterium to suppress leaf senescence (Swartzberg et al. in Plant Biology 8:579–586, 2006). In this study, we examined the expression
of these promoters following infection of tomato plants with B. cinerea. Both promoters exhibit high expression levels upon B. cinerea infection of non-senescing leaves of tomato plants, supporting our conclusion that B. cinerea induces senescence as part of its mode of action. In contrast to B. cinerea, Trichoderma harzianum T39, a saprophytic fungus that is used as a biocontrol agent against B. cinerea, induces expression of SAG13 only. Expression of IPT, under the control of the SAG12 and SAG13 promoters in response to infection with B. cinerea resulted in suppression of B. cinerea-induced disease symptoms, substantiating our prediction that delaying leaf senescence might reduce susceptibility to B. cinerea.
Contribution from the Agriculture Research Organization, The Volcani Center, Bet Dagan, Israel, No. 127/2006 series. 相似文献
8.
Masato?Kawabe Kohei?Mizutani Takanobu?Yoshida Tohru?Teraoka Katsuyoshi?Yoneyama Isamu?Yamaguchi Tsutomu?Arie
We selected a reduced-pathogenicity mutant of Fusarium oxysporum f. sp. lycopersici, a tomato wilt pathogen, from the transformants generated by restriction enzyme-mediated integration (REMI) transformation. The gene tagged with the plasmid in the mutant was predicted to encode a protein of 321 amino acids and was designated FPD1. Homology search showed its partial similarity to a chloride conductance regulatory protein of Xenopus, suggesting that FPD1 is a transmembrane protein. Although the function of FPD1 has not been identified, it does participate in the pathogenicity of F. oxysporum f. sp. lycopersici because FPD1-deficient mutants reproduced the reduced pathogenicity on tomato.The nucleotide sequence data reported are available in the DDBJ/EMBL/GenBank databases under the accession number AB110097 相似文献
9.
Yongxiang Zhang Ewen M. Callaway Jeffrey B. Jones Mark Wilson 《European journal of plant pathology / European Foundation for Plant Pathology》2009,124(3):379-390
The plasmid pUFZ75 conferred constitutive GFP expression on the bacterial pathogen Xanthomonas euvesicatoria (syn. X. campestris pv. vesicatoria). Colonisation of the tomato phyllosphere and invasion of tomato leaves by X. euvesicatoria was examined using both fluorescence and confocal laser scanning microscopy. Xanthomonas euvesicatoria established a limited population on the tomato leaf surface, primarily occupying the depressions between epidermal cells
and around the stomata, prior to invasion of the leaf via the stomata and subsequent growth within the substomatal chamber
and the leaf apoplast. Additionally, hrp-gfp fusions were used to report on the temporal and spatial expression of hrp genes during epiphytic colonisation and invasion. Xanthomonas euvesicatoria cells carrying hrpG- and hrpX-gfp reporter constructs were not fluorescent in vitro on non-hrp-inducing LB agar but did exhibit a low level of fluorescence on the leaf surface within 24 h of inoculation, particularly
in the vicinity of stomata. Cells carrying hrpG- and hrpX-gfp fusions exhibited high levels of fluorescence 72 h after inoculation in the substomatal chamber and the leaf apoplast. Cells
carrying the hrpF-gfp fusion were slightly fluorescent on LB agar and showed no further increase in fluorescence on the leaf surface by 24 h after
inoculation, but did show a significant increase in fluorescence 72 h after inoculation in the substomatal chamber and apoplast.
The apparent low-level induction of the regulators hrpG and hrpX on the tomato leaf surface may suggest that some of the genes of the X. euvesicatoria HrpG/HrpX regulon are up- or down-regulated prior to invasion of the stomata while still on the leaf surface. 相似文献
10.
Takeshi?Sameshima Koichi?Kashimoto Keiko?Kida Yoshinori?Matsuda Teruo?Nonomura Koji?Kakutani Kengo?Nakata Shin-ichi?Kusakari Hideyoshi?Toyoda
Leaves of tomato and barley were inoculated with conidia of Blumeria graminis f. sp. hordei race 1 (R1) or Oidium neolycopersici (KTP-01) to observe cytological responses in search of resistance to powdery mildew. Both conidia formed appressoria at similar rates on tomato or barley leaves, indicating that no resistance was expressed during the prepenetration stage of these fungi. On R1-inoculated tomato leaves, appressoria penetrated the papillae, but subsequent haustorium formation was inhibited by hypersensitive necrosis in the invaded epidermal cells. On the other hand, KTP-01 (pathogenic to tomato leaves) successfully developed functional haustoria in epidermal cells to elongate secondary hyphae, although the hyphal elongation from some conidia was later suppressed by delayed hypersensitive necrosis in some haustorium-harboring epidermal cells. Thus, the present study indicated that the resistance of tomato to powdery mildew fungi was associated with a hypersensitive response in invaded epidermal cells but not the prevention of fungal penetration through host papilla. 相似文献
11.
Akira Masunaka Kazuhiro Nakaho Masao Sakai Hideki Takahashi Shigehito Takenaka 《Journal of General Plant Pathology》2009,75(4):281-287
The biocontrol agent Pythium oligandrum (PO) can suppress bacterial wilt caused by Ralstonia solanacearum (RS) in tomato. To understand the primary biocontrol mechanisms of bacterial wilt by PO, we pretreated tomato plants with
sterile distilled water or preinoculated them with PO, followed by inoculation with RS, then observed PO and RS in fixed sections
of tomato tissues using a confocal laser-scanning microscope and fluorescence labeling until 14 days after the inoculation
with RS. Horizontal and vertical movement of RS bacteria was frequently observed in the xylem vessels of roots and stems of
tomato plants (cv. Micro-Tom) that had not been inoculated with PO. In plants that were preinoculated with PO, the movement
of RS was suppressed, and bacteria appeared to be restricted to the pit of vessels, a reaction similar to that observed in
resistant rootstocks. PO colonization was mainly observed at the surfaces of taproots, the junctions between taproots and
lateral roots, and the middle sections of the lateral roots. PO was not observed near wound sites or root tips where RS tended
to colonize. However, RS colonization was significantly repressed at these sites in PO preinoculated plants. These observations
suggest that the induction of plant defense reactions is the main mechanism for the control of tomato bacterial wilt by PO,
not direct competition for infection sites. 相似文献
12.
Domenico Rongai Claudio Cerato Luca Lazzeri 《European journal of plant pathology / European Foundation for Plant Pathology》2009,124(4):613-619
This study examines the effects of a vegetable fungicide on sugar beet powdery mildew (Erysiphe betae) and cucumber powdery mildew (Erysiphe cichoracearum). The formulations consisting of a dispersion of Brassicaceae meal in vegetable or mineral oils on infected leaves of sugar beet, reared in the greenhouse, and of musk melons cultivated
under plastic tunnels, were tested in comparison to each oil taken separately. Both formulations containing Brassicaceae meals, caused 94% of conidia to be distorted while for the untreated group only 2% were distorted. Furthermore, the leaf
area infected by E. betae was 56% for untreated plants and 2.7 and 9.9% respectively, for plants treated with meal containing mineral and vegetable
oil. Vegetable oil considered separately or with Brassicaceae meals showed no phytotoxicity, while the formulations based on mineral oil showed a significantly lower fresh and dry weight
on tomato plants. The low level or absence of phytotoxicity of plants treated with vegetable oil formulations suggests that
to improve the efficacy of powdery mildew control, they could be used mixed with sulphur. The efficiency of the vegetable
formulations in the powdery mildew control observed during these trials encourages further investigation on other parasitic
fungi and foliar pathogens. 相似文献
13.
Among the factors affecting the quality and yield of garlic production, blue mold caused by -- Penicillium spp. -- is responsible for economical losses in many countries. Allicin, present in garlic bulbs, has been suggested as having antifungal activity against some Penicillium species. This study was conducted to evaluate the response of garlic accessions against Penicillium hirsutum infection and to compare this response with bulb allicin content. Twelve garlic accessions were inoculated with P. hirsutum, and assayed in greenhouse and growth chamber experiments. Plant growth parameters and the fungal production of conidia were evaluated. Significant differences were found among the accessions. Accessions Castaño and Morado were most resistant whereas AR-I-125 and Fuego were always severely affected by the disease. A low correlation was found (r = 0.17) between allicin content and tolerance, indicating that allicin is not the main factor involved in the resistance against P. hirsutum. 相似文献
14.
Keisuke Tomioka Yuuri Hirooka Takayuki Aoki Toyozo Sato 《Journal of General Plant Pathology》2008,74(3):264-266
Severe rot of leaves, peduncles and flowers caused by Gibberella zeae (anamorph: Fusarium
graminearum) was found on potted plants of hyacinth (Hyacinthus orientalis), a liliaceous ornamental, in greenhouses in Kagawa Prefecture, Japan, in January 2001. This disease was named “Fusarium
rot of hyacinth” as a new disease because only the anamorph, F.
graminearum, was identified on the diseased host plant.
The authors contributed equally to this work.
The fungal isolate and its nucleotide sequence data obtained in this study were deposited in the Genebank, National Institute
of Agrobiological Sciences and the DDBJ/EMBL/GenBank databases under the accession numbers MAFF239499 and AB366161, respectively. 相似文献
15.
Ricardo B. Baldassari Ester Wickert Antonio de Goes 《European journal of plant pathology / European Foundation for Plant Pathology》2008,120(2):103-110
In the present study, the pathogenicity of 36 isolates of Guignardia species isolated from asymptomatic ‘Tahiti’ acid lime fruit peels and leaves, ‘Pêra-Rio’ sweet orange leaves and fruit peel
lesions, and a banana leaf were characterized. For pathogenicity testing, discs of citrus leaves colonized by Phyllosticta citricarpa under controlled laboratory conditions were kept in contact with the peels of fruit that were in susceptible states. In addition,
pathogenicity was related to morphological characteristics of colonies on oatmeal (OA) and potato dextrose agar (PDA). This
allowed the morphological differentiation between G. citricarpa and G. mangiferae. Polymerase chain reactions (PCRs) were also used to identify non-pathogenic isolates based on primers specific to G. citricarpa. A total of 14 pathogenic isolates were detected during pathogenicity tests. Five of these were obtained from leaf and fruit
tissues of the ‘Tahiti’, which until this time had been considered resistant to the pathogen. Given that the G. citricarpa obtained from this host was pathogenic, it would be more appropriate to use the term insensitive rather than resistant to
categorize G. citricarpa. A non-pathogenic isolate was obtained from lesions characteristic of citrus black spot (CBS), indicating that isolation
of Guignardia spp. under these conditions does not necessarily imply isolation of pathogenic strains. This also applied to Guignardia spp. isolates from asymptomatic citrus tissues. Using fluorescent amplified fragment length polymorphism (fAFLP) markers,
typically pathogenic isolates were shown to be more closely related to one another than to the non-pathogenic forms, indicating
that the non-pathogenic isolates display higher levels of genetic diversity. 相似文献
16.
Soledad Verdejo-Lucas F. Javier Sorribas 《European journal of plant pathology / European Foundation for Plant Pathology》2008,121(1):103-107
Nematode reproduction on the nematode-susceptible tomato cv. Durinta grafted onto the Mi-resistance gene tomato rootstock SC 6301 was compared to the Mi-resistance gene tomato cv. Monika in a plastic house infested with Meloidogyne javanica. The ungrafted susceptible cv. Durinta was included as a control for reference. Final soil population densities were lower
(P ≤ 0.05) on the resistant than susceptible cultivar but intermediate values were recorded on the rootstock SC 6301. The lowest
numbers of eggs per gram root were recorded on the resistant cultivar followed by those on the rootstock; in both cases, they
were lower (P < 0.05) than on the susceptible control. Cumulative yield (kilogram per square meter) was higher (P < 0.05) on the resistant than susceptible cultivar whether or not it had been grafted. The rootstock SC 6301 provided an
intermediate resistance response to M. javanica and was less effective than the resistant cultivar in suppressing nematode populations and plant damage under the experimental
conditions of this study. 相似文献
17.
Susanne Vogelgsang Michael Sulyok Andreas Hecker Eveline Jenny Rudolf Krska Rainer Schuhmacher Hans-Rudolf Forrer 《European journal of plant pathology / European Foundation for Plant Pathology》2008,122(2):265-276
In a field experiment between 2004 and 2006, 14 winter wheat varieties were inoculated with either a mixture of three isolates
of F. poae or a mixture of three isolates of F. avenaceum. In a subsequent climate chamber experiment, the wheat variety Apogee was inoculated with individual single conidium isolates
derived from the original poly conidium isolates used in the field. Disease symptoms on wheat heads were visually assessed,
and the yield as well as the fungal incidence on harvested grains (field only) was determined. Furthermore, grains were analysed
using LC-MS/MS to determine the content of Fusarium mycotoxins. In samples from field and climate chamber experiments, 60 to 4,860 μg kg−1 nivalenol and 2,400 to 17,000 μg kg−1 moniliformin were detected in grains infected with F. poae and F. avenaceum, respectively. Overall, isolate mixtures and individual isolates of F. avenaceum proved to be more pathogenic than those of F. poae, leading to a higher disease level, yield reductions up to 25%, and greater toxin contamination. For F. poae, all variables except for yield were strongly influenced by variety (field) and by isolate (climate chamber). For F. avenaceum, variety had a strong effect on all variables, but isolate effects on visual disease were not reflected in toxin production.
Correlations between visual symptoms, fungal incidence, and toxin accumulation in grains are discussed. 相似文献
18.
Toyozo Sato Jun Okamoto Yosuke Degawa Shigeru Matsunari Kokichi Takahashi Keisuke Tomioka 《Journal of General Plant Pathology》2009,75(1):46-51
In some areas of Japan, yellow spots with white pustules on leaves, stems, petioles, peduncles and calyces were found on Ipomoea nil, I. triloba, I. lacunosa and I. hederacea var. integriuscula. We demonstrated that the diseases on I. nil, I. triloba and I. lacunosa were caused by host-specific strains of Albugo ipomoeae-panduratae and defined three forma speciales of the fungus, respectively, for the three Ipomoea species: “f. sp. nile”, “f. sp. trilobae” and “f. sp. lacunosae”. Because the diseases were new to Japan, we coined the Japanese name “shirosabi-byo”, which means white rust. We also showed
that the disease on I. hederacea var. integriuscula was caused by A. ipomoeae-hardwickii. We named this new disease “white rust (shirosabi-byo in Japanese)”. 相似文献
19.
A new bacterial black spot disease was observed on Odontoglossum, Odontioda, Odontocidium, and Vuylstekeara orchids in Japan. Typical symptoms on the leaves were dark or black spots (or both) with a yellow halo. The causal agent was identified as Burkholderia andropogonis (Smith 1911) Gillis, Van Van, Bardin, Goor, Hebbar, Willems, Segers, Kersters, Heulin and Fernandez 1995. The isolates were pathogenic on four original host orchids, Phalaenopsis orchid, and tulip; they were not pathogenic on white clover or corn after needle stab inoculation. An antibiotic bactericide (oxytetracycline/streptomycin mixture WP) was most effective for controlling the disease. 相似文献
20.
Severe spotting, blight and drop of leaves caused by Colletotrichum dematium were found on potted plants of Polygonatum falcatum, a liliaceous ornamental, in open fields in Kagawa Prefecture, Japan, in May 2001. This new disease was named anthracnose
of P. falcatum.
Keisuke Tomioka, Jouji Moriwaki, Toyozo Sato contributed equally to this work.
The fungal isolate and its nucleotide sequence data obtained in this study were deposited in Genebank, National Institute
of Agrobiological Sciences and the DDBJ/EMBL/GenBank databases under accessions MAFF239500 and AB334523, respectively. 相似文献