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1.
Masamichi Isogai Koji Ishii Seisaku Umemoto Manabu Watanabe Nobuyuki Yoshikawa 《Journal of General Plant Pathology》2009,75(2):140-143
Virus-like symptoms—red ringspots on stems and leaves, circular blotches or pale spots on fruit—were found on commercial highbush
blueberry (Vaccinium
corymbosum) cultivars Blueray, Weymouth, Duke and Sierra in Japan. In PCR testing, single DNA fragments were amplified from total nucleic
acid samples of the diseased blueberry bushes using primers specific to Blueberry red ringspot virus (BRRV). Sequencing analysis of the amplified products revealed 95.7–97.7% nucleotide sequence identity with the BRRV genome.
This paper is the first report of blueberry red ringspot disease caused by BRRV in Japan.
The nucleotide sequence data reported in this paper are available in the GenBank/EMBL/DDBJ database as accessions AB469884
to AB469893 for BRRV isolates from Japan. 相似文献
2.
Alireza Akhavan T. Kelly Turkington Berisso Kebede Kequan Xi Krishan Kumar Andy Tekauz H. Randy Kutcher James R. Tucker Stephen E. Strelkov 《European journal of plant pathology / European Foundation for Plant Pathology》2016,144(2):325-336
Infection by Pyrenophora teres f. teres (Ptt) or P. teres f. maculata (Ptm), the causal agents of the net and spot forms of net blotch of barley, respectively, can result in significant yield losses. The genetic structure of a collection of 128 Ptt and 92 Ptm isolates from the western Canadian provinces of Alberta (55 Ptt, 27 Ptm), Saskatchewan (58 Ptt, 46 Ptm) and Manitoba (15 Ptt, 19 Ptm) were analyzed by simple sequence repeat (SSR) marker analysis. Thirteen SSR loci were examined and found to be polymorphic within both Ptt and Ptm populations. In total, 110 distinct alleles were identified, with 19 of these shared between Ptt and Ptm, 75 specific to Ptt, and 16 specific to Ptm. Genotypic diversity was relatively high, with a clonal fraction of approximately 10 % within Ptt and Ptm populations. Significant genetic differentiation (PhiPT = 0.230, P = 0.001) was found among all populations; 77 % of genetic variation occurred within populations and 23 % between populations. Lower, but still significant genetic differentiation (PhiPT = 0.038, P = 0.001) was detected in Ptt, with 96 % of genetic variation occurring within populations. No significant genetic differentiation (PhiPT = 0.010, P = 0.177) was observed among Ptm populations. Isolates clustered in two distinct groups conforming to Ptt or Ptm, with no intermediate cluster. The high number of haplotypes observed, combined with an equal mating type ratio for both forms of the fungus, suggests that P. teres goes through regular cycles of sexual recombination in western Canada. 相似文献
3.
From the genome of a Japanese field isolate of the rice blast fungus, Magnaporthe oryzae, we newly identified Inago1 and Inago2 LTR retrotransposons. Both elements were found to be Ty3/gypsy-like elements whose copies were dispersed within the genome of Magnaporthe spp. isolates infecting rice and other monocot plants. Southern hybridization patterns of nine re-isolates derived from conidia
of the strain Ina168 produced after a methyl viologen treatment were not changed, indicating that the insertion pattern of
Inago elements is relatively stable. 相似文献
4.
Khalid A. Hussein Mohamed A. A. Abdel-Rahman Ahmed Y. Abdel-Mallek Saad S. El-Maraghy Jin Ho Joo 《Phytoparasitica》2012,40(2):117-126
The greater wax moth Galleria mellonella L. (Lepidoptera: Pyralidae) is occasionally found in beehives and is a major pest of stored wax. Entomopathogenic fungi have
recently received attention as possible biocontrol elements for certain insect pests. In this study, 90 isolates of Beauveria bassiana and 15 isolates of Metarhizium anisopliae were screened for proteases and lipases production. The results showed significant variations in the enzymatic action between
the isolates. In the bioassay, the selected isolates evinced high virulence against the 4th instar of the G. mellonella larvae. The isolates BbaAUMC3076, BbaAUMC3263 and ManAUMC3085 realized 100% mortality at concentrations of 5.5 × 106 conidia ml−1, 5.86 × 105 conidia ml−1, and 4.8 × 106 conidia ml−1, respectively. Strong enzymatic activities in vitro did not necessarily indicate high virulence against the tested insect pest. The cuticle of the infected larvae became dark
and black-spotted, indicating direct attack of fungus on the defense system of the insects. The LC50 values were 1.43 × 103, 1.04 × 105 and 5.06 × 104 for Bba3263AUMC, Bba3076AUMC and Man3085AUMC, respectively, and their slopes were determined by computerized probit analysis
program as 0.738 ± 0.008, 0.635 ± 0.007 and 1.120 ± 0.024, respectively. 相似文献
5.
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
6.
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
7.
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
8.
Akira Kawaguchi 《Journal of General Plant Pathology》2011,77(5):299-303
Forty-one strains of Rhizobium vitis, either tumorigenic (Ti) or nonpathogenic, were characterized using multilocus sequence analysis (MLSA) of the partial nucleotide
sequences of pyrG, recA, and rpoD. The strains separated into seven clades. Rhizobium vitis (Ti) strains isolated from Japan were divided into five genetic groups (A to E), and nonpathogenic R. vitis strains were divided into two genetic groups (F and G). This result suggests that there are new genetic groups of R. vitis in Japan. Among these groups, members of A and B groups are widely distributed throughout Japan. 相似文献
9.
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
10.
Ahmed A. Kheder Yasunori Akagi Hajime Akamatsu Konomi Yanaga Nitaro Maekawa Hiroshi Otani Takashi Tsuge Motoichiro Kodama 《Journal of General Plant Pathology》2012,78(1):30-38
The tomato pathotype of Alternaria alternata (A. arborescens) produces the dark brown to black pigment melanin, which accumulates in the cell walls of hyphae and conidia. Melanin has
been implicated as a pathogenicity factor in some phytopathogenic fungi. Here, two genes of the tomato pathotype for melanin
biosynthesis, ALM1 and BRM2-1, which encode a polyketide synthetase and a 1,3,8-trihydroxynaphthalene (THN) reductase, respectively, have been cloned and
disrupted in the pathogen. The gene-disrupted mutants, alm1 and brm2-1, had albino and brown phenotypes, respectively. The wild-type and the mutants caused the same necrotic lesions on the leaves
after inoculation with spores. These results suggest that melanin is unlikely to play a direct role in pathogenicity in the
tomato pathotype A. alternata. Scanning electron microscopy revealed that the conidia of both mutants have much smoother surfaces in comparison to the
wild-type. The conidia of those mutants were more sensitive to UV light than those of the wild-type, demonstrating that melanin
confers UV tolerance. 相似文献
11.
Davide Giovanardi Davide Dallai Emilio Stefani 《European journal of plant pathology / European Foundation for Plant Pathology》2017,147(4):761-771
Bacterial leaf/fruit spot and canker of stone fruits, caused by Xanthomonas arboricola pv. pruni, is a recurrent disease in Italy. A set of 23 strains has been isolated in peach and plum orchards in an intensively stone fruit cultivated area located in north-eastern Italy. They were all identified as X. arboricola pv. pruni by means of phytopathological and serological features: hypersensitive reaction on bean pods, pathogenicity test on immature peach or plum fruitlets, identification by immunofluorescence assay and conventional PCR. Phylogenetic analysis based on sequencing of the gyrB housekeeping gene of the isolates showed that they formed a unique clade, well characterised and separated from other xanthomonads. An insight into the genetic population features was attempted by rep-PCR analysis, using the ERIC, REP and BOX primers. The combined rep-PCR fingerprints showed a slight intra-pathovar variation within our isolates, which grouped in five close clusters. Copper resistance has been assessed in vitro for our whole X. arboricola pv. pruni collection, highlighting that two isolates show a level of resistance in vitro up to 200 ppm of copper. Nonetheless, the copLAB gene cluster, present in many other species of Xanthomonads, was not detected in any isolate, confirming the presence of a still unknown mechanism of copper detoxification in our Xanthomonads arboricola pv. pruni tolerant/resistant strains. 相似文献
12.
Khalid Pervaiz Akhtar Muhmmad Yussouf Saleem Muhammad Asghar Mushtaq Ahmad Nighat Sarwar 《European journal of plant pathology / European Foundation for Plant Pathology》2010,128(4):435-450
Sixty-nine tomato genotypes representing nine Solanum species were evaluated for resistance to Cucumber mosaic virus (CMV) subgroup IA and its aphid vector Myzus persicae. Resistance was assessed by visual scoring of symptoms in the field under natural conditions, and in the greenhouse by artificial
inoculations through aphid M. persicae and mechanical transmissions in the year 2007 and 2009. Considerable variation in responses was observed among the evaluation
methods used. Field evaluations were found liable to errors as different levels were observed for the same genotypes in the
different years, however mechanical inoculation was found to be the most useful in identifying CMV subgroup IA resistance,
in contrast aphid transmission was most useful in identifying insect transmission resistance. All genotypes observed as highly
resistant to CMV subgroup IA in the field or through vector transmission became systemically infected through mechanical inoculations.
Using mechanical inoculation, six genotypes (TMS-1 of S. lycopersicum, LA1963 and L06049 of S. chilense, LA1353, L06145 and L06223 of S. habrochaites) were found resistant and another six (L06188 and L06238 of S. neorickii, L06219 of S. habrochaites, L05763, L05776 and L06240 of S. pennellii) were found tolerant showing mild symptoms with severity index (SI) ranging 1-2 and with delayed disease development after
a latent period (LP) of 18–30 days. However, these genotypes were found to be resistant to highly resistant in the field and
through inoculation by M. persicae; and they also supported low population levels of M. persicae except TMS-1. Another nine genotypes (LA2184 of S. pimpinellifolium L., LA2727 of S. neorickii, LA0111, L06221, L06127 and L06231 of S. peruvianum L., LA1306, L06057 and L06208 of S. chmielewskii) showing a susceptible response after mechanical inoculation were highly resistant, resistant and tolerant after M. persicae transmission. The resistant genotypes, identified in the present study can be exploited in the breeding programmes aimed
at developing tomato varieties resistant to CMV subgroup IA and broadening the genetic base of CMV-resistant germplasm. The
differences observed between mechanical and aphid transmission suggests that one should consider both evaluation methods for
tomato germplasm screening against CMV subgroup IA. 相似文献
13.
Hu Sun Jing-Ze Zhang 《European journal of plant pathology / European Foundation for Plant Pathology》2009,125(3):459-469
Colletotrichum isolates isolated from cowpea in the Hangzhou area of China were identified as C. destructivum based on morphological characteristics, pathogenicity tests, sequence analysis of the internal transcribed spacer (ITS)1,
5.8S RNA gene and ITS2 regions of ribosomal DNA and the infection process. The ability of the C. destructivum isolates to infect Arabidopsis thaliana was investigated under laboratory conditions and showed a two-phase hemibiotrophic infection process. In addition, the sequences
of the rDNA ITS region of C. destructivum isolates from cowpea were identical with 100% similarity to that of isolates of C. higginsianum originating from cruciferous plants. This article presents new evidence in support of C. higginsianum as a synonym of C. destructivum. 相似文献
14.
Rudra P. Singh Andrea D. Dilworth Xiaoping Ao Mathuresh Singh Virendra K. Baranwal 《European journal of plant pathology / European Foundation for Plant Pathology》2009,124(4):691-694
Surveys of Impatiens and Verbena species in local nurseries in Fredericton, Canada and Verbena species in New Delhi, India showed widespread infection of Citrus exocortis viroid (CEVd) in vegetatively-propagated and seed-grown plants. To determine viroid seed transmission, samples of eight varieties
of Impatiens and 11 varieties of Verbena were obtained from four commercial sources. All 19 samples collected contained viroid infection irrespective of variety.
The presence of viroid in non-germinated seed was 21%, while the transmission rate in seedlings was 66% in Impatiens walleriana in 2006. Following 2 years of seed storage, the respective figures were 6% and 26%. Similarly, in Verbena x hybrida the presence of viroid in seed was 13% in 2006 with a seed-transmission rate in seedlings of 28%, while the respective figures
after 2 years of storage were 5% and 45%. 相似文献
15.
The effects of some fungicides used against citrus diseases, on mycelial growth and conidial germination of Isaria farinosa (Holmsk.) Fries [Sordariomycetes: Hypocreales] and also on the pathogenicity of the fungus on citrus mealybug, Planococcus citri (Risso), were determined. Systemic fungicides such as tebuconazole, penconazole and nuarimol were the most effective as regards
both conidial germination and mycelial growth. Protective fungicides such as captan, chlorothalonil, mancozeb and propineb
inhibited conidial germination at between 1 and 5 μg ml−1 concentration, but captan, chlorothalonil and propineb did not inhibit the mycelial growth at 5,000 μg ml−1. Mancozeb inhibited mycelial growth between 2,500 and 5,000 μg ml−1. Sulphur and copper oxychloride did not inhibit the fungus even at very high concentrations. Sulphur, copper oxychloride,
fosetyl-al, chlorothalonil and carbendazim did not decrease the mortality percentage caused by I. farinosa. Tebuconazole, penconazole and mancozeb were the most effective and respectively reduced the mortality from 83% to 33%, 28%
and 30% in the ovisacs, from 81% to 29%, 27% and 29% in the 1st instar larvae, and from 84% to 34% in the adult females. 相似文献
16.
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
17.
The genomic fragments of two open reading frames (ORFs) 1 and 2 of German and Canadian PAV isolates of Barley yellow dwarf virus (BYDV-PAV) were sequenced. Sequences only slightly differed from previously published sequences of this virus. Two polyclonal antisera against proteins encoded by ORFs 1 and 2 of a German ASL-1 isolate were developed using recombinant antigens expressed in E. coli as a fusion either to His6− or thioredoxin-tags. In Western blot analysis with total protein extracts from BYDV infected plants, antisera efficiently recognized the 99 kDa fusion protein expressed from ORF1 and ORF2 (P1–P2 protein). Later in infection the P1–P2 protein disappeared and two smaller proteins, revealing sizes of 39 and 60 kDa, could be detected. 相似文献
18.
Xiangyang Shi Hong Lin 《European journal of plant pathology / European Foundation for Plant Pathology》2018,150(2):351-362
Type IV pili of X. fastidiosa are regulated by pilG, a response regulator protein putatively involved in chemotaxis-like operon sensing stimuli through signal transduction pathways. To elucidate the roles of pilG in pathogenicity of X. fastidiosa, the pilG-deletion mutant XfΔpilG and complemented strain XfΔpilG-C were generated. While all strains had similar growth curves in vitro, XfΔpliG showed significant reduction in cell-matrix adherence and biofilm production compared with wild-type X. fastidiosa and XfΔpilG-C. The genes pilE, pilU, pilT, and pilS were down-regulated in XfΔpliG when compared with its complemented strain and wild-type X. fastidiosa. Finally, no Pierce’s disease symptoms were observed in grapevines inoculated with XfΔpilG, whereas grapevines inoculated with the wild-type X. fastidiosa and complemented strain of XfΔpilG-C developed typical Pierce’s Disease (PD) symptoms. The results indicate that pilG has a role in X. fastidiosa virulence in grapevines. 相似文献
19.
R. Lebecka 《European journal of plant pathology / European Foundation for Plant Pathology》2009,124(2):345-348
Solanum nigrum, black nightshade, is a wild non-tuber bearing hexaploid species with a high level of resistance to Phytophthora infestans (Colon et al. 1993), the causal agent of potato late blight, the most devastating disease in potato production. However, the genetic mode of
resistance in S. nigrum is still poorly understood. In the present study, two S. nigrum accessions, 984750019 (N19) and #13, resistant (R) and susceptible (S), respectively, to three different isolates of P. infestans, were sexually crossed. The various kinds of progeny including F1, F2, F3, and backcross populations (BC1; F1 × S), as well as two populations produced by self-pollinating the R parent and S parent, were each screened for susceptibility
to P. infestans isolate MP 324 using detached leaf assays. Fifty seedling plant individuals of the F1 progeny were each resistant to this
specific isolate, similarly to the seedling plants resulting from self-pollination of the resistant R parent. Thirty seedling
plants obtained from self-pollination of the S parent were susceptible. Among a total of 180 F2 plants, the segregation ratio
between resistant and susceptible plants was approximately 3: 1. Among the 66 seedling plants of the BC1 progeny originating from crossing an F1 plant with the susceptible S parent, there were 26 susceptible and 40 resistant plants
to P. infestans. The segregation patterns obtained indicated monogenic dominant inheritance of resistance to P. infestans isolate MP 324 in S. nigrum acc. 984750019. This gene, conferring resistance to P. infestans, may be useful for the transformation of potato cultivars susceptible to late blight. 相似文献
20.
Aparana Srivastava Sonali Trivedi Sunil Kumar Krishna H. N. Verma Vivek Prasad 《European journal of plant pathology / European Foundation for Plant Pathology》2009,123(2):241-246
CAP-34, a protein from Clerodendrum aculeatum inducing systemic antiviral resistance was evaluated for control of Papaya ringspot virus (PRSV) infection in Carica papaya. In control plants (treated with CAP-34 extraction buffer) systemic mosaic became visible around 20 days that intensified
up to 30 days in 56% plants. During this period, CAP-34-treated papaya did not show any symptoms. Between 30 and 60 days,
95% control plants exhibited symptoms ranging from mosaic to filiformy. In the treated set during the same period, symptoms
appeared in only 10% plants, but were restricted to mild mosaic. Presence of PRSV was determined in induced-resistant papaya
at the respective observation times by bioassay, plate ELISA, immunoblot and RT-PCR. Back-inoculation with sap from inoculated
resistant plants onto Chenopodium quinoa did not show presence of virus. The difference between control and treated sets was also evident in plate-ELISA and immunoblot
using antiserum raised against PRSV. PRSV RNA was not detectable in treated plants that did not show symptoms by RT-PCR. Control
plants at the same time showed a high intensity band similar to the positive control. We therefore suggest that the absence/delayed
appearance of symptoms in treated plants could be due to suppressed virus replication. 相似文献