Japanese Journal of Phytopathology
Online ISSN : 1882-0484
Print ISSN : 0031-9473
ISSN-L : 0031-9473
Volume 53 , Issue 5
Showing 1-15 articles out of 15 articles from the selected issue
  • Noriyuki DOKE, Toshihiro SHIBATA
    1987 Volume 53 Issue 5 Pages 577-584
    Published: December 25, 1987
    Released: February 19, 2009
    JOURNALS FREE ACCESS
    Incubation of Xanthomonas campestris pv. citri, pv. campestris, pv. pruni, and pv. vesicatoria with an extracellular O-2 generating system, xanthine-xanthine oxidase (XOD) reaction mixture, resulted in extensive death of these bacteria. However, other tested bacteria, Agrobacterium tumefaciens, Erwinia herbicola and Corynebacterium michiganense were more tolerant to the O-2 generating system. The toxicity of the O-2 generating system to each bacterium was positively correlated with sensitivity to ultraviolet light irradiation, and negatively correlated with the activity of the bacterial superoxide dismutase (SOD). Killing of X. campestris pv. citri by the O-2 generating system occurred with a linear dependency on log concentration of XOD. Exogenously added SOD partially negated the effect with a linear dependency on the log concentration. X. campestris pv. citri was also highly sensitive to methylviologen, which is known to produce superoxide in living cells. Co-injection into citrus leaves of a virulent isolate of X. campestris pv. citri together with methylviologen, at a concentration causing no host tissue damage, resulted in marked inhibition of the bacterial growth in the host leaf tissue. Co-injection with SOD and catalase restored the growth of the bacteria. A spray application of methylviologen onto citrus leaves, which was sprayed at 1, 7, and 24hr after the bacteria were inoculated by spray, protected the leaves from occurrence of citrus canker lesions.
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  • Hee Byung CHAI, Noriyuki DOKE
    1987 Volume 53 Issue 5 Pages 585-590
    Published: December 25, 1987
    Released: February 19, 2009
    JOURNALS FREE ACCESS
    Treatment of the lower three leaves of potato plants with hyphal wall components of Phytophthora infestans systemically activated in upper leaves an O-2 generating reaction from 1 to at least 7 days after treatment. In the same leaves activation of superoxide dismutase immediately followed the enhanced O-2 generating reaction. Peroxidase activity increased linearly from 3 days after treatment. In the leaves activated for O-2 generation, superoxide dismutase and peroxidase, challenge inoculation with a zoospore suspension of P. infestans caused further enhancement of the O-2 generating reaction from 1 to 5hr after inoculation. The percentage of successful penetrations by the fungi and the appearance of susceptible lesions were greatly reduced in such tissues. The systemic activation of O-2 generating reaction is discussed in relation to induction of systemic resistance.
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  • Shigehito TAKENAKA, Reiichi YOSHINO
    1987 Volume 53 Issue 5 Pages 591-597
    Published: December 25, 1987
    Released: February 19, 2009
    JOURNALS FREE ACCESS
    Ribosomes were isolated from four snow mold fungi (Pythium paddicum, P. iwayamai, Typhula incarnata and Fusarium nivale) and wheat seedlings, and their proteins were analyzed by SDS-polyacrylamide gel electrophoresis (SDS-PAGE). No difference was found in electrophoretic patterns between P. paddicum and P. iwayamai. However, there were several differences among two Pythium species, T. incarnata, F. nivale and wheat. The ribosomes were isolated also from wheat seedlings infected with P. paddicum, T. incarnata and F. nivale individually, and their proteins were analyzed by SDS-PAGE. The distinctive fungal ribosomal protein bands were detected in all patterns obtained from the infected wheat plants. The possibility of the ribosomal protein-based assay to detect snow mold fungi in wheat plants is suggested.
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  • Kazuyuki HIRATSUKA, Shigetou NAMBA, Shuichi YAMASHITA, Yoji DOI
    1987 Volume 53 Issue 5 Pages 598-605
    Published: December 25, 1987
    Released: February 19, 2009
    JOURNALS FREE ACCESS
    Properties of viruses from bamboo culm rust fungus, Stereostratum corticioides (Berk. et Br.) Magnus were investigated. S. corticioides virus (StcV) was purified by chloroform clarification, polyethylene glycol precipitation and differential centrifugations. The sucrose density gradient centrifugation yielded a single band formed by spherical viruses about 40nm in diameter. The buoyant densities of intact and empty virus particles in CsCl were about 1.39 and 1.29g/cm3, respectively. Two major capsid proteins with molecular weights of about 92, 000 and 80, 000 daltons were characterized by SDS-polyacrylamide gel electrophoresis. The viral nucleic acid was shown to be double-stranded (ds) RNA by enzymatic tests and molecular weight of the dsRNA was estimated about 3.5×106 daltons by 1% agarose gel electrophoresis. Antiserum against StcV was prepared by immunizing a rabbit. Immune electron microscopy (IEM) showed that this antiserum reacted with viruses from different origins of S. corticioides, suggesting that serologically similar viruses are widespread. On the other hand, morphologically similar viruses from Puccinia allii, P. hordei, P. miscanthi, P. recondita and Coleosporium asterum did not react with StcV antiserum. It was shown that morphologically similar but serologically distinct viruses existed among rust fungi.
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  • Masami YOSHIKAWA, Tatsuo YOKOYAMA
    1987 Volume 53 Issue 5 Pages 606-615
    Published: December 25, 1987
    Released: February 19, 2009
    JOURNALS FREE ACCESS
    Brown spots and yellow stripes were observed on leaves of Hemerocallis fulva var. kwanso at the herbal garden of Kyoto Prefectural Research Institute of Agriculture in Ayabe in the late June of 1985. In the beginning, small brown spots appeared on both sides of the leaves and then bright yellow stripes occurred and brownings expanded gradually from the leaf tips. These symptoms had been observed until mid-November. No pathogen was generally observed on diseased leaves, while acervuli composed of the tightly interwoven hyphae were formed on host plants in moist chamber. Conidiogenous cells were clavate to subcylindrical. Conidia were blastic, ellipsoidal to fusoid, hyaline, smooth, one-celled. Inoculation tests indicated that isolates were pathogenic on injured leaves of H. fulva var. kwanso, H. fulva var. disticha, and H. fulva var. fulva. An isolate from naturally infected H. fulva var. disticha showed the same pathogenicity as those from H. fulva var. kwanso. On PDA medium, single conidium isolates formed creamy and yeastlike colonies at first, then after formed white hyphae, and eventually turned dark brown to black in color. Growth on PSA medium occurred in the range from 8 to 30C and optimum growth at between 20 and 24C. Conidia formed on PDA medium were blastic, ellipsoidal to fusoid, hyaline, smooth, one-celled. Secondary conidia were formed and yeastlike growth appeared. On the basis of its morphological characteristics and pathogenicity on the plants of the genus Hemerocallis, the present fungus was identified as Aureobasidium microstictum (Bubák) W.B. Cooke, and a common name, leaf blight, was proposed.
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  • Hiroyuki YAMAMOTO, Toshikazu TANI
    1987 Volume 53 Issue 5 Pages 616-621
    Published: December 25, 1987
    Released: February 19, 2009
    JOURNALS FREE ACCESS
    The effect of high temperature stress on resistance expression was studied with oatcrown rust system by exposing oat seedlings to a high temperature after inoculation with Puccinia coronata avenae. Three oat cultivars became resistant to crown rust when incubated at 35C for 8hr at the vegetative stage of fungal development. The effect of high temperature stress disappeared by cutting of the stem prior to the heat treatment. These experimental results suggest that the effect of heat treatment on disease outbreak is through its effect on the host. The relationship of high temperature stress-induced resistance and the role of lipoxygenase isozyme in induced resistance was discussed.
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  • Manabu KUSUNOKI
    1987 Volume 53 Issue 5 Pages 622-629
    Published: December 25, 1987
    Released: February 19, 2009
    JOURNALS FREE ACCESS
    One year-old seedlings of Pinus densiflora were inoculated with pine wood nematode, Bursaphelenchus xylophilus. Tissue samples were examined under SEM and TEM. In inoculated stems, living cells of cambia, resin canals and rays began to degrade within a few days of inoculation. Severe and early degradation of the cambial zone had appeared, particularly in samples taken from the stem base. Dissolution patterns appeared in cell walls suggesting strong cellulose decomposing activity of the nematode. Systematic death of living cells in the stem base was thought to be responsible for the death of the whole seedling.
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  • Hideo NASU, Motomu HATAMOTO, Hirotaka DATE, Shintaro FUJII
    1987 Volume 53 Issue 5 Pages 630-637
    Published: December 25, 1987
    Released: February 19, 2009
    JOURNALS FREE ACCESS
    Fruit rot of Chinese white pear (Pyrus ussuriensis Maximowicz var. sinensis Kikuchi) and Japanese pear (P. serotina Rehder var. cuta Rehder) recently occurred in Okayama Prefecture. Two types of fruit rot, namely, blossom end rot and core rot were observed. The former is found on fruits of Chinese white pear ‘Lai Yang Ci Li’ of which calix end is separate from core, and the symptoms are same with that already reported on European pear. The latter is found on fruits of Japanese pear ‘Atago’ and ‘Kosui’ of which calix end is connected with core. Thus, difference of the symptom of pear fruit rot is dependent on difference of shape of calix end part of fruit. Phomopsis sp. was isolated at very high frequency from diseased lesions of affected fruits. All isolates of Phomopsis sp. obtained show pathogenicity on fruits and twigs of several cultivars of pear, and their degree of pathogenicity is as high as that of causal agent of Japanese pear canker, P. fukushii. These isolates of Phomopsis sp. are divided into two types according to their characteristics of mycelial mat grown on potato-sucrose-agar media under a light condition. One formed a plenty of aerial mycelia and induced the medium to turn red purple in color, while the other formed little amount of aerial mycelia and induced the medium to turn grey or blownish green in color. These two groups of Phomopsis sp., however, have same size of α and β conidia, and their morphology are identical with that of P. fukushii described by Tanaka and Endo, and Phomopsis sp. which is causal agent of blossom end rot of European pear described by Ikata. From these results mentioned above, it is considered that the causal agent of two types of fruit rot of pear found in Okayama Prefecture is identified to P. fukushii and fruit rot is one of the symptoms of pear canker.
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  • Kazuyuki HIRATSUKA, Shigetou NAMBA, Shuichi YAMASHITA, Yoji DOI
    1987 Volume 53 Issue 5 Pages 638-642
    Published: December 25, 1987
    Released: February 19, 2009
    JOURNALS FREE ACCESS
  • Sadato YAMAZAKI, Keizo KATSUYA
    1987 Volume 53 Issue 5 Pages 643-646
    Published: December 25, 1987
    Released: February 19, 2009
    JOURNALS FREE ACCESS
  • Takao TSUKIBOSHI, Takashi KIMIGAFUKURO, Toru SATO
    1987 Volume 53 Issue 5 Pages 647-649
    Published: December 25, 1987
    Released: February 19, 2009
    JOURNALS FREE ACCESS
  • Susumu TAKAMATSU, Takio ICHITANI
    1987 Volume 53 Issue 5 Pages 650-654
    Published: December 25, 1987
    Released: February 19, 2009
    JOURNALS FREE ACCESS
  • Toru IWANAMI, Shigetou NAMBA, Shuichi YAMASHITA, Yoji DOI, Jiro TAKAHA ...
    1987 Volume 53 Issue 5 Pages 655-658
    Published: December 25, 1987
    Released: February 19, 2009
    JOURNALS FREE ACCESS
  • Akira NAKATA, Shinsuke SANO, Sho HASHIMOTO, Koichi HAYAKAWA, Hiroaki N ...
    1987 Volume 53 Issue 5 Pages 659-662
    Published: December 25, 1987
    Released: February 19, 2009
    JOURNALS FREE ACCESS
  • Seiya TSUSHIMA, Kazunori TSUNO, Shizuo MOGI, Satoshi WAKIMOTO, Hatsuo ...
    1987 Volume 53 Issue 5 Pages 663-667
    Published: December 25, 1987
    Released: February 19, 2009
    JOURNALS FREE ACCESS
    The mode of multiplication of Pseudomonas glumae on/in the rice grains inoculated at booting stage was examined. The total population of P. glumae in the grains at heading time was less than about 107CFU/g fresh weight of grain, but it increased to 108-109CFU/g during 6 days after heading. P. glumae cells densely colonized on the surface of basal part of lodicule and inner surface of lemma were observed under the scanning electron microscope. The bacterial cells invaded into interspaces of host cells of outer epidermis and spongy parenchyma of lemma were also observed in ultra-thin sections of the diseased specimen under the transmission type electron microscope.
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