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1.
The vascular wilt pathogen Fusarium oxysporum f. sp. melonis causes worldwide yield losses of muskmelon. In this study, we characterized a UV-induced non-pathogenic mutant (strain 4/4) of F. oxysporum f. sp. melonis, previously identified as a potential biological control agent. During comparative analysis of vegetative growth parameters using different carbon sources, mutant strain 4/4 showed a delay in development and secretion of extracellular enzymes, compared to the wild type strain. Amendments of the growth medium with yeast extract, adenine or hypoxanthine, but not guanine, complemented the growth defect of strain 4/4, as well as secretion and partial activity of cellulases and endopolygalacturonases, indicating that the strain is an adenine auxotroph. Incubation of strain 4/4 conidia in adenine solution, prior to inoculation of muskmelon plants, partially restored pathogenicity to the mutant strain. 相似文献
2.
Twenty-seven seed samples belonging to the lettuce cultivars most frequently grown in Lombardy (northwestern Italy), in an
area severely affected by Fusarium wilt of lettuce, were assayed for the presence ofFusarium oxysporum on a Fusarium-selective medium. Isolations were carried out on subsamples of seeds (500 to 1500) belonging to the same seed
lots used for sowing, and either unwashed or disinfected in 1% sodium hypochloride. The pathogenicity of the isolates ofF. oxysporum obtained was tested in four trials carried out on lettuce cultivars of the butterhead type, very susceptible to Fusarium
wilt. Nine of the 27 samples of seeds obtained from commercial seed lots used for sowing in fields affected by Fusarium wilt
were contaminated byF. oxysporum. Among the 16 isolates ofF. oxysporum obtained, only one was isolated from disinfected seeds. Three of the isolates were pathogenic on the tested cultivars of
lettuce, exhibiting a level of pathogenicity similar to that of the isolates ofF. oxysporum f.sp.lactucae obtained from infected wilted plants in Italy, USA and Taiwan, used as comparison. The results obtained indicate that lettuce
seeds are a potential source of inoculum for Fusarium wilt of lettuce. The possibility of isolatingF. oxysporum f.sp.lactucae, although from a low percent of seeds, supports the hypothesis that the rapid spread of Fusarium wilt of lettuce observed
recently in Italy is due to the use of infected propagation material. Measures for prevention and control of the disease are
discussed.
http://www.phytoparasitica.org posting Dec. 16, 2003. 相似文献
3.
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
4.
Seed treatments with essential oils (from savory and thyme) and biocontrol agents (Pseudomonas spp. and Fusarium oxysporum) have been evaluated in vivo after dry hot air treatments against Fusarium oxysporum f. sp. basilici on basil seeds. The savory and thyme essential oils showed a significant pathogen control activity because of their innate antifungal activity and because of the seed application method, but the dry hot pre-treatment did not show any obvious effect on the performance of the essential oil treatments. The dry heat treatment improved the Pseudomonas seed dressing effect against F.oxysporum f. sp. basilici, and showed important reductions in plant infection and the disease index on the treated seed plants, without any negative effect on seed germination. However, the pathogen control provided by the heat treatments combined with the application of the biocontrol agents never reached the same performance as the chemical treatments considered as the reference. Thus, short dry heat treatments on basil seeds have been shown to be a valid but complementary seed disinfection method against Fusarium wilt. 相似文献
5.
The objective of the current study was to characterize Fusarium oxysporum f. sp. radicis-cucumerinum isolates from cucumbers in Turkey in terms of pathogenicity, vegetative compatibility and amplified fragment length polymorphism
(AFLP) variation. In the 2007 and 2008 greenhouse cucumber-growing seasons, surveys were conducted in Adana, Antalya, Hatay
and Mersin provinces of the Mediterranean region of Turkey. Forty-seven fungal isolates of F. oxysporum were recovered from diseased cucumber plants. The pathogenicity of each isolate was tested on cucumber seedlings at the one-true-leaf
stage. Forty of the 47 isolates of F. oxysporum were virulent on cucumber seedlings. Based on disease symptoms, the differential effect of temperatures of 17°C and 29°C
on disease development, and the virulence on cucumber seedlings, these 40 isolates were identified as F. oxysporum f. sp. radicis-cucumerinum. Nitrate non-utilizing mutants were generated on minimal medium containing 1.5% KClO3 and their phenotypes were determined. Mutants in different phenotypic classes were paired on minimal medium; of 40 F. oxysporum f. sp. radicis-cucumerinum isolates, thirty-eight were placed into VCG 0260. Remaining two strains were assigned to VCG 0261. The AFLP primers produced
a total of 180 fragments between 200 and 500 bp in length for the 30 isolates tested. At a genetic similarity of 0.71, the
UPGMA analysis separated the isolates into two distinct clusters. The first cluster, AFLP I, included 28 isolates, of which
all belonged to VCG 0260. Two strains in the second AFLP cluster both belonged to VCG 0261. 相似文献
6.
Montserrat Ramírez-Suero Anas Khanshour Yves Martinez Martina Rickauer 《European journal of plant pathology / European Foundation for Plant Pathology》2010,126(4):517-530
Fusarium wilt is a soil-borne disease caused by formae specialis of Fusarium oxysporum on a large number of cultivated and wild plants. The susceptibility of the model legume plant Medicago truncatula to Fusarium oxysporum was studied by root-inoculating young plants in a miniaturised hydroponic culture. Among eight tested M. truncatula lines, all were susceptible to F. oxysporum f.sp. medicaginis, the causal agent of Fusarium wilt in alfalfa. However, a tolerant line, F83005.5, and a susceptible line, A17, could be
distinguished by scoring the disease index. The fungus was transformed with the GFP marker gene and colonisation of the plant
roots was analysed by epifluorescence and confocal microscopy. A slightly atypical pattern of root colonisation was observed,
with massive fungal growth in the cortex. Although colonisation was not significantly different between susceptible and tolerant
plants, the expression of some defence-related genes showed discrimination between both lines. A study with 10 strains from
various host-plants indicated that M. truncatula was a permissive host to F. oxysporum. 相似文献
7.
Keigo Inami Chizu Yoshioka Yasushi Hirano Masato Kawabe Seiya Tsushima Tohru Teraoka Tsutomu Arie 《Journal of General Plant Pathology》2010,76(2):116-121
Five primer/probe sets to identify the tomato wilt pathogen, Fusarium oxysporum f. sp. lycopersici (FOL), and its three races selectively were designed based on the rDNA-intergenic spacer and avirulence genes. Real-time PCR using
genomic DNA from mycelia and soil DNA with the primer/probe sets allowed the successful identification of FOL and its races. 相似文献
8.
Waseem Raza Xingming Yang Hongsheng Wu Yang Wang Yangchun Xu Qirong Shen 《European journal of plant pathology / European Foundation for Plant Pathology》2009,125(3):471-483
A bacterial strain was isolated from the rhizosphere of healthy watermelon plants in a heavily wilt-diseased field. This isolate
was tentatively identified as Paenibacillus polymyxa (SQR-21) based on biochemical tests and partial 16S rRNA sequence similarity. The purified antifungal compounds were members
of the fusaricidin group of cyclic depsipeptides having molecular masses of 883, 897, 947, and 961 Da with an unusual 15-guanidino-3-hydroxypentadecanoic
acid moiety, bound to a free amino group. The strain SQR-21 was not able to produce antifungal volatile compounds but was
able to produce cellulase, mannase, pectinase, protease, β-1,3-glucanase and lipase enzymes. However, the strain did not show
any chitinase activity. Biocontrol potential of this strain was evaluated against Fusarium oxysporum cause of Fusarium wilt disease of watermelon in a greenhouse experiment. This strain combined with organic fertiliser decreased
the disease incidence by 70% and increased the dry plant weight by 113% over the control. 相似文献
9.
Floriane L’Haridon Sébastien Aimé Claude Alabouvette Chantal Olivain 《European journal of plant pathology / European Foundation for Plant Pathology》2007,118(3):239-246
The aim of this study was to assess the biocontrol capacity of rev157, a non-pathogenic mutant of a pathogenic strain of Fusarium oxysporum f. sp. melonis (Fom24). Inoculated in association with the virulent parental strain, the mutant rev157 did not protect the host plant (muskmelon)
against infection by Fom24. Applied on flax, a non-host plant, the mutant rev157 was not able to protect it against its specific
pathogen F. oxysporum f. sp. lini. On the contrary the parental strain Fom24 did protect flax as well as a soil-borne biocontrol strain (Fo47). Since the mutant
rev157 was affected neither in its growth in vitro nor in its capacity to penetrate into the roots, it can be speculated that
the mutation has affected traits responsible for interactions within the plant. In F. oxysporum the pair of strains Fom24/rev157 is a good candidate to identify genes involved in the biocontrol capacity of F. oxysporum and to test the hypothesis of a link between capacity to induce the disease and capacity to induce resistance in the plant. 相似文献
10.
Fusarium wilt is an economically important fungal disease of common eggplant (Solanum melongena) cultivated in the eastern Mediterranean region of Turkey. Seventy-four isolates of Fusarium oxysporum isolated from diseased eggplant displaying typical Fusarium wilt symptoms were screened for pathogenicity on the highly susceptible
cv. ‘Pala’. All the isolates tested were pathogenic to eggplant and designated as Fusarium oxysporum f. sp. melongenae (Fomg). Genetic diversity among a core set of 20 Fomg isolates that were selected based upon geographic locations, were characterized by using pathogenicity, vegetative compatibility
grouping (VCG), and random amplified polymorphic DNA (RAPD) analysis. The area under the disease progress curve (AUDPC) was
calculated for each Fomg isolate until 21 days after inoculation (DAI). The most virulent isolate was identified as Fomg10 based on AUDPC, disease severity and vascular discoloration measurements at 21 DAI. At this date, a good correlation was
observed between disease severity and AUDPC values for all isolates (r = 0.73). UPGMA (unweighted pair group method with arithmetic average) cluster analysis of RAPD data using Dice’s coefficient
of similarity differentiated all the Fomg isolates tested, and indicated considerable genetic variation among Fomg isolates, but isolates from the same geographic region were grouped together. There was no direct correlation between clustering
in the RAPD dendrogram and pathogenicity testing of Fomg isolates. Twenty isolates of Fomg were assigned to VCG 0320. 相似文献
11.
Abu Shamim Mohammad Nahiyan Louisa Robinson Boyer Peter Jeffries Yoh-ichi Matsubara 《European journal of plant pathology / European Foundation for Plant Pathology》2011,130(2):197-203
The diversity of Fusarium populations in asparagus (Asparagus officinalis L.) decline fields in Japan was estimated by PCR-SSCP (single-stranded conformational polymorphism) analysis of the ITS2
regions of the nuclear rRNA genes. This method was used to rapidly and objectively identify pathogens associated with roots
of plants showing symptoms of asparagus decline collected from fields in five regions across Japan. Over 651 fusarial isolates
were obtained, and were easily differentiated into three principal species. Fusarium oxysporum f. sp. asparagi was most frequently isolated from the domestic five regions (68%), whereas Fusarium proliferatum (28.6%) was less frequent. Fusarium solani was found much rarely (2.5%). The frequency of isolation of Fusarium proliferatum increased gradually from the north to the south of Japan, though considerable differences were found between fields in each
region, as well as regional differences among the Fusarium populations. Most of the fusarial isolates were highly pathogenic in vitro. These results reveal that Fusarium oxysporum f. sp. asparagi and Fusarium proliferatum are important biotic factors which lead to asparagus decline in Japan. 相似文献
12.
To identify phytoalexins of adzuki bean elicited in response to attempted infection of Phytophthora vignae f. sp. adzukicola, we isolated compounds from adzuki bean and evaluated their antifungal activity. Seven flavonoids (daidzein, genistein, 2′-hydroxygenistein,
coumestrol, dalbergioidin, kievitone, and phaseol) were identified from epicotyls wound-inoculated with a mycelial suspension
of an avirulent race of P. vignae f. sp. adzukicola. Of those compounds, kievitone and dalbergioidin accumulated to higher levels in incompatible interactions compared to compatible
interactions 48 h after inoculation. Kievitone strongly inhibited the germination of encysted zoospores, and dalbergioidin
were slightly suppressive. From these results, we concluded that kievitone and dalbergioidin are phytoalexins in adzuki bean. 相似文献
13.
Ying-Hong Lin Jing-Yi Chang En-Tzu Liu Chih-Ping Chao Jenn-Wen Huang Pi-Fang Linda Chang 《European journal of plant pathology / European Foundation for Plant Pathology》2009,123(3):353-365
Fusarium oxysporum f. sp. cubense is the causal agent of Panama disease of banana. A rapid and reliable diagnosis is the foundation of integrated disease management
practices in commodity crops. For this diagnostic purpose, we have developed a reliable molecular method to detect Foc race
4 isolates in Taiwan. By PCR amplification, the primer set Foc-1/Foc-2 derived from the sequence of a random primer OP-A02
amplified fragment produced a 242 bp size DNA fragment which was specific to Foc race 4. With the optimized PCR parameters,
the molecular method was sensitive and could detect small quantities of Foc DNA as low as 10 pg in 50 to 2,000 ng host genomic
DNA with high efficiency. We also demonstrated that by using our PCR assay with Foc-1/Foc-2 primer set, Foc race 4 could be
easily distinguished from other Foc races 1 and 2, and separated other formae speciales of F. oxysporum.
Electronic supplementary material The online version of this article (doi:) contains supplementary material, which is available to authorized users. 相似文献
14.
Teruo Nonomura Hiromi Tajima Yuko Kitagawa Naoko Sekiya Kayoko Shitomi Mami Tanaka Kazuhiko Maeda Yoshinori Matsuda Hideyoshi Toyoda 《Journal of General Plant Pathology》2003,69(1):45-48
Green fluorescent protein (GFP)-marked Fusarium oxysporum f. sp. melonis and nonmarked F. oxysporum f. sp. fragariae were stained with neutral red. The neutral red stained vacuoles of the fungi without disturbing GFP fluorescence in the cytoplasm.
GFP-marked fungi showed fluorescent hyphae with dark-stained vacuoles, whereas nonmarked fungi were detected as nonfluorescent
hyphae with dark-dotted vacuoles. Root colonization by these two fungi was monitored using this method. Microconidia attached
similarly to the root surface and elongated vegetative hyphae. Only the pathogenic fungi invaded, causing necrosis at the
inoculation site. Thus, the present method enabled us to track simultaneously the various formae speciales of F. oxysporum colonizing the root surface.
Received: March 25, 2002 / Accepted: September 27, 2002 相似文献
15.
Stuti Patel Meenu Saraf 《European journal of plant pathology / European Foundation for Plant Pathology》2017,149(2):425-433
Plant growth promoting Bacillus subtilis MSS9 and Bacillus licheniformis MSS14 were isolated from the tomato rhizosphere. These isolates were capable of inhibiting the fungal pathogen, Fusarium oxysporum f. sp. lycopersici causing fusarium wilt in tomato, tested by dual culture method and by mycolytic enzyme production. The isolates have the capacity to form biofilm on the microtitre plate. Scanning electron microscopy revealed good colonization capacity of Bacillus licheniformis MSS14 on tomato plant root as compared to Bacillus subtilis MSS9, pot experiments were also analyzed to study the effects of both rhizobacterial cultures on pathogen development and plant growth. It was observed that MSS14 reduces the incidence of Fusarium oxysporum f. sp. lycopersici in tomato and there was significant increase in vegetative parameters like root length, shoot length, plant wet weight, dry weight and chlorophyll content after which indicates that the root colonization property of the culture MSS14 helps in enhancing the biocontrol capacity against pathogen than that of MSS9. 相似文献
16.
Two diseases of adzuki bean, brown stem rot (BSR, caused by Cadophora gregata f. sp. adzukicola) and adzuki bean Fusarium wilt (AFW, caused by Fusarium oxysporum f. sp. adzukicola), are serious problems in Hokkaido and have been controlled using cultivars with multiple resistance. However, because a
new race of BSR, designated race 3, was identified, sources of parental adzuki bean for resistance to race 3 were needed.
Therefore, we examined 67 cultivars and lines of cultivated and wild adzuki bean maintained at the Tokachi Agricultural Experiment
Station using a root-dip inoculation method. Consequently, nine adzuki bean cultivars, one wild adzuki bean accession and
30 lines (including two lines resistant to all the three races of BSR and AFW) were confirmed to be resistant or tolerant
to race 3 of BSR, and we found a cultivar Akamame as well as a wild adzuki bean Acc2515 to be a new source for a resistance
gene to the race 3. This cultivar also holds promise as a source of resistance against other races of BSR and AFW. 相似文献
17.
Bacillus amyloliquefaciens IUMC7 isolated from mushroom compost inhibited growth of Fusarium oxysporum f. sp. lycopersici (FOL) on culture plates, and a culture supernatant of IUMC7 inhibited in vitro germ tube elongation of FOL. When compared with control soils, mushroom compost inoculated with IUMC7 significantly reduced disease severity caused by FOL in tomato plants. PCR tests for expression of PR genes indicated that IUMC7 did not induce resistance in tomato plants. These results suggested that the suppression of disease was mainly caused by antimicrobial compounds produced by IUMC7. 相似文献
18.
Ju Ding Kai Shi Yan Hong Zhou Jing Quan Yu 《European journal of plant pathology / European Foundation for Plant Pathology》2009,124(1):141-150
Fusarium wilt, caused by Fusarium oxysporum f. sp. cucumerinum (FO), is one of the major diseases in cucumber (Cucumis sativus) production. Root and foliar applications of 24-epibrassinolide (EBL), an immobile phytohormone with antistress activity,
were evaluated for their effects on the incidence of Fusarium wilt and changes in the microbial population and community in
roots of cucumber plants. EBL pre-treatment to either roots or shoots significantly reduced disease severity followed by an
improved plant growth regardless of the treatment methods applied. EBL applications decreased the Fusarium population on root surfaces and in nutrient solution, but increased the population of fungi and actinobacteria on root surfaces. PCR-DGGE analysis showed that FO-inoculation had significant effects on the bacterial community on root
surfaces as expressed by a decreased diversity index and evenness index, but EBL applications alleviated these changes. Moreover,
several kinds of decomposing bacteria and growth-promoting bacteria were identified from root surfaces of FO-inoculated plants
and EBL-pre-treated plants, respectively. Overall, these results show that the microbial community on root surfaces was affected
by a complex interaction between phytohormone-induced resistance and plant pathogens. 相似文献
19.
Chunyu Li Shi Chen Cunwu Zuo Qingming Sun Qian Ye Ganjun Yi Bingzhi Huang 《European journal of plant pathology / European Foundation for Plant Pathology》2011,131(2):327-340
Fusarium oxysporum f. sp. cubense (Foc) is the causal pathogen of Fusarium wilt of banana. To understand infection of banana roots by Foc race 4, we developed a green fluorescent protein (GFP)-tagged transformant and studied pathogenesis using fluorescence microscopy
and confocal laser scanning microscopy. The transformation was efficient, and GFP expression was stable for at least six subcultures
with fluorescence clearly visible in both hyphae and spores. The transformed Foc isolate also retained its pathogenicity and growth pattern, which was similar to that of the wild type. The study showed
that: (i) Foc race 4 was capable of invading the epidermal cells of banana roots directly; (ii) potential invasion sites include epidermal
cells of root caps and elongation zone, and natural wounds in the lateral root base; (iii) in banana roots, fungal hyphae
were able to penetrate cell walls directly to grow inside and outside cells; and (iv) fungal spores were produced in the root
system and rhizome. To better understand the interaction between Foc race 4 and bananas, nine banana cultivars were inoculated with the GFP-transformed pathogen. Root exudates from these cultivars
were collected and their effect on conidia of the GFP-tagged Foc race 4 was determined. Our results showed that roots of the Foc race 4-susceptible banana plants were well colonized with the pathogen, but not those of the Foc race 4-resistant cultivars. Root exudates from highly resistant cultivars inhibited the germination and growth of the Fusarium
wilt pathogen; those of moderately resistant cultivars reduced spore germination and hyphal growth, whereas the susceptible
cultivars did not affect fungal germination and growth. The results of this work demonstrated that GFP-tagged Foc race 4 isolates are an effective tool to study plant–fungus interactions that could potentially be used for evaluating resistance
in banana to Foc race 4 by means of root colonization studies. Banana root exudates could potentially also be used to identify cultivars in
the Chinese Banana Germplasm Collection with resistance to the Fusarium wilt pathogen. 相似文献
20.
Hina Ali Muhammad Ahsan ul Haq Tariq Mahmud Shah Mehboob ur Rahman Weidong Chen 《European journal of plant pathology / European Foundation for Plant Pathology》2012,132(2):237-244
DNA markers in chickpea, targetting resistance genes for different races of Fusarium oxysporum f.sp. ciceris (Foc), have been identified in chickpea, but validation of these markers is essential for effective use in resistance breeding.
In view of this, different simple sequence repeats (SSR) markers were analysed in Pakistani germplasm including induced mutants
and some local lines. Most of the SSR markers showed good correlation with phenotypic evaluation of genotypes to different
races of Foc and may be used effectively in resistance breeding, except those markers for race 3. Markers for race 3 showed
deviations from phenotypic data and the reason might be that race 3 is actually Fusarium proliferatum as reported recently and resistance to this race might involve some other major resistance genes. Poor correlation of markers
with foc-3 on LG2 in our study and a recent report of independent segregation of foc-2 and foc-3 in near isogenic lines suggested that linkage distances among different resistance genes need further investigation. Moreover
three Pakistani mutant lines (97477, CM444/92 and CM368/93) depicted high levels of resistance to Foc races and can be deployed
as a valuable source in resistance breeding programmes. 相似文献