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1.
Guillermo A. Galván Carole F. S. Koning-Boucoiran Wim J. M. Koopman Karin Burger-Meijer Pablo H. González Cees Waalwijk Chris Kik Olga E. Scholten 《European journal of plant pathology / European Foundation for Plant Pathology》2008,121(4):499-512
The aim of this research was to study levels of resistance to Fusarium basal rot in onion cultivars and related Allium species, by using genetically different Fusarium isolates. In order to select genetically different isolates for disease testing, a collection of 61 Fusarium isolates, 43 of them from onion (Allium cepa), was analysed using amplified fragment length polymorphism (AFLP) markers. Onion isolates were collected in The Netherlands
(15 isolates) and Uruguay (9 isolates), and received from other countries and fungal collections (19 isolates). From these
isolates, 29 were identified as F. oxysporum, 10 as F. proliferatum, whereas the remaining four isolates belonged to F. avenaceum and F. culmorum. The taxonomic status of the species was confirmed by morphological examination, by DNA sequencing of the elongation factor
1-α gene, and by the use of species-specific primers for Fusarium oxysporum, F. proliferatum, and F. culmorum. Within F. oxysporum, isolates clustered in two clades suggesting different origins of F. oxysporum forms pathogenic to onion. These clades were present in each sampled region. Onion and six related Allium species were screened for resistance to Fusarium basal rot using one F. oxysporum isolate from each clade, and one F. proliferatum isolate. High levels of resistance to each isolate were found in Allium fistulosum and A. schoenoprasum accessions, whereas A. pskemense, A. roylei and A. galanthum showed intermediate levels of resistance. Among five A. cepa cultivars, ‘Rossa Savonese’ was also intermediately resistant. Regarding the current feasibility for introgression, A. fistulosum, A. roylei and A. galanthum were identified as potential sources for the transfer of resistance to Fusarium into onion. 相似文献
2.
The clustered hrp genes encoding the type III secretion system in the Japanese strains MAFF301237 and MAFF311018 of Xanthomonas oryzae pv. oryzae were sequenced and compared. The strains differ in their pathogenicity, location, and year of isolation. A 30-kbp sequence comprising 29 open reading frames (ORFs) was identical in its structural arrangement in both strains but differed from X. campestris pv. campestris, X. axonopodis pv. citri, and X. axonopodis pv. glycines in certain genes located between the hpaB-hrpF interspace region. The DNA sequence and the putative amino acid sequence in each ORF was also identical in both X. oryzae pv. oryzae strains as were the PIP boxes and the relative sequences. These facts clearly showed that the structure of the hrp gene cluster in X. oryzae pv. oryzae is unique. 相似文献
3.
Essential oils extracted fromEucalyptus blakelyi (1,8-cineole, 77.5%),Melaleuca fulgens (1,8-cineole, 56.9%) and 1,8-cineole were shown to have fumigant toxicity against different development stages ofSitophilus oryzae. The eggs ofS. oryzae were the most tolerant, followed by pupae, larvae and adults in that order.M. fulgens oil,E. blakelyi oil and 1,8-cineole at 100 μl per liter of air gave, respectively, LT50 values of 16.2, 17.4 and 9.1 h for adults, 31.1, 19.3 and 17.5 h for larvae, 55.6, 75.2 and 39.7 h for pupae, and required
>7 days for eggs. Only 1,8-cineole (200 μl
−1 air) gave a significant egg kill by 7 days and the LT95 was 134.5 h. 1,8-Cineole could be a useful new fumigant.
http://www.phytoparasitica.org posting Oct. 3, 2004. 相似文献
4.
Xiu-Fang Hu Fei-Xiang Ying Yu-Bo He Yuan-Yuan Gao Hai-Min Chen Ji-Shuang Chen 《European journal of plant pathology / European Foundation for Plant Pathology》2008,120(3):305-310
Pinellia ternata is a traditional Chinese herb which has been used in China for over 1,000 years. A soft-rot disease characterized by water-soaked
lesions and soft-rot symptoms with a stinking odour was commonly observed in cultivated fields of this plant, and Pectobacterium-like bacteria were consistently isolated from the infected tissues. Two typical strains (SXR1 and ZJR1), isolated from Shanxi
and Zhejiang, respectively, were identified. Pathogenicity tests revealed that these strains were virulent to P. ternata and induced the same symptoms as observed in the field. Characterization involving fatty acid profile, metabolic and physiological
properties, 16S rDNA sequence and PCR-RFLP identified both isolates as P. carotovorum subsp. carotovorum (Pcc). The 16S rDNA of both isolates shared 97–99% sequence similarity with that of Pcc strains. The phylogenetic trees showed
that both isolates were clustered in the group of Pcc and P. carotovorum subsp. odorifera and both PCR-RFLP profiles were consistent with the pattern E produced by the minority of Pcc strains. Thus, isolates SXR1
and ZJR1 were characterized as Pcc in spite of some differences. This is the first report that Pcc has been proven as a causal
agent of soft-rot disease on P. ternata. 相似文献
5.
A botanical natural product,AkseBio2, was evaluated under laboratory conditions for its oviposition deterrent, ovicidal and larvicidal (nymphicidal) effects against
the pear psyllaCacopsylla pyri (L.) (Hemiptera: Psyllidae). The product exhibited a strong oviposition deterrent effect for winterform and summerform females
and caused a reduction in the total number of eggs laid in both choice and no-choice assays. Significant mortalities in freshly
laid eggs (0–48 h) and various nymphal stages of the pest were recorded in toxicity assays. At a concentration of 0.1% (formulation),
the highest biological activity of the product was recorded against the young (1st and 2nd) nymphal stages (up to 87.4% mortality)
in comparison with the other biological stages of the pest. It was less active against the older (3rd-5th) nymphs, causing
62.1% mortality at the same concentration. In assays with non-target organisms, a significant negative effect was not observed.
There were no significant changes on treated plants up to 7 days after treatment in any trial, nor was there any phytotoxicity
on plant tissue as a result ofAkseBio2 treatments. The results suggest that the product can be used in psylla control instead of synthetic insecticides and may
serve as an integrated pest management (IPM) component in pear orchards.
http://www.phytoparasitica.org posting July 14, 2004. 相似文献
6.
The plasmid-encoded virulence gene psvA was previously isolated from Pseudomonas syringae pv. eriobotryae and sequenced. The deduced protein of the psvA gene had no significant similarity to any other protein sequences in the database. To gain a better understanding of the function of the PsvA protein its subcellular localization was examined. To localize the PsvA protein within the bacteria, the cells were fractionated into cytoplasmic, inner membrane, and outer membrane components. The cell fractions and culture supernatant were analyzed by immunoblotting. The PsvA protein was predominantly detected in the outer membrane fraction. Immunoelectron microscopy also showed that the PsvA protein was located in the outer membrane. 相似文献
7.
The biotype status of samples of the whiteflyBemisia tabaci (Gennadius) (Hemiptera: Aleyrodidae) collected from several field and greenhouse sites in Israel during 1999–2000 was determined
by polyacrylamide gel electrophoresis (PAGE) for general esterases, and by RAPD-PCR using primers of arbitrary sequence. Results
of this survey provide the first published evidence for the occurrence of theB. tabaci Q biotype, alongside the more widely distributed B biotype. Based on the collected samples, it appears that both the B and
Q biotypes are present in Israel, and that field populations consist of a mixture of the two biotypes. A possible link betweenB. tabaci biotypes and insecticide resistance is discussed.
Contribution no. 508/02 from the Inst. of Plant Protection, ARO, The Volcani Center, Bet Dagan, Israel.
http://www.phytoparasitica.org posting Dec. 5, 2002. 相似文献
8.
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
9.
Shigemitsu Kimura Susumu Tokumaru Kazuhiko Kuge 《Journal of General Plant Pathology》2009,75(4):322-324
Yeast-like fungi were isolated from lesions on azuki bean (cv. Shin-Kyotodainagon) seeds that had been sucked by bean bugs
in Kyoto Prefecture, Japan. On the basis of morphological and physiological characteristics and sequence data of the internal
transcribed spacer (ITS) regions including the 5.8S rDNA, these yeasts were identified as Eremothecium coryli and E. ashbyi. Pathogenicity of those yeasts was confirmed by a reinoculation test. To our knowledge, this is the first report of the occurrence
of yeast spot in azuki bean in Japan.
The nucleotide sequence data reported are available in the GeneBank/EMBL/DDBJ database as accessions AB478291–AB478309 for
E. coryli AZC1–19 and AB478310–AB478317 for E. ashbyi AZA1–8. 相似文献
10.
Mikiko Harada Satoshi Ishikawa Tadaaki Hibi Kyoko Watanabe 《Journal of General Plant Pathology》2008,74(4):341-343
In 2003–2004, anthracnoses of Enkianthus campanulatus and Rhynchosia acuminatifolia were found for the first time in Kanagawa Prefecture and Tokyo in Japan. These pathogens were identified as Colletotrichum gloeosporioides based on their pathogenicity, morphology and ribosomal DNA spacer sequences.
Results were presented at the annual meeting of The Phytopathological Society of Japan in 2004. 相似文献
11.
The study deals with the tachinid parasitoids ofAncyrosoma leucogrammes (Gmelin) (Heteroptera: Pentatomidae):Clytiomya dupuisi Kugler,Clytiomya sola (Rondani) andGymnosoma clavatum (Rohdendorf) (Diptera: Tachinidae). All species are recorded for the first time as parasitoids ofA. leucogrammes, andC. dupuisi was reared for the first time from a host. The parasitization rates ofC. dupuisi on adults ofA. leucogrammes varied from 7% to 9% between 1994 and 1999.C. sola andG. clavatum were reared in only small numbers.
http://www.phytoparasitica.org posting July 10, 2003. 相似文献
12.
The present study was conducted to determine if there is specificity in the host-pathogen relationship between the isolates
of Xanthomonas oryzae pv. oryzae, the causal bacterium for rice blight and Leersia grasses, the alternative weed hosts of the disease. Plants of three species of Leersia, namely, L. sayanuka, L. oryzoides and L. japonica, were collected from various parts of Japan and were inoculated with the X. oryzae pv. oryzae isolates obtained from various locations in Japan and from 11 Asian countries. Four L. sayanuka plants were found susceptible to all Race II isolates and some Race I isolates, but were resistant to all Race III isolates.
Race III is known to have a wider range pathogenicity to rice cultivar groups compared with Race I and II. Although the reactions
of two L. oryzoides plants to Race I and II isolates were similar to that of L. sayanuka, the L. oryzoides plant collected from Niigata Prefecture showed a susceptible reaction to some Race III isolates. On the other hand, L. japonica plants gave reactions different those of L. sayanuka and L. oryzoides, with two plants of L. japonica found to be resistant to all test isolates collected from Japan. The Asian isolates exhibited a wide host range against the
international differential rice cultivars, but almost all of them were avirulent to Leersia plants. These results indicate that the relationship between the pathogenicity of the causal bacterium and the resistance
of host plants is very complex, and suggest that pathogenic diversity of X. oryzae pv. oryzae might be related to the resistance of Leersia spp. 相似文献
13.
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
14.
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
15.
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
16.
Bacterial black spot disease of mango is caused by Xanthomonas campestris pv. mangiferaeindicae (Xcm), which consists of two genotypically and phenotypically distinct groups of strains. Monoclonal antibodies (MABs) were produced – 15 against CFBP 1717, a group I strain, and 9 against CFBP 2919 (yellow-pigmented), a group II strain – and were analyzed for their characteristics. On the avidin-biotin peroxidase complex enzyme-linked immunosorbent assay, the dilution limit of the MABs was between 100 and 200000 and was 10 times higher when measured on the corresponding ascitic fluid. All kinds of isotypes were represented among the MABs. All the Japanese Xcm strains, designated group I by hrp-restriction fragment length polymorphism (RFLP) analysis, reacted equally with MAB 1A7H12G3, which is the most specific for all but one worldwide group I strains, and to only one strain among group II. Also, to various extents, serological heterogeneity inside the two groups was consistently differentiated based on isozyme and RFLP analyses. MAB 1E2E1 against CFBP2919, because of its narrow specificity, and MAB 1A7H12G3 against CFBP1717, because of its broad specificity, will be useful for epidemiological studies or general control of the pathogen. 相似文献
17.
18.
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
19.
Eighteen toxins produced byFusarium species were tested at different concentrations onOrobanche ramosa seeds to evaluate their effectiveness in inhibiting germination. Many of the toxins were active at the highest concentration
used. Seven of them,viz. fusarenon X, nivalenol, deoxynivalenol, T-2 toxin, HT-2 toxin, diacetoxyscirpenol and neosolaniol, were highly active at
10μM, causing 100% inhibition of germination. Many of them were still active when assayed at a concentration ten times lower,
with T-2, HT-2, nivalenol, neosolaniol and diacetoxyscirpenol still able to cause total inhibition; the last mentioned was
very active also at 0.1μM, causing more than 90% inhibition. The results show that the use of toxic secondary metabolites could represent a useful
alternative strategy in the management of parasitic weeds, by interfering with the induced germination process, and that fungal
culture extracts could be an interesting source of new compounds acting as natural and original herbicides.
http://www.phytoparasitica.org posting Sept. 18, 2002. 相似文献