Japanese Journal of Phytopathology
Online ISSN : 1882-0484
Print ISSN : 0031-9473
ISSN-L : 0031-9473
Volume 41 , Issue 5
Showing 1-18 articles out of 18 articles from the selected issue
  • Z. HIDAKA
    1975 Volume 41 Issue 5 Pages 423-424
    Published: December 25, 1975
    Released: February 19, 2009
    JOURNALS FREE ACCESS
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  • Noriyuki DOKE, Kohei TOMIYAMA, Norio NISHIMURA, Ho Sick LEE
    1975 Volume 41 Issue 5 Pages 425-433
    Published: December 25, 1975
    Released: February 19, 2009
    JOURNALS FREE ACCESS
    Host-parasite specificity between zoospores of race 0 or race 1 of Phytophthora infestans and tuber tissues of Rishiri (R1) or Irish Cobbler (r) potatoes was examined in vitro. Proteinaceous substances in the 20, 000×g supernatant from potato tissue homogenate bound to substances in the 10, 000×g precipitate from homogenates of both race 0 and rece 1 zoospores. The binding reaction was less with Irish Cobbler than with Rishiri. The substances in host tissue which bound to substances from zoospores were found primarily in the 100, 000×g precipitate of the 20, 000×g supernatant. The binding reactions were inhibited by substances in the germination fluid or in the supernatant of homogenates of compatible zoospores. The significance of these in vitro interactions is discussed in relation to host-parasite specificity.
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  • Akinori UEYAMA, Mitsuya TSUDA
    1975 Volume 41 Issue 5 Pages 434-440
    Published: December 25, 1975
    Released: April 03, 2009
    JOURNALS FREE ACCESS
    Cochliobolus miyabeanus, perfect state of Helminthosporium oryzae, has been produced in culture by certain crosses. Media and methods for formation of the perfect state are described. In routine experiments, the authors employed Sachs agar medium plus rice straw at the constant temperature of 24C for 25-30 days. Morphological data have concurred with the original data of Ito and Kuribayashi (1927, 1931), with the one exception of the length of the ostiolar beak.
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  • P. Ranga REDDY, S.P. RAYCHAUDHURI, Y.P. RAO
    1975 Volume 41 Issue 5 Pages 441-446
    Published: December 25, 1975
    Released: February 19, 2009
    JOURNALS FREE ACCESS
    Two phage strains for Xanthomonas translucens f. sp. oryzicola, the incitant of bacterial leaf streak disease of rice have been isolated from the diseased rice leaves collected from Pantnagar (SP1) and Cuttack (SP2). The plaque size of the two phages vaired considerably and the thermal inactivation range slightly.
    Of the 15 isolates of X. translucens f. sp. oryzicola only 7 isolates were susceptible to one or both of the phage strains, which were classified into 3 lysotypes. The phage strain SP1 lysed 19 out of 30 isolates of X. oryzae tested whereas SP2 lysed X. corchori and X. amorphophalli only.
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  • Mitsuya TSUDA, Akinori UEYAMA
    1975 Volume 41 Issue 5 Pages 447-452
    Published: December 25, 1975
    Released: February 19, 2009
    JOURNALS FREE ACCESS
    The optimum culture conditions for pseudothecia formation by Cochliobolus miyabeanus have been determined: Sachs medium with rice straw, 20-24C (development was slower at 20C), pH4.65-8.10 (in the case of Czapek's agar-no carbon source medium with rice straw: pH3.7-5.9), Sachs medium with gramineous crop or weed plants added showed fairy good pseudothecia fromation as well as with rice straw. As a natural medium for perfect state formation, rice straw decoction agar (50g, 10g, or 1g/l) or potato decoction agar (150g, 30g, or 3g/l) was adequate when a rice straw was placed on the agar surface. Use of rice seed coats on Sachs medium gave scanty pseudothecia formation.
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  • Seiji OUCHI, Hachiro OKU, Hideto NAKABAYASHI, Kazunori OKA
    1975 Volume 41 Issue 5 Pages 453-460
    Published: December 25, 1975
    Released: February 19, 2009
    JOURNALS FREE ACCESS
    Heat predisposition effects were studied of barley powdery mildew by use of some compatible and incompatible combinations. Heat treatment above 45C rendered barley leaves susceptible to incompatible races, although the pattern of dose-responses differed from one combination to the other. Treatment at 50C suggested that the once-induced susceptibility is reduced by exposing leaves for longer time. Incompatible and nonpathogenic races established infection on heat-treated leaves with much higher efficiency comparing with compatible one, but never reached the level of the compatible race in terms of ESH frequency, suggesting that these races induce rejection reaction prior to the elongation of secondary hyphae. The heat-induced susceptibility disappeared about 24hr after heat treatment at the rate of a pseudo first-order reaction. Compatible combination is also affected by heat treatment, as was illustrated in significant increase of ESH frequency by the treatment at 45C and a retreat at 50C-min.
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  • Tsutomu MATSUMOTO, Eiji OKUHARA, Toshihiro SENBOKU, Eishiro SHIKATA
    1975 Volume 41 Issue 5 Pages 461-466
    Published: December 25, 1975
    Released: February 19, 2009
    JOURNALS FREE ACCESS
    In a quantitative complement fixation test, antisera of rabbits immunized with complexes of PolyA·PolyU and methylated bovine serum albumin (MBSA), or with those of PolyI·PolyC and MBSA, which had been shown to react specifically with double-stranded RNA, were allowed to react with two kinds of bulk nucleic acids from the rice dwarf virus (RDV)-infected rice plants and from the healthy rice plants. The reactivity with the healthy rice plant-samples was very weak but in the infected rice plant-samples sixty-sixfold greater reactivity was found. To ascertain whether the reactive material in the infected rice plant-samples was RDV-RNA, both bulk nucleic acids from the healthy and the infected rice plants were fractionated by methylated albumin kieselguhr (MAK) column chromatography into RDV-RNA, tRNA, rRNA and DNA, and then the reactivity of each fraction was examined. Most of the reactivity was observed with RDV-RNA fraction.
    Thus the immunological method was demonstrated to be a useful tool for detection of RDV-RNA even in the presence of a great excess of other nucleic acid forms in the RDV-infected rice plants.
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  • Hiroshi OTANI, Syoyo NISHIMURA, Keisuke KOHMOTO, Kiyoshi YANO, Takeji ...
    1975 Volume 41 Issue 5 Pages 467-476
    Published: December 25, 1975
    Released: February 19, 2009
    JOURNALS FREE ACCESS
    Spore germination, mycelial growth and appressorial formation of Alternaria kikuchiana were similar on both susceptible and resistant Japanese pear leaves. A hostspecific toxin (AK-toxin) was synthesized and released from virulent spores immediately after germination. Four hr after inoculation, one germinating spore produced approximately 10-6μg toxin, which was capable of disturbing the metabolic activities of approximately 100 host cells. The first physiological event induced by germinating spore was an increased loss of electrolytes from susceptible leaves. This reaction was evident 2-6hr after inoculation, indicating that the leakage was caused by AK-toxin from germinating spores prior to invasion. Penetration of epidermal cells was detected only in susceptible leavers 8-12hr after inoculation with virulent spores. Hyphal growth was observed in the mesophyll tissues by 24hr. Similar infection occurred on susceptible tissues when an avirulent isolate plus AK-toxin were used. It was found that citrinin exhibited similar host specificity and toxic behaviors on Japanese pear tissues. However, spores of Penicillium citrinum, which is a citrinin producer, was unsuccessful in invading pear leaves. A possible reason for this was the fact that citrinin can be produced only from the growing mycelia and not from the germinating spores. All these data suggest that AK-toxin from germinating spores prior to host invasion plays key role as an initial inciting agent of the disease establishment.
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  • Hideki NAITO, Shigeyasu AKAI, Yukio KOSHIMIZU
    1975 Volume 41 Issue 5 Pages 477-491
    Published: December 25, 1975
    Released: April 03, 2009
    JOURNALS FREE ACCESS
    The present paper reports the mode of infection of rice leaves by the Fusarium leaf spot fungus, especially the relation between conidial fusion and invasion behaviour.
    Many of the conidia inoculated on the surface of rice leaves fused with each other by means of germtubes or projections and growth of many vigorous hyphae occurred before invasion. Invasion into rice leaves mostly took place by the vigorous superficial hyphae.
    In order to observe the details of the conidial behaviour before invasion into leaves, epidermal strips of onion bulb scales, which were floated on water in petri dish after immersing in alcohol and washing in water, were used. Inoculated conidia fused with each other and formed a conidial complex. The hyphae growing out from the conidial complex were vigorous while the hyphae or germtubes from single conidia, which were small in size, were short and slender. Penetration into the onion epidermal cells mostly took place by the vigorous superficial hyphae. Some of the conidia forming a conidial complex lost the contents entirely or partially. It appears that the contents of some conidia is translocated through the connecting hyphae to some other conidia, from which vigorous hyphae develop.
    The observations using onion epidermal strips suggest that a conidial complex acts as a unit in invasion behaviour, and vigorous hyphae on rice leaves grow utilizing the contents of conidia in the complex. Namely, the conidial fusion may be necessary for the fungus to invade into the leaves.
    The vigorous hyphae from the conidial complex, coming in contact with stomata, formed appressorium-like structures with various sizes. From the structures infection hyphae developed passing through stomatal slits and swelling in substomatal cavities. The substomatal hyphae grew profusely into the intercellular spaces and then entered mesophyll cells. The development of hyphae in vascular bundles and epidermal cells was poor. About three days after inoculation short branched conidiophores grew out through stomatal slits to form spore lumps.
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  • Chang KYU KIM, Reiichi YOSHINO, Shizuo MOGI
    1975 Volume 41 Issue 5 Pages 492-499
    Published: December 25, 1975
    Released: February 19, 2009
    JOURNALS FREE ACCESS
    Experiments in order to know the possibility of leaf blast forecasting by investigation of the number of trapped spores and the wetting period of leaves were conducted. The number of spores which was presumed to penetrate into leaves was calculated from the following equation by investigating the number of trapped spores, wetting period of leaves, leaf area, plant height and wind velocity in the experimental field.
    PSN=DSN×RA×MIP×RI
    DSN=CSN×C×LA/GA
    PSN: The number of spores which was presumed to penetrate into leaves
    DSN: The number of spores which was presumed to deposit on leaves
    RA: The rate of spores which formed appressoria
    MIP: The maximum rate of appressoria which succeeded in penetration under the most favourable condition
    RI: The ratio of penetrated appressoria to MIP in each day which was calculated by using the wetting period of leaves and the mean temperature during the wetting period
    CSN: The number of trapped spores was corrected corresponding to wind velocity and plant height
    C: Correction coefficient
    LA: Leaf area
    GA: Cover glass area
    As a result of calculation, the largest number of spores which was presumed to penetrate into leaves per plant was 3.95 on July 26 and the next was 3.70 on June 29. On July 23 the largest number of spores trapped in the period of investigation, however, the number of spores which presumed to succeed in penetration was only 0.85.
    The numbers of lesions which were estimated by adding PSN in order of date almost coincided with the numbers of lesions occurred actually in the experimental field.
    These facts indicate that the degree of leaf blast severity can be forecasted one week before lesion appearance by investigating the number of trapped spores and the wetting period of leaves.
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  • Tomio YAMAGUCHI, Ikuo ITO
    1975 Volume 41 Issue 5 Pages 500-501
    Published: December 25, 1975
    Released: February 19, 2009
    JOURNALS FREE ACCESS
    Spray inoculation with water suspension of conidia of Fusarium leaf spot fungus (Fusarium nivale (Fries) Cesati) was unsucceessful. However, the conidial germination and fusion of their germ tubes by which stomatal penetration was conducted were enormously promoted by the addition of polypeptone to spore suspension. Inoculation was accomplished by spraying spore suspensions containing 1% polypeptone and the inoculated plants were incubated in a high humidity chamber at 25-28C for more than 36 hours.
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  • Takeshi TANIGUCHI, Haruzo HIGUCHI, Masao FUKUDA
    1975 Volume 41 Issue 5 Pages 502-503
    Published: December 25, 1975
    Released: February 19, 2009
    JOURNALS FREE ACCESS
    By passing juice from chrysanthemum leaves with mosaic or mottle symptom through a Sepharose 2B gel filtration column, fractions which gave infections on Chenopodium amaranticolor, zinnia, tobacco (Samsun NN and Bright Yellow) and Nicotiana glutionsa were recovered, whereas the unfiltrated juice was noninfectious. This recovery of fraction with infectivity was due to the elimination of several inhibitors in chrysanthemum by the chromatography.
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  • Aki TOOYAMA
    1975 Volume 41 Issue 5 Pages 504-505
    Published: December 25, 1975
    Released: February 19, 2009
    JOURNALS FREE ACCESS
    Philodendron verrucosum Mattieu was shown to be a good local lesion host for dasheen mosaic virus. Other six Philodendron species so far tested were systemically infected with the virus, showing distinct mosaic symptoms. Anthurium scandens var. violaceum showed faint mottling of the leaves.
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  • Aki TOOYAMA
    1975 Volume 41 Issue 5 Pages 506-507
    Published: December 25, 1975
    Released: February 19, 2009
    JOURNALS FREE ACCESS
    Expression of mosaic symptoms on young taro plants (Colocasia esculenta (L.) Schott) from dasheen mosaic virus infected corms was promoted by root cutting or high soil temperature (40C) at sprouting stage. Under field condition the percentage of taro plants showing mosaic symptoms was highest at the beginning of July, then decreased, and increased again after the end of August.
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  • Satoshi T. OHKI, Yoji DOI, Kiyoshi YORA
    1975 Volume 41 Issue 5 Pages 508-510
    Published: December 25, 1975
    Released: April 03, 2009
    JOURNALS FREE ACCESS
    Small spherical virus particles were found in the phloem cells of broad bean plants infected with milk-vetch dwarf virus. The virus particles appear in the degenerated cytoplasm or in the vacuoles, forming amorphous, sometimes crystalline, aggregates. The virus particles could be partially purified by chloroform-butanol clarification followed by differential centrifugation. Their particle size is approximately 26nm in negatively stained preparations.
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  • Kimiharu INAGAKI, Makoto MAKINO
    1975 Volume 41 Issue 5 Pages 511-512
    Published: December 25, 1975
    Released: February 19, 2009
    JOURNALS FREE ACCESS
    Rhizoctonia oryzae Ryker et Gooch, rice sheath spot fungus, grows little on the synthetic media consisted of inorganic compounds and glucose, but well by addition of rice decoction. Hyphal growth is promoted if thiamine hydrochloride was added in the synthetic liquid medium. Growth of the fungus is still more promoted by both thiamine hydrochloride and pyridoxine hydrochloride.
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  • Akio TANII, Jun AKAI
    1975 Volume 41 Issue 5 Pages 513-517
    Published: December 25, 1975
    Released: April 03, 2009
    JOURNALS FREE ACCESS
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  • Wayne C. RICHARDS, Shozo TAKAI
    1975 Volume 41 Issue 5 Pages 518-520
    Published: December 25, 1975
    Released: February 19, 2009
    JOURNALS FREE ACCESS
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