Japanese Journal of Phytopathology
Online ISSN : 1882-0484
Print ISSN : 0031-9473
ISSN-L : 0031-9473
Volume 44 , Issue 1
Showing 1-15 articles out of 15 articles from the selected issue
  • Fumiyoshi FUKUMOTO, Hiroshi TOCHIHARA
    1978 Volume 44 Issue 1 Pages 1-5
    Published: January 25, 1978
    Released: February 19, 2009
    JOURNALS FREE ACCESS
    A virus was isolated from chinese yam plants (Dioscorea Batatas Decne. f. typica Makino) showing symptoms of chlorotic spots, necrotic spots or netted patterns of necrosis. The virus was easily transmitted by two aphids, Myzus persicae and Aphis gossypii, in a non-persistent manner, but was not transmitted with crude sap. However, the virus was found to be sap transmissible when the homogenate of frozen diseased leaves in phosphate buffer containing 0.1% thioglycollic acid or the suspension of 94, 000×g sediment of diseased leaf homogenate prepared in the presence of reducing agents was used as an inoculum. The virus particles were filamentous, approximately 12-13×660nm in size. Host range of the virus was restricted to Dioscorea spp. (D. Batatas f. typica, D. Batatas f. Tsukune and D. Batatas f. flabellata). The new virus was named chinese yam necrotic mosaic virus. The morphology and aphid transmissibility of the virus suggested that it may most probably belong to the carlavirus group.
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  • Akira MORITA
    1978 Volume 44 Issue 1 Pages 6-13
    Published: January 25, 1978
    Released: February 19, 2009
    JOURNALS FREE ACCESS
    One hundred and nine isolates of Pseudomonas eriobotryae (Takimoto) Dowson from canker infected loquat plants (Eriobotrya japonica Lind.) collected from various localities of Japan were classified into three strains on the basis of their pigment producibility on PSA medium and pathogenicity to leaves (mesophyll) of loquat plant as follows: Strain A: Pigment not produced and not pathogenic to leaves. Strain B: Pigment not produced and pathogenic to leaves. Strain C: Pigment produced and not pathogenic to leaves. The three strains differed each other in their distribution patterns corresponding with loquat cultivars. Strains A and C were widely distributed in Japan, while strain B was isolated only from leaves of the cultivar Mogi intensively cultivated in Nagasaki Prefecture. From the results of needle-prick inoculation tests, it was elucidated that the pethogenicity of each strain seems to be correlated with its origin. Strains A and C were pathogenic only to twig of both cultivars, Mogi and Tanaka, and in general, the former was more virulent to the cultivar Mogi than to Tanaka while the latter did in the opposite way. Strain B was pathogenic to twigs and leaves of both cultivars, showing a higher virulence to the cultivar Mogi.
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  • Jang Kyung CHOI, Takanori MAEDA, Satoshi WAKIMOTO
    1978 Volume 44 Issue 1 Pages 14-21
    Published: January 25, 1978
    Released: February 19, 2009
    JOURNALS FREE ACCESS
    The sensitivities of some serological methods such as tube precipitin, ring interface, bentonite flocculation and agar gel immunodiffusion tests were compared by using antiserum prepared with purified turnip mosaic virus (TuMV) and various antigen preparations of the virus. When crude sap from infected plants or partially purified virus preparation was used as an antigen, the tube precipitin, ring interface and bentonite flocculation tests showed almost similar sensitivities. When purified TuMV or its degraded protein was used, however, the sensitivity of bentonite flocculation test was remarkably high as compared to other methods. In agar gel immunodiffusion test, intact virus antigen did not react with antiserum. In order to prepare TuMV antigen useful for immunodiffusion test, the purified virus preparations were subjected to ultrasonication or chemical degradation. When the virus suspensions were sonicated for various periods, both mean length of the particles and infectivities were markedly reduced and the reduction correlated with increase of sonication period. The purified virus suspensions sonicated for periods over 1min formed single precipitin line with TuMV antiserum. With preparation sonicated for 5 to 10min, a sharp precipitin line was produced midway between the antigen and antiserum wells. TuMV proteins degraded by BaCl2, ethanolamine or pyrrolidine produced a continuous single and clear precipitin line in agar gel. BaCl2 treatment produced the highest useful amount of soluble antigen for agar gel immunodiffusion test. The products degraded by sodium dodecyl sulfate formed 2 precipitin lines; the faster-diffusing antigen was identical with those degraded with other reagents. No difference was observed in serological properties between the sonicated fragments and degraded proteins of TuMV.
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  • Isao MATSUMOTO, Tomizo OHGUCHI, Masateru INOUE, Yasuji ASADA
    1978 Volume 44 Issue 1 Pages 22-27
    Published: January 25, 1978
    Released: February 19, 2009
    JOURNALS FREE ACCESS
    Lignin was formed in cell walls of parenchyma of Japanese radish root which had been infiltrated with 700×g supernatant of homogenate of downy mildew-infected tissue. It began to form about 12 hours after infiltration of the homogenate. It was also formed to a minor extent in cell walls of root tissue infiltrated with homogenate of sliced healthy tissue. Chemical analysis of lignins extracted from both tissues showed that the lignins were probably identical. Inhibitors of nucleic acid and protein synthesis cordycepin, ethidium bromide, chromomycin A3, proflavin, actinomycin D, blasticidin S and puromycin, applied immediately after treatment with the homogenate completely inhibited lignification. When application was delayed for 30min after homogenate infiltration with the former inhibitor 2 hours with the latter, lignification was observed although the extent was reduced. These inhibitors did not affect lignification when supplied 2 or more hours after homogenate infiltration with the former and 6 or more hours with the latter, respectively. No lignin was formed in tissue which had been exposed to high temperature prior to homogenate infiltration or to anaerobic conditions after infiltration. The lignification-inducing factor contained in the homogenate was a substance which was not directly secreted by the pathogen but was indirectly formed in the diseased tissue in response to infection and/or injury.
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  • Eishiro SHIKATA, Makoto KOJIMA
    1978 Volume 44 Issue 1 Pages 28-34
    Published: January 25, 1978
    Released: February 19, 2009
    JOURNALS FREE ACCESS
    Electron microscopic detection of rod-shaped (tobacco mosaic virus) and elongated viruses (potato virus X, bean yellow mosaic and bean common mosaic viruses) by leafdip serology was carried out. Antigen antibody reaction was clearly observed when homologous antisera were used, but not when unrelated sera were used. Individual particles reacted with the specific antibodies appeared rough surface and increased their width. Aggregates of tobacco mosaic virus particles were frequently shown in the homologous antiserum mixture. Immune electron microscopic observation of small isometric viruses, such as potato leafroll and soybean dwarf viruses revealed specific clumping in homologous reaction, but not in heterologous reaction, when purified preparations of both viruses and their antibodies were mixed. The role of IgM and IgG antibodies in serological reactions of bean yellow mosaic virus and potato leafroll virus was studied by both ring interface test and immune electron microscopy. The results showed that IgG component could be responsible for the homologous reaction.
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  • Yoshio YAMADA, Kuwako NAGASHIMA, Kinji INOUE, Satoru KOJIMA
    1978 Volume 44 Issue 1 Pages 35-46
    Published: January 25, 1978
    Released: February 19, 2009
    JOURNALS FREE ACCESS
    The present scanning and transmission electron microscopy (SEM and TEM) was undertaken in an effort to clarify the uitrastructural features of mycoplasma-like organism (MLO) in phloem tissue cells of petiole, using young leaf naturally infected with mulberry dwarf. SEM revealed the three dimensionality of the fibrillar meshwork in phloem tissue cells from the diseased petiole. However, the occurrence of meshwork of this type was not seen in cells from the healthy petiole. The characteristic meshwork consisted mainly of both straight and branching filaments among which rounded bodies could be discerned. The ultrastructure of sectioned MLO corroborated in several respects the observations made by SEM. TEM of thin sections showed that both rounded and filamentous organisms were bounded only by a unit membrane and seen to contain ribosome-like particles. Thus, the fibrillar meshwork structures which are seen in the SEM may correspond to “filamentous organisms” observed by TEM. A similar structure has, to our knowledge, not been found in other vascular tissues of yellows-diseased plants. When MLO colony was observed by SEM, three basic morphological forms were seen: (1) rounded form, presumably main body, approximately 200 to 300nm in diameter, (2) elongated and irregular form, and (3) filamentous form, roughly 120nm in width, emerging from the main body. Moreover, by SEM, a better visualization of the spatial arrangement and configurations of single organisms, as well as colonies, was observed. Our results with SEM showed this MLO associated with mulberry dwarf disease to be similar in gross structural features to the cultured large-colony-forming mycoplasmas studied by this method. Details of ultrastructural features of MLO are presented.
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  • Nobuyasu OTA, Takeshi TANIGUCHI
    1978 Volume 44 Issue 1 Pages 47-51
    Published: January 25, 1978
    Released: February 19, 2009
    JOURNALS FREE ACCESS
    Inoculation of the lower leaves of Nicotiana tabacum var. Samsun NN with tobacco mosaic virus (TMV) induced resistance to challenge inoculation of TMV in the upper leaves 7 days after the primary inoculation. Development of the systemic, acquired resistance was inhibited by treatments of the inoculated leaves with blasticidin S and formycin B, but not by treatments with chleramphenicol, cycloheximide and 2-thiouracil. The inhibitory effect of blasticidin S was exhibited only when it was applied within 12hr after the primary inoculation. This suggests that de novo synthesis of mRNA or protein (s) might be associated with the development of systemic acquired resistance. Fourteen days after the primary inoculation, two newly formed protein species were found in the electrophoregrams of extracts from the inoculated and the upper uninoculated leaves. No significant change in the protein electrophoregram of the upper uninoculated leaves was observed when the lower inoculated leaves were treated with blasticidin S. This result indicates that the two protein species are not directly connected with the induction of systemic, acquired resistance.
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  • Yukio ISHIGURI, Kohei TOMIYAMA, Akio MURAI, Nobukatsu KATSUI, Tadashi ...
    1978 Volume 44 Issue 1 Pages 52-56
    Published: January 25, 1978
    Released: February 19, 2009
    JOURNALS FREE ACCESS
    Rishitin and rishitin metabolites were tested for their antifungal activities to spore germination and mycelial growth of Phytophthora infestans, and for toxicity to potato tuber tissues. The antifungal activities of rishitin-M-1 and rishitin-M-2 to races 0 and 1 of P. infestans were about one tenth that of rishitin. Treatment of tuber tissue C.V. s Rishiri, Irish cobbler and Pentland ace with rishitin caused injury and darkening of the treated tissue at about 5×10-3M, but treatments with rishitin-M-1 and rishitin-M-2 had little effect on the tuber tissue even at 10-2M, the highest concentration tested. Little difference in the toxicities to the fungi and the tuber tissue was observed between rishitin-M-2 and its epimer: (11S)- rishitin-M-2. These results suggest that metabolism of rishitin to rishitin-M-1 and rishitin-M-2 may protect the healthy potato tissue from toxic effect of accumulated rishitin. These phenomena suggest that a mechanism exist in healthy plant tissue for the detoxification of the phytoalexin.
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  • Susumu YAMANAKA, Ryoso HONKURA
    1978 Volume 44 Issue 1 Pages 57-58
    Published: January 25, 1978
    Released: February 19, 2009
    JOURNALS FREE ACCESS
    The symptoms on the rice seedlings inoculated at the budding stage of rice plant
    with “Bakanae” disease fungus, Fusarium moniliforme Sheldon, were classified to five
    types; elongation, normal growth after elongating, stunted growth after elongating,
    stunted growth, and no budding. The occurrence rate of each symptom varied
    with the different isolates used.
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  • 1978 Volume 44 Issue 1 Pages 59-66
    Published: January 25, 1978
    Released: February 19, 2009
    JOURNALS FREE ACCESS
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  • 1978 Volume 44 Issue 1 Pages 67-70
    Published: January 25, 1978
    Released: February 19, 2009
    JOURNALS FREE ACCESS
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  • 1978 Volume 44 Issue 1 Pages 70-76
    Published: January 25, 1978
    Released: February 19, 2009
    JOURNALS FREE ACCESS
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  • 1978 Volume 44 Issue 1 Pages 76-82
    Published: January 25, 1978
    Released: February 19, 2009
    JOURNALS FREE ACCESS
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  • 1978 Volume 44 Issue 1 Pages 82-100
    Published: January 25, 1978
    Released: February 19, 2009
    JOURNALS FREE ACCESS
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  • 1978 Volume 44 Issue 1 Pages 100-109
    Published: January 25, 1978
    Released: February 19, 2009
    JOURNALS FREE ACCESS
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