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1.
Soichiro Morita Mikiko Azuma Toshiko Aoba Hiroya Satou Kazuhiko Narisawa Teruyoshi Hashiba 《Journal of General Plant Pathology》2003,69(1):71-75
The root endophytic fungus Heteroconium chaetospira isolate OGR-3 was tested for its ability to induce systemic resistance in Chinese cabbage against bacterial leaf spot caused
by Pseudomonas syringae pv. maculicola and Alternaria leaf spot caused by Alternaria brassicae of the foliar diseases. Chinese cabbage seedlings planted in soil infested with an isolate of H. chaetospira were incubated in a growth chamber for 32 days. The first to fourth true leaves of the seedlings were challenge-inoculated
with P. syringae pv. maculicola or A. brassicae. Chinese cabbage planted in soil infested with H. chaetospira showed significant decreases in the number of lesions of bacterial leaf spot or Alternaria leaf spot when compared to the
control plants not treated with H. chaetospira. The results indicated that colonization of roots by H. chaetospira could induce systemic resistance in Chinese cabbage and reduce the incidence of bacterial leaf spot and Alternaria leaf spot.
Received: April 24, 2002 / Accepted: August 9, 2002 相似文献
2.
In May 1998 leaf spot caused by Septoria chrysanthemella was found on Aster savatieri in Kanagawa Prefecture, Japan. This is the first report of leaf spot on A. savatieri caused by S. chrysanthemella.
Received: September 13, 2002 / Accepted: October 18, 2002
Acknowledgments The authors thank Dr. T. Kobayashi, formerly of Tokyo University of Agriculture, for his advice on identifying the fungus. 相似文献
3.
4.
Hiroyuki UGA Yuki O. KOBAYASHI Kyoji HAGIWARA Yohachiro HONDA Toshihiro OMURA Takahide SASAYA 《Journal of General Plant Pathology》2002,68(4):378-381
The causative virus (isolate No. 4) of gentian (Gentiana spp.) mosaic, which had been identified previously as Clover yellow vein virus (C1YVV) on the basis of host range and serological reactions, was re-identified as Bean yellow mosaic virus (BYMV) on the basis of the nucleotide sequences of the gene for the coat protein (CP) and the 3′-noncoding region, as well
as the predicted amino acid sequence of CP.
Received 16 April 2002/ Accepted in revised form 19 June 2002 相似文献
5.
Tomoharu Kawahara Kazuhiro Toyoda Akinori Kiba Akiko Miura Takako Ohgawara Mikihiro Yamamoto Yoshishige Inagaki Yuki Ichinose Tomonori Shiraishi 《Journal of General Plant Pathology》2003,69(1):33-38
Two nucleoside triphosphatase (NTPase) cDNA clones were isolated from a cDNA library of Pisum sativum L., cv. Midoriusui. The genes encoding the cDNAs were designated PsAPY1 and PsAPY2. PsAPY1 included the N-terminal amino acid sequence of an NTPase bound to pea cell wall. The phylogenic analysis indicated that PsAPY1 belongs to an NTPase subfamily responsive to environmental stimuli and that PsAPY2 belongs to a discrete subfamily, the physiological role of which is almost unknown. The adenosine triphosphatase activity
of recombinant PsAPY1 was regulated by an elicitor and a suppressor from the pea pathogen Mycosphaerella pinodes. Based on these findings, we discuss the role of NTPases in response to biological stresses.
Received: May 27, 2002 / Accepted: July 31, 2002 相似文献
6.
Fumitoshi Yasuda Takao Kobayashi Hiroyuki Watanabe Hiroki Izawa 《Journal of General Plant Pathology》2003,69(1):29-32
In June 1996, a leaf spot disease widely occurred in Japanese persimmon (Diospyros kaki) orchards in Tottori Prefecture, Japan. The main diagnostic symptom was ring spot on the leaves and calyxes of young fruits;
in severe cases, lesions developed on more than half of the area of the leaf, resulting in early defoliation. Based on morphological
and pathological studies of the isolated fungi, it was shown that Pestalotiopsis longiseta, P. glandicola, P. acaciae, and P. crassiuscula were responsible for the diseases. These fungi, except P. longiseta, were found to be new pathogens of the disease.
Received: May 20, 2002 / Accepted: July 25, 2002 相似文献
7.
Ayumi Notsu Norio Kondo Shohei Fujita Kippei Murata Shigeo Naito 《Journal of General Plant Pathology》2003,69(1):39-41
A new race of Phytophthora vignae f. sp. adzukicola, designated race 4, is reported from central and western Hokkaido, Japan. The isolates obtained from diseased plants of a
new cultivar, cv. Syumari, which is resistant to races 1, 2, and 3, were determined to be a new race by the pathogenic reaction
on a set of differential adzuki bean cultivars (cv. Erimo-shozu, cv. Kotobuki-shozu, cv. Noto-shozu, cv. Urasa-shimane, and
cv. Syumari).
Received: March 7, 2002 / Accepted: August 13, 2002 相似文献
8.
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
9.
Cochliobolus miyabeanus forms a specialized infection structure, an appressorium, to infect rice. Contacting a hard surface induces appressorium
formation in C. miyabeanus, while the hydrophobicity of the substratum does not affect this morphogenic infection event. To determine whether the calcium/calmodulin-dependent
signaling system is involved in prepenetration morphogenesis in C. miyabeanus, the effects of a calcium chelator (ethylene glycol tetraacetic acid; EGTA), phospholipase C inhibitor (neomycin), intracellular
calcium channel blocker (TMB-8), calmodulin antagonists (chlorpromazine, phenoxybenzamine, and W-7), and calcineurin inhibitor
(cyclosporin A) on morphogenesis and infection were examined. Addition of Ca2+ and the calcium ionophore A23187 did not affect conidial germination, while the number of appressoria decreased with higher
concentrations. EGTA inhibited conidial germination and appressorium formation. The calcium channel blocker did not affect
appressorium formation at any concentration; however, calmodulin antagonists and the calcineurin inhibitor specifically reduced
appressorium formation at the micromolar level. One of the calmodulin antagonists, W-7, also inhibited accumulation of mRNA
of the calmodulin gene within germinating conidia and/or appressorium-forming germ tubes. Thus, biochemical processes controlled
by the calcium/calmodulin signaling system seem to be involved in the induction of prepenetration morphogenesis on rice. 相似文献
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11.
A. Muslim Hayato Horinouchi Mitsuro Hyakumachi 《Journal of General Plant Pathology》2003,69(2):143-150
Four isolates of hypovirulent binucleate Rhizoctonia (HBNR) were evaluated for their ability to control Fusarium wilt of spinach (FWS) caused by Fusarium oxysporum f. sp. spinaciae (FOS). Fourteen-day-old spinach seedlings grown in paper pots with HBNR-amended soil (1% w/w ground barley grain inoculum)
were transferred to artificially pathogen-infested soil. Treatments with HBNR isolates significantly (P = 0.05) reduced disease and discoloration severity by 56%–100% and 52%–100%, respectively. The numbers of colony-forming
units of FOS per gram fresh weight in petioles or roots were reduced significantly (P = 0.01) in the plants treated with HBNR. HBNR isolates were well reisolated from the roots inside paper pots where they were
inoculated, whereas inconsistent colonization of HBNR was recorded from the roots outside paper pots where only pathogen was
inoculated. Root extracts from HBNR-treated and pathogen-challenged plants significantly inhibited germination and germling
length of FOS. The fresh weight of spinach leaves in the HBNR-treated plants increased significantly (P = 0.01), as much as 53%–63%, over the untreated and pathogen-challenged plants. This is the first report of biocontrol of
FWS by HBNR.
Received: July 18, 2002 / Accepted: October 22, 2002
Acknowledgments We are grateful to Dr. Komada for providing nonpathogenic Fusarium F13. The senior author (A.M.) thanks the Ministry of Education, Culture, Sports, Science, and Technology (Monbukagakusho)
Japan, for financial assistance. 相似文献
12.
Wen-Hsiung Ko 《Journal of General Plant Pathology》2003,69(3):186-188
Cultures of Phytophthora cinnamomi, P. parasitica, and P. palmivora remained viable in water at room temperature for periods ranging from 6 to 23 years. The colonies that developed from the
stored cultures were thin-walled and spherical, ranging from 19.2 to 30.0 μm in diameter. The survival structures are thought
to be small chlamydospores produced in the absence of adequate nutrition and aeration.
Received: October 7, 2002 / Accepted: January 8, 2003
Acknowledgment I thank Dr. Michael L. Parsons for assistance in preparing the photograph. 相似文献
13.
Masashi Fujinaga Hideki Ogiso Nobuaki Tuchiya Hideki Saito Shigeru Yamanaka Masayuki Nozue Mineo Kojima 《Journal of General Plant Pathology》2003,69(1):23-28
Pathogenic variation among 26 Japanese isolates of Fusarium oxysporum f. sp. lactucae (FOL) was tested using 21 lettuce cultivars to select commercial lettuce cultivars as race differential indicators. Cultivar
Costa Rica No. 4 was resistant to race 1 but susceptible to race 2, consistent with the conventional standard differential
line VP1010. Cultivar Banchu Red Fire was susceptible to race 1 but resistant to race 2, which showed an opposite type of
reaction as another differential line VP1013. Cultivar Patriot was susceptible to both races. The resistance reactions of
the three cultivars under field conditions were identical with that observed in the seedlings. Thus cv. Costa Rica No. 4 and
cv. Banchu Red Fire can be used as differential hosts to identify pathogenic races of FOL. This differential system showed
that all FOL isolates obtained from diseased butterhead lettuce in Fukuoka, Japan were new races (i.e., pathogenic to three
cultivars). We propose that the new race be designated race 3. Isolates of FOL, the pathogen of Fusarium wilt in lettuce,
obtained from California showed the same reaction as that of race 1. Furthermore, the Japanese isolate SB1-1 (race 1) and
California isolate HL-2 belonged to the same vegetative compatibility group. Our results suggest that both of the fungi are
the same forma specialis.
Received: March 25, 2002 / Accepted: August 26, 2002 相似文献
14.
Inhibitors of respiration with high affinity to the Qo site of cytochrome b constitute a major class of modern agricultural fungicides. Many fungal organisms, including plant pathogens, can circumvent
this inhibition site by expressing alternative respiration, a pathway dependent on alternative oxidase and other unidentified
gene products. The restriction enzyme-mediated insertion (REMI) technique was employed in this study to disrupt genes involved
in the expression of fully functional alternative respiration of Magnaporthe grisea. In one of the REMI mutants obtained, the rescue response mediated by alternative respiration was completely abolished. In
two other mutants, the response was diminished but not entirely silenced. For all three mutants, phenotype changes were not
explained by an altered structure of the alternative oxidase gene AOXMg or by a decreased level of gene expression in response to the Qo inhibitor azoxystrobin. The gene potentially affected in
one of the REMI mutants was a homolog of the ABC1 family of genes encoding chaperone-like proteins with roles in the optimal assembly of mitochondrial membrane complexes.
Received: May 28, 2002 / Accepted: October 16, 2002
Acknowledgments The research was funded, in part, by financial support to C. Avila-Adame provided by the Fulbright-Garcia Robles Foundation,
the Institute of International Education, CONACYT-Mexico, and the Colegio de Postgraduados-Mexico. 相似文献
15.
C. Eynck B. Koopmann G. Grunewaldt-Stoecker P. Karlovsky A. von Tiedemann 《European journal of plant pathology / European Foundation for Plant Pathology》2007,118(3):259-274
The differential interactions of V. longisporum (VL) and V. dahliae (VD) on the root surface and in the root and shoot vascular system of Brassica napus were studied by confocal laser scanning microscopy (CLSM), using GFP tagging and conventional fluorescence dyes, acid fuchsin
and acridin orange. VL and VD transformants expressing sGFP were generated by Agrobacterium-mediated transformation. GFP signals were less homogenous and GFP tagging performed less satisfactory than the conventional
fluorescence staining when both were studied with CLSM. Interactions of both pathogens were largely restricted to the root
hair zone. At 24 h post-inoculation (hpi), hyphae of VL and VD were found intensely interwoven with the root hairs. Hyphae
of VL followed the root hairs towards the root surface. At 36 hpi, VL hyphae started to cover the roots with a hyphal net
strictly following the grooves of the junctions of the epidermal cells. VL started to penetrate the root epidermal cells without
any conspicuous infection structures. Subsequently, hyphae grew intracellularly and intercellularly through the root cortex
towards the central cylinder, without inducing any visible plant responses. Colonisation of the xylem vessels in the shoot
with VL was restricted to individual vessels entirely filled with mycelium and conidia, while adjacent vessels remained completely
unaffected. This may explain why no wilt symptoms occur in B. napus infected with VL. Elevated amounts of fungal DNA were detectable in the hypocotyls 14 days post-inoculation (dpi) and in
the leaves 35 dpi. Root penetration was also observed for VD, however, with no directed root surface growth and mainly an
intercellular invasion of the root tissue. In contrast to VL, VD started ample formation of conidia on the roots, and was
unable to spread systemically into the shoots. VD did not form microsclerotia in the root tissue as widely observed for VL.
This study confirms that VD is non-pathogenic on B. napus and demonstrates that non-host resistance against this fungus materializes in restriction of systemic spread rather than
inhibition of penetration. 相似文献
16.
Á. Mesterházy T. Bartók G. Kászonyi M. Varga B. Tóth J. Varga 《European journal of plant pathology / European Foundation for Plant Pathology》2005,112(3):267-281
Different sets of wheat genotypes were tested under field conditions by spraying inocula of isolates of seven Fusarium spp. and Microdochium nivale (formerly F. nivale) in the period 1998–2002. The severity of Fusarium head blight (FHB), Fusarium-damaged kernels (FDK), the yield reduction and the deoxynivalenol (DON) contamination were also measured to describe the nature of the resistance. The degrees of FHB severity of genotypes to F. graminearum, F. culmorum, F. avenaceum, F. sporotrichioides, F. poae, F.␣verticillioides, F. sambucinum and M. nivale were very similar, indicating that the resistance to F.␣graminearum was similar to that for other Fusarium spp. listed. This is an important message to breeders as the resistance relates not only to any particular isolate of F. graminearum, but similarly to isolates of other Fusarium spp. This holds true for all the parameters measured. The DON contamination refers only to DON-producers F. graminearum and F. culmorum. Highly significant correlations were found between FHB, FDK, yield loss and DON contamination. Resistance components such as resistance to kernel infection, resistance to DON and tolerance were identified in the more susceptible genotypes. As compared with western European genotypes which produced up to 700 mg kg−1 DON, the Hungarian genotypes produced only 100 mg kg−1 at a similar FDK level. This research demonstrates the importance of measuring both FDK and DON in the breeding and selection of resistant germplasm and cultivars. 相似文献
17.
Dravya, a commercially developed aqueous seaweed extract, was evaluated for its effect on the expression of symptoms of bacterial
blight caused byXanthomonas campestris pv.malvacearum (E.F. Smith) Dye in cotton. Seed soaking with Dravya (1:500) followed by foliar spray thrice at intervals of 10 days (10,
20, 30 days after sowing) resulted in a reduction in blight incidence on plants by 66%, 70% and 74% as determined 40, 60 and
80 days, respectively, after sowing. Induction of systemic resistance was associated with increases in plant height, total
number of bolls formed, boll weight, stem girth, chlorophyll content, total phenols and peroxidase activity, which intimates
that Dravya could be used as an ecofriendly potential input in the integrated management of bacterial-blight of cotton. 相似文献
18.
Mara Quaglia Antonio Zazzerini 《European journal of plant pathology / European Foundation for Plant Pathology》2007,118(4):393-400
Diaporthe helianthi the causal agent of sunflower (Helianthus annuus) stem canker, causes significant reductions in yield and oil content in most sunflower-growing areas. With the aim of enhancing
host resistance, we selected in vitro sunflower calli against culture filtrates of two pathogen isolates (7/96 and 101/96).
This technique may be an effective and rapid tool to discriminate the most virulent D. helianthi isolate and to screen for host resistance in the early stage of a breeding programme. Further investigation on the mechanisms
involved in defence pathways showed no induction of salicylic acid and pathogenesis-related proteins in calli, indicating
that the host resistance is not associated with Systemic Acquired Resistance but probably other biochemical mechanisms. 相似文献
19.
20.
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