共查询到20条相似文献,搜索用时 31 毫秒
1.
Nevein A. S. Messiha Anne D. van Diepeningen Marcel Wenneker Alexander R. van Beuningen Jaap D. Janse Trudie G. C. Coenen Aad J. Termorshuizen Ariena H. C. van Bruggen Wim J. Blok 《European journal of plant pathology / European Foundation for Plant Pathology》2007,117(4):403-415
The potential of Biological Soil Disinfestation (BSD) to control potato brown rot, caused by Ralstonia solanacearum race 3 biovar 2, was investigated. BSD involves the induction of anaerobic soil conditions by increasing microbial respiration
through incorporation of fresh organic amendments (here: grass or potato haulms) and by reducing re-supply of oxygen by covering
with airtight plastic sheets. Control treatments were left without cover and amendment, or amended without covering or covered
only without amendment. The effect of BSD on survival of R. solanacearum was tested at three different scales: in 1-l glass mesocosms under laboratory conditions, in 1.2-m-diam microplots positioned
in an outdoor quarantine field, and in a naturally infested commercial field. Within a few days, anaerobic conditions developed
in the BSD-treated soils. In the mesocosm and microplot experiment, anaerobic conditions persisted till the end of the 4-week
experimental period. In the field experiment, the period of anaerobiosis was shorter due to birds damaging the plastic cover.
In all three experiments, BSD reduced soil populations of R. solanacearum significantly by 92.5% to >99.9% compared to the non-amended and uncovered control treatments. In the field experiment, BSD
also resulted in a significant reduction of R. solanacearum survival in potato tubers buried at 15 or 35 cm and in the rapid decomposition of superficially buried potatoes remaining
after harvesting, thus destroying an important inoculum reservoir of R. solanacearum. The treatments with grass amendment only or covering with only plastic did not result in anaerobic conditions and did not
decrease R. solanacearum populations during the experimental period. PCR-DGGE analyses of 16S-rDNA from soil samples of the various treatments in
the mesocosm and microplot experiments revealed that BSD hardly affected bacterial diversity but did result in clear shifts
in the composition of the bacterial community. The possible implications of these shifts are discussed. It is concluded that
BSD has the potential to strongly decrease soil infestation levels of R. solanacearum and to become an important element in a sustainable and effective management strategy for potato brown rot, especially in
areas where the disease is endemic. 相似文献
2.
Nevain A. S. Messiha Ariena H. C. van Bruggen Anne D. van Diepeningen Oscar J. de Vos Aad J. Termorshuizen N. N. A. Tjou-Tam-Sin J. D. Janse 《European journal of plant pathology / European Foundation for Plant Pathology》2007,119(4):367-381
Ralstonia solanacearum race 3 biovar 2, the causative agent of potato brown rot (bacterial wilt), is an economically important disease in tropical,
subtropical and temperate regions of the world. In view of previous reports on suppression of the disease by organic amendments,
and the expansion of organic agriculture, it was timely to compare the effects of organic and conventional management and
various amendments on brown rot development in different soils (type: sand or clay; origin: Egypt or the Netherlands). Brown
rot infection was only slightly reduced in organically compared to conventionally managed sandy soils from Egypt, but organic
management significantly increased disease incidence and pathogen survival in Dutch sandy and clay soils, which correlated
with high DOC contents in the organic Dutch soils. There was no correlation between disease incidence or severity and bacterial
diversity in the potato rhizosphere in differently managed soils (as determined by 16S DGGE). NPK fertilization reduced bacterial
wilt in conventional Egyptian soils but not in Dutch soils. Cow manure amendment significantly reduced disease incidence in
organic Dutch sandy soils, but did not affect the bacterial population. However, cow manure did reduce densities of R. solanacearum in Egyptian sandy soils, most probably by microbial competition as a clear shift in populations was detected with DGGE in
these and Dutch sandy soils after manure amendment. Amendment with compost did not have a suppressive effect in any soil type.
The absence of a disease suppressive effect of mineral and organic fertilization in Dutch clay soils may be related to the
already high availability of inorganic and organic nutrients in these soils. This study shows that the mechanism of disease
suppression of soil-borne plant pathogens may vary strongly according to the soil type, especially if quite different types
of soil are used. 相似文献
3.
Taro Mori Katsumi Ozaki Hiromi Matsusaki Naotaka Matsuzoe 《Journal of General Plant Pathology》2007,73(2):142-146
To study the behavior and mutation of Ralstonia solanacearum in Solanum toxicarium, which is resistant to bacterial wilt, S. toxicarium was grown in aseptic culture and inoculated with R. solanacearum. Although 60%–80% of the inoculated plants were wilting after 2 to 3 days, most wilted plants had recovered by 20 days after
inoculation. The pathogen was reisolated from over 98% of inoculated plant stems, but the percentage of recovery decreased
the closer the isolation sites were toward the upper stem sections. Three colony types, characterized as fluidal white, nonfluidal
red, and a mixture of fluidal white and nonfluidal red, were reisolated from the stems. Nonfluidal red colonies were less
virulent on tomato plants than fluidal white colonies. 相似文献
4.
Phialophora gregata f. sp. adzukicola, a causal agent of brown stem rot in adzuki beans, produces phytotoxic compounds: gregatins A, B, C, D, and E. Gregatins
A, C, and D cause wilting and vascular browning in adzuki beans, which resemble the disease symptoms. Thus, gregatins are
considered to be involved in pathogenicity. However, molecular analyses have not been conducted, and little is known about
other pathogenic factors. We sought to isolate nonpathogenic and gregatin-deficient mutants through Agrobacterium tumefaciens-mediated transformation (ATMT) for cloning of pathogenicity-related genes. The co-cultivation of P. gregata and A. tumefaciens for 48 h at 20°C with 200 μM acetosyringone resulted in approximately 80 transformants per 106 conidia. The presence of acetosyringone in the A. tumefaciens pre-cultivation period led to an increase in T-DNA copy number per genome. Of 420 and 110 transformants tested for their
pathogenicity and productivity of gregatins, one nonpathogenic and three gregatin-deficient mutants were obtained, respectively.
The nonpathogenic mutant produced gregatins, whereas the gregatin-deficient mutants had pathogenicity comparable to the wild-type
strain. This is the first report of ATMT of P. gregata. Further analysis of these mutants will help reveal the nature of the pathogenicity of this fungus including the role of
gregatin in pathogenesis. 相似文献
5.
In summer 2010, stems and corms of Amorphophallus konjac with soft rot were collected in Hubei Province, China. Plants were inoculated with the isolated bacterium and developed the
same symptoms, and the reisolated pathogen was identified as Enterobacter sp., based on morphology, pathogenicity and 16S rDNA sequence analysis. 相似文献
6.
Kasumi Takeuchi Keisuke Tomioka Hiroshi Kouchi Tomomi Nakagawa Hisatoshi Kaku 《Journal of General Plant Pathology》2007,73(5):336-341
A wilt disease of the model legume Lotus japonicus was observed in a greenhouse in Tokyo, Japan in May 2004. Roots of diseased plants were rotted and dark brown with lesions
spreading to lower stems and leaves, resulting in rapid plant death. The causal agent was identified as Fusarium solani based on the morphology. Sequence analysis of rDNA supported the identification. Inoculation of roots of healthy plants with
conidia reproduced characteristic disease symptoms, and F. solani was reisolated from lesions, satisfying Koch’s postulates. The isolate also caused chlorotic to necrotic lesions on leaves
of healthy plants after wound-inoculation. Infection by F. solani of leaves of L. japonicus was confirmed histologically. Mycelia were observed in the intercellular spaces of parenchymatous tissues in the lesion area
and the surrounding tissues. This is the first report of fungal disease on L. japonicus satisfying Koch’s postulates. We named it “Fusarium root rot of L. japonicus” as a new disease. The compatibility of L. japonicus and F. solani is expected to form a novel pathosystem for studying interactions between legumes and fungal pathogens.
The nucleotide sequence data reported are available in the DDBJ/EMBL/GenBank databases under accession numbers AB258993 and
AB258994. 相似文献
7.
During the last decade, a new bacterial disease has impaired the yield of vegetable sweet potato (30–80%) in Taiwan. Infected
plants developed stunting, root and stem rot, vascular discoloration and wilting. Ten bacterial isolates that caused the same
symptoms in sweet potatoes after inoculation were reisolated and classified as Ralstonia solanacearum phylotype I biovar 4 based on physical and molecular analyses. Moreover, these isolates also caused wilting in convolvulaceous,
solanaceaous and cruciferous plants. This report is the first of bacterial wilt of sweet potato caused by R. solanacearum in Taiwan. 相似文献
8.
Helena P. Trenado Isabel M. Fortes Diamantina Louro Jesús Navas-Castillo 《European journal of plant pathology / European Foundation for Plant Pathology》2007,118(2):193-196
Tomato chlorosis virus causes yellow leaf disorder epidemics in many countries worldwide. Plants of Physalis ixocarpa showing abnormal interveinal yellowing and plants of Physalis peruviana showing mild yellowing collected in the vicinity of tomato crops in Portugal were found naturally infected with ToCV. Physalis ixocarpa and P. peruviana were tested for susceptibility to ToCV by inoculation with Bemisia tabaci, Q biotype. Results confirmed that ToCV is readily transmissible to both species. The infection was expressed in P. ixocarpa by conspicuous interveinal yellow areas on leaves that developed into red or brown necrotic flecks, while P. peruviana test plants remained asymptomatic. Infected plants of both P. ixocarpa and P. peruviana served as ToCV sources for tomato infection via B. tabaci transmission. This is the first report of P. ixocarpa and P. peruviana as natural hosts of ToCV. 相似文献
9.
Fatma F. Abdel-Motaal Magdi A. El-Sayed Soad A. El-Zayat Mortada S. M. Nassar Shin-ichi Ito 《Journal of General Plant Pathology》2010,76(5):358-361
Floral rot of Egyptian henbane (Hyoscyamus muticus L.) was found on potted plants in a greenhouse in Yamaguchi city, Japan, in the late summer of 2008 and 2009. The symptoms
were identical to those of rots caused by Choanephora species. The pathogen was isolated and identified as C. cucurbitarum (Berkeley and Ravenel) Thaxter. This new disease was named Choanephora rot (Kougai-kabi-byo) of Egyptian henbane. 相似文献
10.
Hideki Watanabe Yoshihiro Taguchi Mitsuro Hyakumachi Koji Kageyama 《Journal of General Plant Pathology》2007,73(2):81-88
Pythium and Phytophthora species were isolated from kalanchoe plants with root and stem rots. Phytophthora isolates were identified as Phytophthora nicotianae on the basis of morphological characteristics and restriction fragment length polymorphism (RFLP) analysis of the rDNA-internal
transcribed spacer regions. Similarly, the Pythium isolates were identified as Pythium myriotylum and Pythium helicoides. In pathogenicity tests, isolates of the three species caused root and stem rots. Disease severity caused by the Pythium spp. and Ph. nicotianae was the greatest at 35°–40°C and 30°–40°C, respectively. Ph. nicotianae induced stem rot at two different relative humidities (60% and >95%) at 30°C. P. myriotylum and P. helicoides caused root and stem rots at high humidity (>95%), but only root rot at low humidity (60%). 相似文献
11.
Fatma F. Abdel-Motaal Magdi A. El-Sayed Soad A. El-Zayat Mortada S. M. Nassar Shin-ichi Ito 《Journal of General Plant Pathology》2009,75(6):437-439
Severe brown spots caused by Cladosporium herbarum appeared on the leaves of Hyoscyamus muticus (Egyptian henbane) grown in a greenhouse at Yamaguchi city, Japan, in the summer of 2008. Nucleotide sequence analysis of
rDNA-ITS and 28S rDNA supported the morphological identification of the isolate, which caused the same disease symptoms after
reinoculation of the host. This new disease was named “Cladosporium leaf spot of Egyptian henbane”. 相似文献
12.
Yukari Uetake Hitoshi Nakamura Ken-ichi Ikeda Masao Arakawa Naoyuki Matsumoto 《Journal of General Plant Pathology》2003,69(1):42-44
Isolates of the violet root rot fungus Helicobasidium mompa were collected from herbaceous and tree plants. Their host preference was studied by inoculation experiments using carrots,
sweet potatoes, and apple stocks. It was found that sweet potato isolates from Kyushu produced infection cushions on carrots
and sweet potatoes but not on apple stocks. Other isolates did not show host preference. Sweet potato isolates were also characterized
by ready hyphal mass (sclerotium) production. They were thought to have adapted to the habitat with high disturbance by annual
tillage.
Received: July 15, 2002 / Accepted: September 26, 2002 相似文献
13.
In June 1995, a disease causing round to irregular-shaped, water-soaked, brown to blackish brown spots on mealycup sage (Salvia farinacea Benth.) was found in Atsugi-shi, Kanagawa Prefecture, Japan. The symptoms were seen only on leaves, not on neither flower
petals or stems. The disease was also found in Setagaya-ku, Tokyo, Memambetsu-cho, Hokkaido and Shimoda-shi and Matsuzaki-cho,
Shizuoka. An Alternaria sp. was frequently isolated from these diseased plants. The isolates were severely pathogenic to mealycup sage and caused
lesions on the inoculated leaves. The isolates were also weakly pathogenic on scarlet sage (S. splendens Sellow ex Roem. and Schult.) but not on any other Labiatae plants tested. Based on morphological characteristics, such as
size of conidia, chain number, and the short beak on conidia, the causal fungus was identified as Alternaria alternata (Fr.) Keissler. This report is the first on a mealycup sage disease caused by A. alternata. Because the symptom was restricted to the leaf, the common name of Alternaria leaf spot was proposed.
Received 30 August 2002/ Accepted in revised form 18 November 2002 相似文献
14.
Rachidatou Sikirou Kerstin Wydra 《European journal of plant pathology / European Foundation for Plant Pathology》2004,110(9):939-947
The survival of Xanthomonas axonopodis pv. vignicola, incitant of cowpea bacterial blight and pustule, in residues of infested cowpea leaves was studied in the field in the forest savanna transition zone of South Benin and under variable controlled conditions. The pathogen survived for up to 60 days when placed on the soil surface, and up to 45 days buried at depths of 10 and 20 cm. In the glasshouse, bacteria survived in residue mixed with soil for at least 2 months in dry soil and less than 2 months in moist soil. The pathogen survived at least 30 days in the field after spray-inoculation on the weed species Euphorbia heterophylla, Digitaria horizontalis and Synedrella nodiflora; 20 days on Panicum subalbidum; 10 days on Euphorbia
hirta; and 5 days on Talinum triangulare. After leaf-infiltration under glasshouse conditions, the pathogen was detected after 90 days in D. horizontalis; 75 days in T.
triangulare, P. subalbidum and S. nodiflora; 60 days in E. hirta, and 30 days in E. heterophylla. Among 12 legume species tested as alternative hosts of X. axonopodis pv. vignicola, only Sphenostylis stenocarpa (African yam bean) showed typical symptoms of cowpea bacterial blight in a glasshouse experiment following artificial inoculation. This is the first time this legume species has been identified as a potential host of X. axonopodis pv.vignicola. Crop residue and weeds are likely sources of primary inoculum when planting two consecutive cowpea crops per year and they probably play a role in dissemination of the pathogen during the cropping season. The alternate host may form a bridge for primary inoculum between cropping seasons. 相似文献
15.
Seisaku Umemoto Katsue Nagashima Shigenobu Yoshida Seiya Tsushima 《Journal of General Plant Pathology》2007,73(4):290-292
In 2002, rotted flower clusters and blighted shoot tips and leaves were observed on highbush blueberry (Vaccinium corymbosum L.) and rabbiteye blueberry (V. ashei Reade) plants in Chiba, Japan. The causal fungus isolated from the diseased plants was morphologically identified as Sclerotinia sclerotiorum (Libert) de Bary. The fungus reproduced natural symptoms after inoculation, then reisolated from the symptomatic parts. This
is the first report of blueberry sclerotinia rot caused by S. sclerotiorum.
The nucleotide sequence data reported are available in the DDBJ/EMBL/GenBank databases under accession numbers AB269903#(020501)
and AB233346 (020505). 相似文献
16.
Anne Moussart Caroline Onfroy Angelique Lesne Magali Esquibet Eric Grenier Bernard Tivoli 《European journal of plant pathology / European Foundation for Plant Pathology》2007,117(1):57-69
Ditylenchus dipsaci, the stem nematode of alfalfa (Medicago sativa), Mycosphaerella pinodes, cause of Ascochyta blight in pea (Pisum sativum) and Aphanomyces euteiches, cause of pea root rot, result in major yield losses in French alfalfa and pea crops. These diseases are difficult to control
and the partial resistances currently available are not effective enough. Medicago truncatula, the barrel medic, is the legume model for genetic studies, which should lead to the identification and characterization
of new resistance genes for pathogens. We evaluated a collection of 34 accessions of M. truncatula and nine accessions from three other species (two from M. italica, six from M. littoralis and one from M. polymorpha) for resistance to these three major diseases. We developed screening tests, including standard host references, for each
pathogen. Most of the accessions tested were resistant to D. dipsaci, with only three accessions classified as susceptible. A very high level of resistance to M. pinodes was observed among the accessions, none of which was susceptible to this pathogen. Conversely, a high level of variation,
from resistant to susceptible accessions, was identified in response to infection by A. euteiches. 相似文献
17.
Judith Hübschen Lilo Kling Ulrike Ipach Volker Zinkernagel Nathalie Bosselut Daniel Esmenjaud Derek J.F. Brown Roy Neilson 《European journal of plant pathology / European Foundation for Plant Pathology》2004,110(8):779-788
Xiphinema diversicaudatum and X. index are vector nematode species of economic importance in viticulture regions as they can transmit Arabis Mosaic, Grapevine Fanleaf and Strawberry Latent Ringspot viruses to grapevine. Wang et al. (2003) designed species-specific diagnostic primers from ribosomal genes for both these vector species as well as a vector and a non-vector species X. italiae and X. vuittenezi, respectively. Our study aimed to confirm the specificity and determine the sensitivity and reliability of the primers for the two vector species, X. diversicaudatumand X. indexwhen challenged with closely related longidorid species and general nematode communities typical of vineyard soil. With one exception, no PCR product was observed when the primers were tested against six Longidorus, one Paralongidorus and one Xiphinema non-target species. Occasionally (three out of eight replicate PCR reactions) a weak PCR product was noted when primers for X. index were tested with L. elongatus. Furthermore, when challenged with a range of non-target nematode species comprising the nematode community typical of viticulture soil, no PCR product was amplified. An experimental dilution series of extracted DNA rigorously demonstrated that DNA from an equivalent single specimen of the target virus-vector species, X. diversicaudatum and/or X. index, could be detected amongst 1000 equivalent non-targetX. vuittenezi. Also, extracted DNA from an equivalent single target specimen was detected when added to DNA extracted from the overall soil nematode community. The primers were assessed further by using serial mixtures of actual nematodes rather than extracted DNA to simulate field soil. Using this method, a single target nematode could be detected amongst 200 non-target specimens. Given their specificity, sensitivity and reliability, it appears that these diagnostic primers will be of great benefit to phytosanitary/quarantine services related to the viticulture industry. 相似文献
18.
19.
Masato Kawabe Kazunori Katsube Takanobu Yoshida Tsutomu Arie Kenichi Tsuchiya 《Journal of General Plant Pathology》2007,73(5):353-359
Twenty-eight isolates of Fusarium oxysporum f. sp. spinaciae (FOS; the causal agent of spinach wilt) collected from Japan were assessed for mating type and subjected to phylogenetic analysis.
Mating type analysis revealed all isolates to be MAT1-2, suggesting that there is no sexual recombination within the population.
Phylogenetic analyses based on nucleotide sequences of the ribosomal DNA intergenic spacer (IGS) and the mating type locus
(MAT1) suggested that FOS is polyphyletic. The cluster analysis based on IGS showed four phylogenetic groups (S1–S4) among the isolates. Two distinct
lineages, S1 and S3, included FOS isolates both of the vegetative compatibility group (VCG) types, 0330 and 0331, demonstrating that VCG differentiation in
FOS may not necessarily reflect the phylogenetic relationships based on IGS and MAT1-2-1. 相似文献
20.
Rui Yang Yong Chao Han Guo Qing Li Dao Hong Jiang Hung Chang Huang 《European journal of plant pathology / European Foundation for Plant Pathology》2007,119(4):411-420
A study was conducted to investigate production of antifungal substances (AFS) by Coniothyrium minitans (Cm), a mycoparasite of Sclerotinia sclerotiorum (Ss), in modified Czapek-Dox (MCD) broth and potato dextrose broth (PDB), and effects of AFS of Cm on mycelial growth and
germination of sclerotia and ascospores of Ss and incidence of leaf blight of oilseed rape caused by Ss. Results showed that
mycelial growth of Ss was reduced by 41.6 and 84.5% on 3 day-old cultures grown on potato dextrose agar (PDA) amended with
10% (v v−1) of cultural filtrates of Cm grown in MCD (MCDcm) after incubation for 6 and 15 days, respectively, and by 2.7 and 15.7% on PDA amended with 10% (v v−1) of cultural filtrates of Cm grown in PDB for 6 and 15 days, respectively. In addition to retardation of mycelial growth,
morphological abnormality of Ss such as hyphal swellings and cytoplasm granulation were also observed in colonies grown on
PDA amended with cultural filtrates of MCDcm. Sclerotia of Ss soaked in the filtrates of MCDcm for 24 h remained viable, but their ability to undergo myceliogenic germination on PDA was delayed, compared to sclerotia
treated with MCD. Germination of ascospores of Ss was unaffected on PDA amended with 10% of the filtrates of MCDcm. However, germ tubes of Ss were shortened and deformed by the formation of hyphal swellings in the treatment of MCDcm. Treatment of leaves of oilseed rape with cultural filtrates of MCDcm reduced incidence of leaf blight caused by Ss, compared to the controls (water or MCD). This study suggests that AFS produced
by Cm plays an important role in the suppression of mycelial growth and germ-tube development of ascospores of Ss and that
there is potential for using AFS of Cm to control leaf blight of oilseed rape caused by ascospores of Ss. 相似文献