Japanese Journal of Phytopathology
Online ISSN : 1882-0484
Print ISSN : 0031-9473
ISSN-L : 0031-9473
Volume 45 , Issue 1
Showing 1-17 articles out of 17 articles from the selected issue
  • Tomomasa YANO, A.F. PESTANA de CASTRO, James A. LAURITIS, Takao NAMEKA ...
    1979 Volume 45 Issue 1 Pages 1-8
    Published: January 25, 1979
    Released: February 19, 2009
    JOURNALS FREE ACCESS
    Thirty-one isolates belonging to 14 nomenspecies of the Xanthomonas campestris group were grouped into nine serovars by the indirect hemagglutination test.
    The isolates of Xanthomonas campestris and X. citri were serologically homogeneous. The isolates of the nomenspecies, X. cucurbitae, X. glycines, X. vesicatoria and X. vitians, exhibited serological differences within each nomenspecies. These results suggest that the indirect hemagglutination test may be a useful tool in the serological characterization of the pathovars in the Xanthomonas campestris group.
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  • Yasuo HOMMA, Yutaka ARIMOTO, Tomomasa MISATO
    1979 Volume 45 Issue 1 Pages 9-16
    Published: January 25, 1979
    Released: February 19, 2009
    JOURNALS FREE ACCESS
    Citrus melanose and citrus stem-end rot are caused by the same pathogenic fungus, Diaporthe citri (Faw.) Wolf. Melanose occurs on leaves, twigs and fruits, while stem-end rot does damage the fruit during storage. As a part of experiments on the mechanisms by which these diseases develop, the following results were obtained.
    Conidial germination was stimulated in 0.1, 1, and 10% aqueous solutions of sucrose, glucose and fructose, the main sugars of citrus.
    Germ tube elongation was greatest in a 5% solution of fructose among various concentrations of these three sugars.
    Among various pH values tested, 2.2 and 8.13 inhibited conidial germination. At any pH value, conidial germination was stimulated by addition of sugars with the order of fructose, glucose and sucrose.
    Of the aqueous solutions containing sugars or organic acids and adjusted pH values to those equivalent to the fruit sap in September, October, November and December, only the solution corresponding to September arrested conidial germination and germ tube elongation.
    Oil gland juices obtained from the exocarp of mature fruit were tested for their effect on conidial germination and on germ tube elongation at concentrations of 25, 50, 75, 80, 90 and 100%. The 90 and 100% of oil grand juice completely inhibited conidial germination but no visible effects were found at 25 and 50%.
    Inhibition of conidial germination and germ tube elongation by aceton and n-butanol extracts from pericarp suggest the presence of inhibitory substances in pericarp.
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  • Yoshio EHARA
    1979 Volume 45 Issue 1 Pages 17-24
    Published: January 25, 1979
    Released: February 19, 2009
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    The location and structural characteristics of the membranous organelles in the cells of local lesion area produced by cucumber mosaic virus (CMV) in cowpea (Vigna sinensis (L.) Endl. var. sesquipedalis; Kurodane-sanjaku) leaves were investigated by electron microscopy and compared with those of healthy cells. In the healthy tissue the membranous organells were mainly observed in the vacuole of phloem and epidermal cells, with small and simple structure. In the cells dying due to the infection, on the other hand, tubular and circinate membrane aggregations developed between the cytoplasm and the cell wall and in the vacuole. When these cells had died completely, the remnants of the membranous organelles were seen in the electron-lucent areas in the vicinity of the cell wall and in the central part. In the cells surrounding the dead cells, enlarged and complex membranous organelles containing knots of anastomosing tubules appeared mainly in the vacuole. Considering the location and changes in structure of these membranous organelles, they are assumed to play a role in excretion and a mediative role between the vacuole and cell exterior. The organelles seemed to be formed owing to invagination of plasma membrane.
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  • Koushi NISHIYAMA, Natsuki NISHIHARA, Akinori EZUKA
    1979 Volume 45 Issue 1 Pages 25-31
    Published: January 25, 1979
    Released: February 19, 2009
    JOURNALS FREE ACCESS
    A bacterial disease of ragi (Eleusine coracana), new to Japan, was found in Tochigi and Kumamoto prefectures during September 1975, and in Kagawa prefecture during August 1977. The disease occurs there usually during July to September. The affected plant shows symptom of brown stripe on the sheaths and leaf blades. Bacterial isolates from affected plants proved to be pathogenic to ragi by artifitial spray inoculation, producing similar symptoms to those produced naturally. The bacterium was also pathogenic to corn (Zea mays) and Italian millet (Setaria italica) and produced symptom of brown stripe.
    On the basis of bacteriological characteristics and pathogenicity, the tested bacterium was identified as Pseudomonas alboprecipitans Rosen 1922. P. panici, P. setariae and P. eleusineae were suggested to be synonymous with P. alboprecipitans from taxonomic considerations.
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  • Jang Kyung CHOI, Satoshi WAKIMOTO
    1979 Volume 45 Issue 1 Pages 32-39
    Published: January 25, 1979
    Released: February 19, 2009
    JOURNALS FREE ACCESS
    Polyacrylamide gel electrophoresis of the dissociated protein of turnip mosaic virus (TuMV) in the presence of sodium dodecyl sulfate (SDS) revealed three components designated as light form (LF) (MW 24, 000), middle form (MF) (MW 26, 000), and heavy form (HF) (MW 33, 000). Among them, the LF protein appeared only when TuMV purified from freezed (-21C, 7 days) leaf materials was used for protein dissociation. The MF protein, which always appeared associating with HF, was considered to be a breakdown product of the HF protein caused by proteolytic activity during storage. The HF protein behaved anomalously on SDS-polyacrylamide gel electrophoresis by using various gel concentrations. On the basis of amino acid analysis and peptide mapping, the protein subunit of TuMV, each subunit having a molecular weight of approximately 27, 500, was shown to be consisted of about 239 amino acid residues.
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  • Ikuo ITO, Tomio YAMAGUCHI
    1979 Volume 45 Issue 1 Pages 40-46
    Published: January 25, 1979
    Released: February 19, 2009
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    Resistant strains of rice blast fungus against Kasugamycin (KSM) increased population density in fields after successive use of KSM, but their density became lower year by year after a ceasing from KSM application.
    Then the behavior of sensitive and resistant strains in an infection process to rice seedlings was investigated for elucidating the cause of the decline of population density of resistant strain. Each lesion formed by a spray inoculation with a mixture of equal numbers of sensitive and resistant spores was found to consist of either the sensitive or the resistant strain alone, and the lesions colonized by resistant strains were less than those by sensitive strains. Therefore a resistant strain will have generally more inferior competitive ability in respect to infection than that of sensitive strain. There were no significant differences in the number of lesions per leaf between sensitive and resistant strains when spore suspension of each strain was separately inoculated to rice seedlings and they were kept in an incubation chamber for 24 hours, but percent infections by resistant strains were lower than that by sensitive strains when the incubation periods were 10 or 12 hours. And also the rates of appressorium formation of resistant spores after 8 hours were lower than that of sensitive spores. It seemed that the time necessary for appressorium formation and colonization by sensitive strains are shorter than that by resistant strains, and those time lag will cause inferiority of resistant strain in an infection process to rice seedlings.
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  • Akira OGOSHI, Tadao UI
    1979 Volume 45 Issue 1 Pages 47-53
    Published: January 25, 1979
    Released: February 19, 2009
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    The influence of vitamins on the growth of hyphal anastomosis groups of Rhizoctonia solani Kühn, AG-1 (IA, sasakii type), AG-1 (IB, web-blight type), AG-2-1 (winter crop type), AG-2-2 (IIIB, rush type), AG-2-2 (IV, root rot type), AG-3 (potato type), AG-4 (praticola type), and AG-5, were studied. All isolates of AG-2-2 (IIIB), AG-2-2 (IV), and AG-5 barely grew in the medium without thiamine hydrochloride, and showed 10∼20-fold growth at 10-5M thiamine, i.e. these groups are thiamine auxotrophic. The stimulating effect of thiamine was slight at 10-10M and obvious at 10-9M, and the mycelial dry weights at 10-8 or 10-7M were almost the same at 10-5M. The need for thiamine is a specific character of the group, not of the isolate. Most of AG-2-1, AG-2-2 (IIIB), AG-2-2 (IV) and AG-5 isolates had their growth somewhat stimulated with 10-5M of calcium pantothenate, but were not auxotrophic. There were two isolates of AG-2-1 that might be Ca-pantothenate auxotrophic. Some isolates had stimulated their growth with biotin, folic acid, p-aminobenzoic acid, inositol, nicotinic acid, pyridoxine hydrochloride, and riboflavin, but were not auxotrophic. The need for these vitamins is a character of the isolate, not of the group.
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  • Yoshihisa SUZUKI, Yoshiharu ODA
    1979 Volume 45 Issue 1 Pages 54-61
    Published: January 25, 1979
    Released: February 19, 2009
    JOURNALS FREE ACCESS
    Effects of blue and near ultraviolet lights on the lateral-type sclerotial development in Botrytis cinerea were studied.
    When a developing sclerotial primordium at a stage from 2 (i.e. swelled hyphae) to 3 (i.e. club-shaped hyphae) was exposed to blue light for 12-24hr, sclerotial development was inhibited. The outgrowth of club-shaped hyphae from swelled ones and further branching of club-shaped hyphae were suppressed and these sclerotial initials de-differentiated into “sterile” hyphae with sharply pointed and shrivelled tips. The inhibitory effect of blue light on the primordia at a stage from 2 to 3 could not be reversed by near ultraviolet light.
    On the other hand, when a sclerotial primordium at a stage from 1 to 3 was exposed to near ultraviolet light for a short time, the formation of conidiophores was induced on that primordium. Sclerotial development was inhibited by the predominance of conidiation over the sclerotial primordia at a stage from 1 to 2. The sclerotial development after stage 3 was no longer influenced by irradiation with near ultraviolet light, and continued normally.
    Thus, both blue and near ultraviolet lights inhibited the lateral-type sclerotial development at a definite stage of sclerotial formation, though the effects of these lights were different from each other.
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  • Takeshi OSAKI, Hirofumi KOBATAKE, Tadao INOUYE
    1979 Volume 45 Issue 1 Pages 62-69
    Published: January 25, 1979
    Released: February 19, 2009
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    A study was made of yellow vein mosaic of honeysuckle (Lonicera japonica Thunb.), characterized by yellow net symptoms which are often accompanied by enations along veins on the undersurface of the leaves.
    The disease was not mechanically transmissible, but was transmitted by a whitefly, Bemisia tabaci Gen. and by grafting the diseased plant to healthy honeysuckle and to five solanaceous species. The symptoms that appeared on some solanaceous plants were very similar to those induced by infection with tobacco leaf curl virus (TLCV). The disease was transmitted from artificially infected tomato to healthy honeysuckle which developed yellow vein mosaic indistinguishable from the original diseased honeysuckle.
    Electron microscopic examination of a partially purified virus preparation from diseased, but not from healthy leaves, showed the presence of polyhedral particles, about 18nm in diameter, that usually occurred as paired structures, 15-20×25-30nm, in negatively stained preparation. Virus-like particles were found in nuclei of phloem cells of infected tissue in ultrathin sections. The changes in the nuclei including segregation of the granular and fibrillar regions of the nucleoli and the appearance of fibrillar rings were also found.
    In agar gel diffusion tests, partially purified virus preparations from naturally infected honeysuckle reacted positively with antiserum against TLCV (NL-3 isolate), although spurs were formed with the homologous antigen. They did not react either with antisera to arabis mosaic or cucumber mosaic viruses.
    The results obtained here suggest that the causal agent of yellow vein mosaic disease of honeysuckle is a virus identical to or a strain of TLCV which is known to induce yellow dwarf disease on tomato and leaf curl disease on tobacco in Japan. An aleyrodid, Bemisia lonicerae Takahashi, a common species in Japan, is usually found on naturally grown honeysuckle and may be a vector of TLCV.
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  • Shigetou NAMBA, Shuichi YAMASHITA, Yoji DOI, Kiyoshi YORA
    1979 Volume 45 Issue 1 Pages 70-73
    Published: January 25, 1979
    Released: February 19, 2009
    JOURNALS FREE ACCESS
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  • Satoshi T. OHKI, Yoji DOI, Kiyoshi YORA
    1979 Volume 45 Issue 1 Pages 74-76
    Published: January 25, 1979
    Released: February 19, 2009
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  • 1979 Volume 45 Issue 1 Pages 77-87
    Published: January 25, 1979
    Released: February 19, 2009
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  • 1979 Volume 45 Issue 1 Pages 87-92
    Published: January 25, 1979
    Released: February 19, 2009
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  • 1979 Volume 45 Issue 1 Pages 92-97
    Published: January 25, 1979
    Released: February 19, 2009
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  • 1979 Volume 45 Issue 1 Pages 98-114
    Published: January 25, 1979
    Released: February 19, 2009
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  • 1979 Volume 45 Issue 1 Pages 114-121
    Published: January 25, 1979
    Released: February 19, 2009
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  • 1979 Volume 45 Issue 1 Pages 121-132
    Published: January 25, 1979
    Released: February 19, 2009
    JOURNALS FREE ACCESS
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