Japanese Journal of Phytopathology
Online ISSN : 1882-0484
Print ISSN : 0031-9473
ISSN-L : 0031-9473
Volume 57, Issue 4
Displaying 1-22 of 22 articles from this issue
  • Takuo WADA, Motohiro HIRAMATSU, Mitsuaki TAKENAKA
    1991 Volume 57 Issue 4 Pages 477-484
    Published: October 25, 1991
    Released on J-STAGE: February 19, 2009
    JOURNAL FREE ACCESS
    Pefurazoate was highly effective against major rice seed-borne diseases including “Bakanae” disease (Fusarium moniliforme), Helminthosporium leaf spot (Cochliobolus miyabeanus) and blast (Pyricularia oryzae) as a seed disinfectant. The mode of action of the compound against “Bakanae” disease was investigated with reference to relationship between deposit of the compound on and in whole seeds (unhulled rice) and translocation into grains. This fungicide was systemically active and translocated from surface of seed to its interior very rapidly, and the amount of compound translocated into grains was greatly exceeded the concentration range of MIC values against F. moniliforme. On the other hand, whole seeds and hulled rice grains were placed on PDA medium, and pathogenic fungus was isolated. From the whole seeds, the pathogenic fungus was not isolated at all, but from hulled rice grains it could be isolated with frequencies about 10%. When the paper disks containing hyphae of F. moniliforme were treated with this fungicide, the result was similar to that obtained with infected seeds. From these facts, the antifungal action of pefurazoate was considered to be fungistatic as in the case of benomyl. However, mycelia treated with pefurazoate were remarkably suppressed their growth in compared with benomyl when the paper disks were washed after soaking in the fungicides solution. The stable effect of pefurazoate was considered due to a large amount of active ingredient deposited on and in the seeds, which will act as a barrier against further developing of pathogenic fungus surviving in the grains.
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  • Akio SUMINO, Norio KONDO, Fujio KODAMA
    1991 Volume 57 Issue 4 Pages 485-491
    Published: October 25, 1991
    Released on J-STAGE: February 19, 2009
    JOURNAL FREE ACCESS
    A selective medium was developed for isolation of Pseudocercosporella herpotrichoides from soil. This medium consists of potato dextrose agar supplemented with 0.3g streptomycin sulfate and 0.8-1.0g copper sulfate per liter. On this medium P. herpotrichoides forms a characteristic reddish-brown compact colony with thick mycelium 10-14 days after inoculation. Percent recovery of P. herpotrichoides from artificially infested soil was 18-54 or 16-60% on the medium containing 800 or 1, 000ppm copper sulfate, respectively. Naturally infested field soils yielded 3, 200-38, 000 propagules of P. herpotrichoides per gram of soil.
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  • Naoto YAMAOKA, Yuhko SAKAMOTO, Takashi ITO, Issei KOBAYASHI, Hitoshi K ...
    1991 Volume 57 Issue 4 Pages 492-498
    Published: October 25, 1991
    Released on J-STAGE: February 19, 2009
    JOURNAL FREE ACCESS
    The electroporation method was applied to introduce ordinary strain of tobacco mosaic virus (TMV-OM) RNA into free cells of Brassica campestris L. cv. Komatsuna, a natural non-host plant of TMV. The infection rate of the free cells was as low as 30% when a mixture of free cells and TMV-OM RNA was electroporated. However, the rate was enhanced to about 70% when the mixture was preincubated in an ice bath for 60min prior to electroporation, demonstrating that this virus could multiply in Komatsuna cells. On the other hand, fluorescent microscopy of thin sections of Komatsuna leaves inoculated with TMV-OM revealed that this virus could multiply in inoculated leaves without any visible symptoms but did not transfer to upper leaves. Considering the fact that cauliflower mosaic virus (CaMV) can infect with a higher rate in its host plant, Komatsuna, giving a typical symptom, it is likely that the degree of transfer and/or multiplication of TMV-OM in Komatsuna tissues might be much lower than that of CaMV in some reason, or that symptom appearance might be regulated by a different mechanism from that of viral multiplication.
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  • Abdul Mannan AKANDA, Kazunori TSUNO, Satoshi WAKIMOTO
    1991 Volume 57 Issue 4 Pages 499-505
    Published: October 25, 1991
    Released on J-STAGE: February 19, 2009
    JOURNAL FREE ACCESS
    In all 21 samples of various cucurbitaceous crops showing virus disease-like symptoms were collected in 1986-87 from different locations of Bangladesh and preserved at 4°C after lyophilization or with calcium chloride. These dried samples were used for serological detection of different cucurbit-viruses, viz., cucumber mosaic virus (CMV), papaya ringspot virus (PRSV/WMV 1), watermelon mosaic virus 2 (WMV 2), zucchini yellow mosaic virus (ZYMV), cucumber green mottle mosaic virus (CGMMV) and squash mosaic virus (SqMV) by double antibody sandwich enzyme-linked immunosorbent assay (DAS-ELISA) and dot-immunobinding assay (DIBA) in 1989. Out of the 21 samples tested, two, nine, one and three were found to be positive against the antisera of CMV, PRSV, WWV 2 and SqMV, respectively. None of the samples reacted positively against the antisera of ZYMV and CGMMV. Some samples of bottlegourd, bittergourd, cucumber and pumpkin did not react with any of the antisera used.
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  • Nobuo TEZUKA, Takahiro MAKINO
    1991 Volume 57 Issue 4 Pages 506-511
    Published: October 25, 1991
    Released on J-STAGE: February 19, 2009
    JOURNAL FREE ACCESS
    Some isolates of nonpathogenic Fusarium oxysporum were isolated from the crowns of healthy strawberry plants. When strawberry plants were inoculated with the nonpathogenic F. oxysporum by dipping the roots into the spore suspension and/or adding the branculture to soils, prior to the inoculation with the pathogen (F. oxysporum f. sp. fragariae), the number of diseased strawberry plants was decreased, indicating that preinucolation of the nonpathogenic F. oxysporum suppressed the disease development of Fusarium wilt of strawberry. An isolate of nonpathogenic F. oxysporum C-8 was selected from the tested 11 isolates, all of which have some suppressive effect against the disease. The isolate C-8 was nonpathogenic to 18 plant species out of 10 families tested. The disease suppressive effect of the isolate C-8 was lost after the heat treatment (100°C, 5min) of the bran-culture. The effect was decreased remarkably, when the bran-culture was kept at room temperature for 2 years. F. oxysporum was frequently isolated from the strawberry plants 2 months after inoculation with the isolate C-8, indicating that the nonpathogenic F. oxysporum can grow in the strawberry plants. The isolate C-8 and the pathogen did not compete each other on PDA medium. It is suggested that the suppression of the disease is due to the growth of C-8 in strawberry plants reducing the infection and/or the growth of the pathogen. An isolate of nonpathogenic F. oxysporum obtained from a healthy tomato plant also had the suppressive effect against Fusarium wilt of strawberry, indicating that nonpathogenic F. oxysporum which is effective against the disease is distributing not only in strawberry, but also in other plant species. The protective effect of the isolate C-8 was demonstrated in the field when it was preinoculated, and the effect was increased when the isolate C-8 was inoculated to strawberry plants in combination with soil fumigation with methyl isothiocyanate (MITC). It is clear that the protective effect of the isolate is very high, when the density of the pathogen is low after soil sterilization with MITC.
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  • Tomio USUGI, Masaaki NAKANO, Akira SHINKAI, Takaharu HAYASHI
    1991 Volume 57 Issue 4 Pages 512-521
    Published: October 25, 1991
    Released on J-STAGE: February 19, 2009
    JOURNAL FREE ACCESS
    Three filamentous viruses were isolated from sweet potato by sap inoculation. The M-isolate infected Ipomoea spp., Nicotiana tabacum, N. benthamiana, Datura stramonium, Chenopodium quinoa, C. amaranticolor. The Mo-isolate infected Ipomoea spp., C. quinoa and C. amaranticolor. The C-isolate infected only Ipomoea spp. The infectivities of the M-, Mo- and C-isolates were lost at dilutions of 1:1, 000-1:10, 000, 1:1, 000-1:10, 000 and 1:100-1:1, 000, respectively, or after storage for one day at 20°C. The thermal inactivation points were 50-60°C, 60-70°C and 70-80°C, respectively. Virus particles of the M- and Mo-isolates were 750-810nm and 850-880nm long, respectively. The C-isolate was 710-760nm and 1, 430-1, 510nm long. The particle diameter of all isolates was 13nm. The M-isolate was easily transmitted by Myzus persicae but Mo- and C-isolates were not. The serological relationship between the M-isolate and sweet potato latent virus (SPLV) occurring in Taiwan was observed by serologically specific electron microscopy using protein A gold (SSEM-PAG). The Mo-isolate strongly reacted with antisera against sweet potato feathery mottle virus-russet crack strain (SPFMV-RC) found in the United States and SPFMV in Japan. No close serological relationship was found among three isolates. These results suggested that M- and Mo-isolates are strains of SPLV and SPFMV, respectively, and the C-isolate is a new virus, which we named sweet potato symptomless virus (SPSV).
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  • Yutaka ARIMOTO, Yasuo HOMMA, Reiichi YOSHINO, Shiro SAITO
    1991 Volume 57 Issue 4 Pages 522-525
    Published: October 25, 1991
    Released on J-STAGE: February 19, 2009
    JOURNAL FREE ACCESS
    The outbreak of leaf and panicle blast caused by Pyricularia oryzae decreased to 25% (in greenhouse) and 50% (in paddy field) on rice plants by soaking seeds in DL-alanine dodecylester hydrochloride solution (500ppm). The second and the third generation of the rice plant retained this chemically induced resistance to the disease. The blast severity reduced to 39% in greenhouse test and 48% in field test (2nd generation), and 28% in greenhouse test (3rd generation). When the chemical treatment was repeated on alternate generations of the rice seeds, the induced protection effect of DL-alanine dodecylester hydrochloride reached at high levels of 75% (original), 61% (2nd generation), 87% (3rd generation) and 97% (4th generation) of blast-preventive values. On the rice plant whose blast resistance was chemically induced, conidia of P. oryzae germinated and formed appressoria, and then its hyphae penetrated into the host tissues. However, the invading hyphae were restrained in epidermal cells and adjoining cells without subsequent penetration.
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  • Itsuo KAWAGUCHI, Noemi P. OROLAZA, Takashi TSUGE, Syoyo NISHIMURA, Nor ...
    1991 Volume 57 Issue 4 Pages 526-533
    Published: October 25, 1991
    Released on J-STAGE: February 19, 2009
    JOURNAL FREE ACCESS
    The changes in amino acid and amine contents of susceptible and resistant tomato cultivars infected with Alternaria alternata tomato pathotype or treated with its host-selective AL-toxin were investigated. AL-toxin has been known as a potential inhibitor of aspartate carbamoyltransferase (ACTase) in susceptible tomato plants. Inhibition of ACTase should result in the accumulation of aspartic acid in the susceptible plant treated with AL-toxin. In this study, however, no difference was observed in the amount of aspartic acid and other amino acids between toxin-treated and non-treated leaves of the susceptible and resistant cultivars until at least 24hr after treatment. In the susceptible tomato plants inoculated with spores at the base of the stem, amino acid contents in leaflets showing necrotic symptom were similar to that in corresponding leaflets without symptom. Aspartic acid content in symptom-developed leaflets was rather lower than that in symptom-less ones. These results do not support the hypothesis that AL-toxin inhibits ACTase. On the other hand, two amines, ethanolamine and phosphoethanolamine, markedly accumulated in susceptible tomato leaves 12 to 24hr after toxin treatment, but not in resistant ones. The increase in these amines was also observed in symptom-developing leaflets but not in symptomless ones of plants inoculated with the spores of the pathogen. These results suggest that AL-toxin induces disorder of metabolism related to these amines in susceptible tomato cells.
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  • Etsuo KIMISHIMA, Yoshinori KOBAYASHI, Takeshi NISHIO
    1991 Volume 57 Issue 4 Pages 534-539
    Published: October 25, 1991
    Released on J-STAGE: February 19, 2009
    JOURNAL FREE ACCESS
    Root rots of carnations were found in Tokyo Metropolis and Chiba Prefecture, Japan, in March of 1984 and in July of 1989, respectively. The symptoms were characterized by root rot and discoloration of stems and leaves. The pathogens obtained from Tokyo and Chiba were identified as Pythium irregulare Buisman and P. aphanidermatum (Edson) Fitzp., respectively, on the basis of their morphological and physiological characteristics. This is the first report of the disease occurrence of carnations caused by Pythium spp. in Japan.
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  • Masahiro YOSHIDA, Kenzo KOBAYASHI
    1991 Volume 57 Issue 4 Pages 540-548
    Published: October 25, 1991
    Released on J-STAGE: February 19, 2009
    JOURNAL FREE ACCESS
    The pathogenic actinomycete isolates causing root tumor of melon were characterized with morphological, cultural and physiological properties. The causal actinomycete had true mycelia, and the mycelial filaments tended to remain intact and was not fragmentary. The actinomycete did not produce sclerotia, pycnidia and sporangia, but it was characterized by formation of pseudosporangia. The spores were produced in chains on aerial mycelia. The color of mature sporulated aerial myceria was in the gray series. The spore surface was smooth, and morphology of the spore chains was retinaculum-apertum. Whole cell hydrolysates of the actinomycete contained LL-diaminopimelic acid (A2pm) but not meso-A2pm. Diagnostically important sugars were not detected. These results indicated that this causal actinomycete was belonged to cell wall type I, and to be assigned to the genus Streptomyces. The present pathogen was able to grow at the range of 15-40°C and pH 4.5-10.0, with the best growth at 27-35°C and pH 6.5-7.7. It utilized D-glucose and 13 other carbohydrates as the carbon sources but not D-mannitol, D-sorbitol, salicin and cellulose. The actinomycete was negative in melanoid pigment formation, xantine dissolution and hydrogen sulfide production, whereas it was positive in gelatin liquefaction, milk decomposition, starch hydrolysis, nitrate reduction and calcium malate dissolution. The highest concentration of NaCl to allow growth was 4%. In comparison of ten physiological characteristics and the pathogenicity to melon, there was no Streptomyces species that were identical with the present actinomycete. As the result, the actinomycete causing root tumor of melon is Streptomyces sp.
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  • Hiroyuki NAKASHIMA, Nobumichi SAKO, Keiichiro JOH, Katsuji HORI, Fukuj ...
    1991 Volume 57 Issue 4 Pages 549-557
    Published: October 25, 1991
    Released on J-STAGE: February 19, 2009
    JOURNAL FREE ACCESS
    The sequence of 1, 392 nucleotides from the 3'-terminal genomic region of aphid transmissible isolate 1 and that of 1, 103 nucleotides from the 3' region of non-transmissible isolate 31 of turnip mosaic virus (TuMV) RNA were determined. These sequences contained the complete coding region of the coat protein followed by a 3' non-coding region of 209 nucleotides. The coat protein genes of these two isolates were 864 nucleotides long, encoding 288 amino acids of Mr 33, 061 (isolate 1) or Mr 33, 132 (isolate 31). A putative glutamine-alanine cleavage site was identified at the N-termini of the coat proteins of the two isolates. Nucleotide sequence comparison of the coat protein genes of the two isolates revealed 20 nucleotide substitutions which give rise to 6 amino acid differences near the N-termini. The amino acid sequence of the coat protein of TuMV isolate 1 was 47.6 to 58.3% homologous to those of 11 other potyviruses, with most of amino acid conservation found in the C-terminal regions. The nucleotide sequence of 3' non-coding region of TuMV isolate 1 was 28.3 to 37.8% homologous to those of 11 other potyviruses.
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  • Kazutoshi MATSUO, Mitsuro KAMEYA-IWAKI, Takahiko OTA
    1991 Volume 57 Issue 4 Pages 558-567
    Published: October 25, 1991
    Released on J-STAGE: February 19, 2009
    JOURNAL FREE ACCESS
    Two different isolates of melon necrotic spot virus (MNSV), designated as MNSV-NK and MNSV-NH were isolated from infected melons in Nagasaki Prefecture. The host ranges of these isolates were restricted to the Cucurbitaceae and were similar to that of an isolate of MNSV from Shizuoka Prefecture (MNSV-S), but they produced a different type of local lesion on cotyledons of Cucumis melo L. The rates of systemic infection induced by MNSV-NK, MNSV-NH and MNSV-S in C. melo L. were 9.1%, 90.1% and 3.6%, respectively. MNSV-NK and MNSV-NH were designated as a new serotype N, because these viruses were serologically related but not identical to MNSV-S (serotype S) with double diffusion test in agar gel. All three isolates had a single coat protein with molecular weight of 41k dalton. MNSV-NK and MNSV-NH had two species of single-stranded RNAs (RNA1 and RNA2), while MNSV-S had three (RNA1, RNA2 and RNA3). Only RNA1 (MW 1.51×106) of each isolate retained pathogenicity. The origin of other RNAs was unknown yet. From these pathogenccal, serological and physical properties, three isolates were designated as NK, NH and S strains of melon nectoric spot virus.
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  • Identification of a Wound Hormone-like Substance in Melanose Spot
    Yutaka ARIMOTO, Tomihiko OHSAWA, Yasuo HOMMA
    1991 Volume 57 Issue 4 Pages 568-572
    Published: October 25, 1991
    Released on J-STAGE: February 19, 2009
    JOURNAL FREE ACCESS
    The self-defense reaction of Citrus unshiu Marc. was initiated by a response to the hyphal penetration of Diaporthe citri (Faw.) Wolf, and the melanose spot consisted of brown cells and a cork layer was formed as a result of the reaction. A series of experiments was conducted to clarify the mechanism of cork layer formation by the abnormal division of cells which occur at just under the brown cells. It was found that citrus produced cell-division inducer (CD inducer) by the self-defense reaction with infection of D. citri, and a wound hormone-like substance, CD-4 was isolated from melanose spots on fruit of C. unshiu. This substance was not detected in the healthy fruit and leaves of citrus. The wound hormone-like substance was identified as γ-amino n-butyric acid (GABA), on both physical properties and biological activity.
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  • Norio SATO, Masayasu KATO, Ahmed A. MOSA, Kiroku KOBAYASHI, Akira OGOS ...
    1991 Volume 57 Issue 4 Pages 573-576
    Published: October 25, 1991
    Released on J-STAGE: February 19, 2009
    JOURNAL FREE ACCESS
    For sample collection of blighted potato leaflets to isolate Phytophthora infestans, a sample bag of folded newspaper having several pockets was evaluated. Several blighted leaflets were separately inserted in a bag and the sample bags were incubated at from -5 to 30°C. The leaflets were dehydrated gradually and prevented from rotting by bacteria. Sample lesions were inoculated onto potato tuber slices to assess fungus viability. The lower the temperature for sample storage, the longer the viable period of P. infestans in the lesion: more than 14 days at 3°C, 5-8 days at 20°C and 1-2 days at 30°C. As the fungus was viable long enough for sample collection by mail from any district of Japan, the newspaper bag technique was practically applied with success.
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  • Jae Youl UHM, Hyung Rak SOHN
    1991 Volume 57 Issue 4 Pages 577-581
    Published: October 25, 1991
    Released on J-STAGE: February 19, 2009
    JOURNAL FREE ACCESS
  • Yoshitaka KOSAKA, Kaoru HANADA, Tsutomu FUKUNISHI, Mitsuro KAMEYA
    1991 Volume 57 Issue 4 Pages 582-586
    Published: October 25, 1991
    Released on J-STAGE: February 19, 2009
    JOURNAL FREE ACCESS
  • Jun-ichi MATSUMOTO, Satoshi T. OHKI, Tadao INOUYE
    1991 Volume 57 Issue 4 Pages 587-590
    Published: October 25, 1991
    Released on J-STAGE: February 19, 2009
    JOURNAL FREE ACCESS
  • Nobuaki MATSUYAMA
    1991 Volume 57 Issue 4 Pages 591-594
    Published: October 25, 1991
    Released on J-STAGE: February 19, 2009
    JOURNAL FREE ACCESS
  • Pissawan CHIEMSOMBAT, Akiko MURAYAMA, Masato IKEGAMI
    1991 Volume 57 Issue 4 Pages 595-597
    Published: October 25, 1991
    Released on J-STAGE: February 19, 2009
    JOURNAL FREE ACCESS
  • Norio OHTSUKA, Yasuhiko NAKAZAWA
    1991 Volume 57 Issue 4 Pages 598-602
    Published: October 25, 1991
    Released on J-STAGE: February 19, 2009
    JOURNAL FREE ACCESS
  • Unknown Factor(s) Influencing Accessibility and Inaccessibility
    Hitoshi KUNOH, Nobuya KATO, Naoto YAMAOKA, Issei KOBAYASHI
    1991 Volume 57 Issue 4 Pages 603-608
    Published: October 25, 1991
    Released on J-STAGE: February 19, 2009
    JOURNAL FREE ACCESS
  • Chaiwat TO-ANUN, Hideyoshi TOYODA, Tsutomu NISHIGUCHI, Shun-Huei CHANG ...
    1991 Volume 57 Issue 4 Pages 609-612
    Published: October 25, 1991
    Released on J-STAGE: February 19, 2009
    JOURNAL FREE ACCESS
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