Japanese Journal of Phytopathology
Online ISSN : 1882-0484
Print ISSN : 0031-9473
ISSN-L : 0031-9473
Volume 52 , Issue 5
Showing 1-21 articles out of 21 articles from the selected issue
  • Yukio AKIYAMA, Shigeru EDA, Shigeki NISHIKAWAJI, Hiroshi TANAKA, Akio ...
    1986 Volume 52 Issue 5 Pages 741-744
    Published: December 25, 1986
    Released: February 19, 2009
    JOURNALS FREE ACCESS
    The extracellular polysaccharides produced by 17 virulent strains of Pseudomonas solanacearum collected from Japan and USA were compared in terms of wilt-inducing activity on tomato cuttings, sugar compositions, amino sugar content and degree of N-acetylation of the amino sugar. It was found that all polysaccharides investigated had wilt-inducing activity on tomato cuttings and that they were composed mainly of N-acetylgalactosamine residue.
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  • Mitsuro IWAKI, Rokuo ZENBAYASHI, Kaoru HANADA, Saburo SHIBUKAWA, Hiros ...
    1986 Volume 52 Issue 5 Pages 745-751
    Published: December 25, 1986
    Released: February 19, 2009
    JOURNALS FREE ACCESS
    In Japan, tomato plants are cultivated in the fields from spring to autumn. Mosaic disease of tomato caused by cucumber mosaic virus (CMV) is one of the most important virus diseases in these fields. A strain of CMV (CMV-SR) isolated from spinach plants showing rugose symptoms did not induce any symptoms in systemically infected tomato plants. CMV-SR was tested in the glasshouse and fields for assessing the possibility of using it as an attenuate virus in order to control the occurrence of CMV causing mosaic symptoms on tomato plants. In the glasshouse, the pre-inoculation of crude juice prepared from Nicotiana debneyi leaves infected with CMV-SR protected effectively the infection of tomato plants performed through sap inoculation of virulent CMV. The pre-inoculation of purified CMV-SR (3, 6, 30, 100 μg/ml) also controlled effectively the infection of tomato plants performed through sap inoculation and aphid transmission of virulent CMV, especially CMV-SR at a concentration of 100 μg/ml controlled nearly completely the infection. In the field experiments carried out in spring to autumn, the pre-inoculation of purified CMV-SR (100 μg/ml) markedly reduced the rate of occurrence of mosaic disease, disease index, and the rate of abnormally colored tomato fruits caused by CMV infection. The inoculation of CMV-SR did not adversely affect the growth of the tomato plants. These results indicated that CMV-SR could be used practically as an attenuate virus to control the mosaic disease caused by CMV on tomato plants.
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  • Masashi IMOTO, Mitsuro IWAKI, Hiroshi TOCHIHARA, Keiji NAKAMURA, Kaoru ...
    1986 Volume 52 Issue 5 Pages 752-757
    Published: December 25, 1986
    Released: February 19, 2009
    JOURNALS FREE ACCESS
    Brown rings on the tuber surface and internal brown arc symptoms were observed on potatoes harvested in November-December of 1980 in Hiroshima Prefecture. A virus isolated from these tubers was identified as potato mop top virus (PMTV) based on host range, symptoms induced, soil-transmissibility, particle morphology, stability in crude sap and serological relationships. PMTV-infected potato “Norin No. 1” grown at a temperature of 15 C showed yellowing or necrosis beside the leaf veins and also necrosis in netted veins. Infected tubers exhibited brown ring symptoms after twice treatments of the storage for 15 days at 18 C and 10 days at 9 C, respectively. The virus infected mechanically 13 plant species in three families (Chenopodiaceae, Aizoaceae and Solanaceae) among 45 species in 11 families. Diagnostic symptoms were produced on inoculated leaves of Chenopodium amaranticolor and Nicotiana debneyi. Soil transmission of the virus was confirmed by two different methods as follows. Potato plants “Norin No. 1” and N. debneyi grown in the soil from the fields infested with PMTV showed characteristic symptoms. N. debneyi plants were also infected through soil when planted in soil where powdery scab-infected plants to which PMTV had been mechanically inoculated were grown. Thermal inactivation point, dilution end point and longevity in vitro of the virus ranged between 65 and 70 C for 10 min, 10-2 and 2×10-3, and 5 and 7 days at 20 C, respectively. The particles were rod-shaped about 20nm in width and exhibited two peaks of 140-150 and 270-300nm in length. Antiserum obtained from rabbit immunized with the injections of the partially purified virus showed a titer of 1, 024 in immuno-electron microscopy tests. The virus also reacted positively with antiserum against PMTV from England.
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  • Meisaku KOIZUMI
    1986 Volume 52 Issue 5 Pages 758-765
    Published: December 25, 1986
    Released: February 19, 2009
    JOURNALS FREE ACCESS
    Based on the carotenoid pigmentation and the formation of kidney-shape and oval ballistospores the yeast causing pseudo greasy spot (PGS) is considered to belong to the genus Sporobolomyces. No assimilation of inositol, utilization of nitrate, absence of pseudo- or true mycelium and assimilation of soluble starch indicate that the species is Sporobolomyces roseus Kluyver et van Niel. The yeast cells multiplied on the surface of citrus leaves and some of them entered host tissues through the stomatal pores. The invading yeast cells multiplied in the intercellular spaces, but soon became immobilized and embedded with electrondense materials. The host cells adjacent to the invaded pathogens did not collapse, but their plasmalemma, tonoplast and chloroplasts degenerated.
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  • Tomohiro HORIKAWA
    1986 Volume 52 Issue 5 Pages 766-771
    Published: December 25, 1986
    Released: February 19, 2009
    JOURNALS FREE ACCESS
    Involvement of Pestalotia longiseta in the development of symptoms of tea shoot blight and the initial infection site of the fungus were investigated. When two species of tea gray blight-causing fungi, Pestalotia longiseta and P. theae were inoculated to a variety Yabukita, which is susceptible to shoot blight, only P. longiseta caused the symptoms but P. theae did not. P. longiseta did not cause shoot blight on a variety Yamakai which is resistant to the fungus. P. longiseta was isolated at a high rate from young and fresh lesions on the twigs whereas Glomerella cingulata was more frequently isolated from older and well developed lesions. When G. cingulata alone was inoculated to Yabukita, no symptoms appeared. Primary symptoms of shoot blight usually appear at the points of attachment of petioles to twigs and particularly those of scale leaves or incomplete leaves to twigs. When P. longiseta was inoculated to shoots of different growth stages in opening time of leaves, the shoots of 2 to 4-leaf stage, on which scale leaves or incomplete leaves were apt to fall off, were the most susceptible. From these results it was suggested that P. longiseta primarily infects the young shoots through the wounds made by the abscission of scale leaves or incomplete leaves and then G. cingulata secondarily colonizes in the tissue preinfected by P. longiseta expanding the lesion areas.
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  • Takashi NAIKI, Yasuhiro GONDA, Kohji KAGEYAMA
    1986 Volume 52 Issue 5 Pages 772-778
    Published: December 25, 1986
    Released: February 19, 2009
    JOURNALS FREE ACCESS
    A high correlation was found between the incidence of damping-off and the isolation frequency of Pythium species for spinach in pot experiments with spinach-field soils. Pythium species isolated from diseased spinach were classified into two groups according to their hyphal growth rates at 10 and 35 C. Based on their morphological characteristics, they were identified as Pythium paroecandrum, heretofore not reported as a cause of spinach damping-off, and P. aphanidermatum, previously reported as a cause of damping-off of spinach in the USA and Japan. Both species caused severe pre- and post-emergence damping-off of spinach in pathogenicity tests, and both were pathogenic to cucumber, pumpkin, watermelon, kidney bean and soybean.
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  • Hideo UDAGAWA, Yuichi NAKATANI, Hiroyuki WATANABE, Hiroshi OTANI, Keis ...
    1986 Volume 52 Issue 5 Pages 779-784
    Published: December 25, 1986
    Released: February 19, 2009
    JOURNALS FREE ACCESS
    The susceptible cv. Nijisseiki of Japanese pear requires fruit covers during the growing season in addition to foliar cover spray against catastrophic pests such as the black spot disease caused by Alternaria alternata Japanese pear pathotype. During 1984 summer season, the disease prevailed throughout Tottori orchards, and often caused serious fruit damages in bags without showing significant black spots on leaves and young shoots. High rate of fruit apex rotting was the main damage encountered, which was an unusual phenomenon. Pistils during blooming were found to be latently infected by pathogenic A. alternata. Removal of the colonized pistils was closely associated with a marked reduction in the rate of apex rotting of immature and fruits that were covered with protecting paper bags during the growing season. An infection model in the field using an auxotroph of the pathogen as a tracer was also investigated. When spores of choline-less mutant were inoculated carefully to stigmas during blooming with or without choline, they were able to survive dominantly on immature and growing fruits in paper-wraps more than 2 months after inoculation, even under several foliar sprays of fungicides. Spores produced on pistils occasionally caused many black spot lesions on the fruit apices due to secondary and short-ranged infection in closed paper bags, and led to severe blossom-end rotting of fruits. In black-spot-epidemic years such floral infection by the black spot pathogen may be involved in large scale damages of paper-wrapped fruits growing on trees, regardless of heavy sprays with fungicides.
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  • Tadaaki HIBI, Mitsuro IWAKI, Yasuo SAITO, Jan VERVER, Rob GOLDBACH
    1986 Volume 52 Issue 5 Pages 785-792
    Published: December 25, 1986
    Released: February 19, 2009
    JOURNALS FREE ACCESS
    The nucleic acid of soybean chlorotic mottle virus (SoyCMV) was isolated and analysed. CsCl equilibrium density gradient centrifugation and thermal denaturation kinetics revealed that the nucleic acid is a double-stranded DNA. Electrophoresis in agarose gels separated SoyCMV DNA into multiple bands, similar to those of cauliflower mosaic virus (CaMV) DNA, which indicated that this DNA consisted of both linear and circular molecules. The existence of these different topological forms was confirmed by electron microscopy. Using six different restriction endonucleases a physical map was constructed which showed the SoyCMV genome to be a circular DNA molecule of approximately 8, 200 base pairs long. The results obtained support the previous assignment of SoyCMV to the caulimovirus group.
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  • Yukio SHIRAKO, Anne K. VIDAVER, Hans-W. ACKERMANN
    1986 Volume 52 Issue 5 Pages 793-800
    Published: December 25, 1986
    Released: February 19, 2009
    JOURNALS FREE ACCESS
    Bacteriophages Clmll, ClmX and ClmXC for Clavibacter (Cl.) michiganense subsp. nebraskense were characterized with respect to biological and physical properties. All phages produced clear plaques on strain CN18-5, the original propagating host. On strain CN76-2, ClmX produced predominantly turbid plaques with a few clear plaques, from which ClmXC was derived. The host range of the three phages was restricted to strains of Cl. michiganense subsp. nebraskense. Adsorption rate constants and burst sizes of the three phages were in the range of 2.9 to 9.4×10-9ml/min and 6 to 19 virions/cell, respectively. All phages were morphologically similar with a hexagonal head about 60nm in width and a flexuous tail approximately 235nm long. The type of nucleic acid was double-stranded DNA. Agarose gel elctrophoresis of restriction endonuclease digests of the phage DNAs indicated that the three phages are similar, but distinguishable in DNA structure. C1mXC was probably a deletion mutant of ClmX.
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  • You-Liang PENG, Jiko SHISHIYAMA, Masaki YAMAMOTO
    1986 Volume 52 Issue 5 Pages 801-808
    Published: December 25, 1986
    Released: February 19, 2009
    JOURNALS FREE ACCESS
    In order to analyse the cytological aspects of interaction between rice plant and blast fungus, a new whole-leaf staining and clearing procedure has been developed, which includes following treatments of the infected tissue as bathing at 95 C in sodium chlorite solution acidified with acetic acid, dehydrating in alcohol series, staining in autoclave at 121 C with aniline blue dissolved in alcoholic lactophenol and clearing with lactophenol. In a comparative study with present procedure, acidic dyes. especially aniline blue, were found to be much more effective than basic ones to stain the infection hyphae of rice blast fungus in epidermal cells of cleared rice leaves. Acetic acid was better than hydrochloric acid for acidfying rice leaf tissue. Critical proportions of ethanol in staining solution contributed to the staining of infection hyphae and prevented rice leaf tissue from collapse by autoclaving. Staining in autoclave was effective and shortened staining time. With such superiority, this staining and clearing procedure allowed infection hyphae, even those beneath appressoria, to be easily observed and kept infected rice leaf tissue microscopically intact. This procedure should be adaptable for exactly investigating the infection behavior of rice blast fungus and the cellular reactions occurred in rice leaves during infection.
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  • Ryozo YOKOSAWA, Shiro KUNINAGA, Haruo SEKIZAKI
    1986 Volume 52 Issue 5 Pages 809-816
    Published: December 25, 1986
    Released: February 19, 2009
    JOURNALS FREE ACCESS
    Zoospores of A. euteiches were attracted to the site immediately behind the root caps of pea roots. The isolation and structural determination of attractant in pea root and its exudates were performed. Isolated attractant was 5, 4'-dihydroxy-7-methoxy-isoflavone, prunetin. This compound was detected both root and its exudates, and strongly attracted A. euteiches zoospore at the concentration 5×10-7 mol. Prunetin had no attractive effect on A. cochlioides zoospore at the concentrations 10-5-10-9 mol.
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  • Carrie R. POWELL, Wen-hsiung KO
    1986 Volume 52 Issue 5 Pages 817-824
    Published: December 25, 1986
    Released: February 19, 2009
    JOURNALS FREE ACCESS
    Among 57 species in 32 families of plants tested, root extracts from 6 species were strongly inhibitory, 4 were moderately inhibitory and 10 were weakly inhibitory to spore germination of Phytophthora palmivora. Root extract from 37 species and additional 51 unidentified plants tested were not inhibitory to P. palmivora. Root extract of garlic, the representative species of antagonistic plants selected in this study, inhibited germination of chlamydospores and encysted zoospores of P. palmivora in soil and reduced damping-off of papaya seedlings caused by this pathogen. These results indicate the possibility of finding antagonistic plants in nature which are capable of releasing antifungal substances from roots to control certain pathogens in soil.
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  • Kenichi TSUCHIYA, Tahmina AKHTER, Tomio TAKASAKI, Sumito TANAKA, Satos ...
    1986 Volume 52 Issue 5 Pages 825-834
    Published: December 25, 1986
    Released: February 19, 2009
    JOURNALS FREE ACCESS
    A new disease showing brown spot with water-soaked halo on the leaves of Cymbidium spp. occurred in Itoshima, Fukuoka, Japan during the summer in 1984. A nonfluorescent Pseudomonas sp. was consistently isolated from the infected leaves. The strains of the causal agent of the present disease were identical in being positive for the following properties: oxidase test, PHB accumulation, growth at 41 C, utilization of m-hydroxybutylate, 2, 3-butylen glycol and amylamine, and they were identical in being negative for the followings: arginine dihydrolase, nitrate reduction, denitrification, utilization of D-tartrate, itaconate and mesaconate. On the basis of their overall similarity (ca. 95%) of biochemical and nutritional tests, they were identitified as P. cepacia. These strains showed pathogenicity by inoculation to onion bulbs as well as to some orchid plants such as Cymbidium spp., Dendrobium sp. and Paphiopedilum spp. This is the first report of orchid disease caused by P. cepacia, therefore, “Bacterial brown spot disease of Cymbidium” was proposed as the name of the disease.
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  • Satoshi WAKIMOTO, Kazuyuki HIRAYAE, Kenichi TSUCHIYA, Yoshiyuki KUSHIM ...
    1986 Volume 52 Issue 5 Pages 835-842
    Published: December 25, 1986
    Released: February 19, 2009
    JOURNALS FREE ACCESS
    Plant pathogenic pseudomonads such as Pseudomonas glumae, Ps. gladioli pv. gladioli, Ps. cepacia and Ps. avenae formed growth inhibition zone around their colonies on the lawn of other plant pathogenic bacteria, Agrobaclerium tumefaciens, Corynebacterium michiganense pv. michiganense, Erwinia carotovora subsp. carotovora, Ps. solanacearum, Ps. syringae pv. syringae, Xanthomonas campestris pv. citri and X. campestris pv. oryzae, used as indicators. The activity spectra shown on the indicator bacteria were much varied depending upon the species and isolates of pseudomonads, suggesting that various antibiotic substances participated in the formation of inhibition zones.
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  • Tomoko ASAI, Tetsuro OKUNO, Kazuho MATSUURA
    1986 Volume 52 Issue 5 Pages 843-849
    Published: December 25, 1986
    Released: February 19, 2009
    JOURNALS FREE ACCESS
    Isolation and culture conditions of protoplasts from spores and hyphae of Pyricularia oryzae were studied. The combination of zymolyase and β-glucuronidase and that of driselase and cellulase were effective for the isolation of viable protoplasts from spores and hyphae of P. oryzae, respectively. A majority of protoplasts thus obtained had the potential to germinate and reverse. Protoplasts germinated in two different types. One is direct reversion to hyphae from regenerated mother cells (hyphal type germination) and another is formation of budded cells (budding type germination). The germination type of protoplasts was significantly influenced by pH and presence of agar in the medium. In Czapek-yeast extract liquid medium (CzYLM), the frequency of hyphal type germination was maximum at pH7.0. About 70% of hyphal protoplasts and about 50% of spore protoplasts germinated in direct reversion to hyphae in CzYLM at pH7.0. In contrast, the frequency of budding type germination was minimum at pH7. Presence of agar in the medium increased the frequency of hyphal type germination. The intensity of fluorescence by a calcofluor white of regenerated mother cells and budded cells increased with increase of pH of incubation medium while that of reversional hyphae was not influenced by pH. Thus we suggest that cell wall regeneration process was one of the factors involved in determination of germination type. This is the first report on the successful isolation of abundant viable protoplasts from spores of P. oryzae.
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  • Masaomi ONIKI, Katashi KOBAYASHI, Takao ARAKI, Akira OGOSHI
    1986 Volume 52 Issue 5 Pages 850-853
    Published: December 25, 1986
    Released: February 19, 2009
    JOURNALS FREE ACCESS
    In recent years, a yellow patch in turf-grass, which is probably the symptom of a new disease, has been observed in various districts of Japan. From the lesions of leaf and stem rot, binucleate Rhizoctonia was isolated and identical symptoms were reproduced in an inoculation test. The fungus did not fuse with the representative isolates of other anastomosis groups of Rhizoctonia spp. Two out of eleven isolates of this fungus developed the perfect state when the soil-on-agar culture method was applied. The perfect state of this fungus was identified as Ceratobasidium cornigerum (Bourdot) Rogers. It is proposed that this disease caused by C. cornigerum [anamorph binucleate Rhizoctonia AG-Q] would be designated as one type of ‘hagusare-byo’ of turf-grass.
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  • Shoshiro TAKEUCHI
    1986 Volume 52 Issue 5 Pages 854-857
    Published: December 25, 1986
    Released: February 19, 2009
    JOURNALS FREE ACCESS
    The following two convenient methods were devised for a successive observation of fruiting structures of intact fungi growing on artificial media. (1) Improved thin- cell-culture method: A piece of filter paper with a hole and a slit was permeated with a liquid medium and inoculated with a fungus. The preparation was held between a microscopic slide and a coverslip, and incubated at a condition favorable for fungal sporulation. Fruiting structures were observed periodically. The device was useful for light and scanning electron microscopic observation and for preparing semi-permanent mount. (2) Plastic Petri-dish method: The holes in the bottom of plastic Petri-dish were closed with coverslips, plated the agar medium, inoculated with a fungus, and incubated at a favorable condition. Microscopic observation was made through the coverslips from the bottomside of the Petri dish. This method was convenient for observation of the fruiting structures or sclerotia formed inside the medium.
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  • Tomohiro HORIKAWA
    1986 Volume 52 Issue 5 Pages 858-859
    Published: December 25, 1986
    Released: February 19, 2009
    JOURNALS FREE ACCESS
    To evaluate the resistance to benomyl of isolates of tea brown blight fungus, Glomerella cingulata, leaves and shoots infected with the fungus were collected from tea plants cultivated in three prefectures in Japan. The isolates were tested on PSA media containing fifteen concentration levels of benomyl (0.05 μg/ml-800 μg/ml). They were classified into three groups based on minimum inhibitory concentration values, i. e., resistant, intermediately resistant and susceptible isolates, whose MIC were 0.2, 12.5 and 800 μg/ml or more, respectively.
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  • Takken MATUO, Mamoru MIYAGAWA, Hideki SAITO
    1986 Volume 52 Issue 5 Pages 860-864
    Published: December 25, 1986
    Released: February 19, 2009
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  • Toru SHIMOMURA, Yuko OHASHI
    1986 Volume 52 Issue 5 Pages 865-869
    Published: December 25, 1986
    Released: February 19, 2009
    JOURNALS FREE ACCESS
    Organogermanium compound, carboxyethylgermanium sesquioxide (Ge-132), greatly inhibited the number of local lesions produced on leaves of Samsun NN tobacco inoculated with TMV. However, no remarkable inhibition of TMV multiplication in Samsun tobacco or CMV multiplication in cucumber were observed. It was apparent that Ge-132 treatment of these plants which were not inoculated with viruses, caused the leaf deformities and other symptoms resembling those of some virus diseases. In Ge-132 treated leaves, nucleic acid and protein synthesis were more effectively inhibited in ribosomal fraction than that in TMV fraction. In addition, Ge-132 was found to induce necrotic lesions on N. glutinosa leaves systemically infected with TMV at 30 C, as does actinomycin D.
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  • Yohachiro HONDA, Kaoru HANADA, Kinji USHIYAMA, Rokuo ZENBAYASHI, Hiros ...
    1986 Volume 52 Issue 5 Pages 870-873
    Published: December 25, 1986
    Released: February 19, 2009
    JOURNALS FREE ACCESS
    In 1984, alfalfa mosaic virus (AMV) was isolated from pepino (Solanum muricatum) plants showing ring spot symptoms in Kanagawa, and Hiroshima Prefectures and cucumber mosaic virus (CMV) was isolated from the plants showing mosaic symptoms in Kanagawa, Saitama and Hiroshima. Both viruses were transmitted by mechanical inoculation and by aphid. The AMVs and AMV isolated from white clover were serologically distinguished by spur formation in immunodiffusion tests. The CMVs were serologically indistinguishable from CMV-Y. Electrophoretic patterns of RNAs and coat protein of the AMVs and the CMVs were similar to those of AMV from white clover and CMV-Y, respectively.
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