Japanese Journal of Phytopathology
Online ISSN : 1882-0484
Print ISSN : 0031-9473
ISSN-L : 0031-9473
Volume 42 , Issue 2
Showing 1-17 articles out of 17 articles from the selected issue
  • Haruo MIURA, Masako KATAGIRI, Tomio YAMAGUCHI, Yasuhiko UESUGI, Hirosh ...
    1976 Volume 42 Issue 2 Pages 117-123
    Published: April 25, 1976
    Released: February 19, 2009
    JOURNALS FREE ACCESS
    Kasugamycin sensitivity was evaluated of 207 isolates of Pyricularia oryzae, derived from 3 fields where the antibiotic had given poor blast control and also from 3 fields where the antibiotic still remained effective. From each of the former 3 fields, resistant isolates were found together with sensitive ones, but all isolates from the latter 3 fields were sensitive to the antibiotic. Isolates from each lesion on rice plants were either all resistant or all sensitive, and in no case resistant and sensitive isolates were found together in the same lesion. The frequency distribution of kasugamycin sensitivity among the 207 isolates, as evaluated by agar diffusion method, indicated the clear distinction between resistant and sensitive strains, and no intermediate resistant strains were detected. With regard to mycelial growth on agar plates, sporulation in vitro, number and length of lesions on inoculated leaves, no significant difference was found between sensitive group and resistant group. Frequency of the resistant clones among conidia from stock cultures did not vary within the range of selection pressure from 100 to 500μg/ml kasugamycin, but varied with strains, and with culture condition. A single spore culture just before the selection test led to a low frequency of resistant conidia, suggesting that the resistant clones might have occurred at least partly, by spontaneous mutation during stock culture.
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  • C.R. REDDY, S.H. Ou
    1976 Volume 42 Issue 2 Pages 124-130
    Published: April 25, 1976
    Released: February 19, 2009
    JOURNALS FREE ACCESS
    A thorough study of physiological and biochemical characteristics of 40 isolates of Xanthomonas oryzae from Asia revealed that no distinct biochemical groups or types exist in blight pathogen, which would suggest that the isolates even from wide geographical regions are much more homogeneous in their reaction than described in literature. The present description can be considered as norms of this species in identifying it when seperated from host and also to differentiate it from other nomenspecies of Xanthomonas.
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  • Seiji OUCHI, Hachiro OKU, Hideto NAKABAYASHI, Kazunori OKA
    1976 Volume 42 Issue 2 Pages 131-137
    Published: April 25, 1976
    Released: February 19, 2009
    JOURNALS FREE ACCESS
    Effect of heat treatment on the establishment of infection and colony development of powdery mildew of barley was studied by use of an isogenic line. Percentages of spores elongating secondary hyphae, the length of secondary hyphae, colony development, and sporulation all indicated that there were three phases in the plant response to the pathogen during the treatment with increasing doses of heat. The primary phase was an induced susceptibility found at around 45C-45min. The second stage is an inhibition of once-induced susceptibility found at around 50-53C. The third phase is another induced susceptibility detected at around 50C-60sec, and is differentiated from other phases by the visible colony development. The kinetic analysis of the inhibition phase indicated that the rate of inactivation of induced susceptibility follows that of a pseudo first-order reaction. The acceptance or rejection by the host cell of the pathogen, therefore, must be an all-or-none event.
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  • TAKAO KOBAYASHI, KENICHI SATO
    1976 Volume 42 Issue 2 Pages 138-148
    Published: April 25, 1976
    Released: February 19, 2009
    JOURNALS FREE ACCESS
    The Cercospora causing brown leaf spot of Physocarpus spp. in Japan was identified as C. spiraeicola Muller et Chupp on the basis of their identical morphological characteristics. Among the inoculated plants belonging to Spiraeaceae, the fungus infected Physocarpus amurensis and P. opulifolius, but not Spiraea spp., Stephanandra spp. and Sorbaria kirilowii, even though, C. spiraeicola had been described on Spiraea prunifolia. Conidia of the fungus overwinter on the fallen diseased leaves. They keep well their germination ability throughout winter and serve as the primary infection source from May to June. Incubation period of the fungus is about two months in spring and one month in summer and early autumn. The fungus may not overwinter within winter bud on the diseased bushes. Conidia germinate and mycelial colonies grow at 10∼35C with optimum temperature of 25∼30C. They germinate well under atmospheric humidity above 98%. H-ion concentration has no influence on not only germination of conidia except pH 3, but also growth of mycelial colonies. Colonies of the fungus grow well on malt extract, potato-sucrose, Saito's soy and Waksman's solution agar.
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  • Akitoshi TAJIMI
    1976 Volume 42 Issue 2 Pages 149-155
    Published: April 25, 1976
    Released: February 19, 2009
    JOURNALS FREE ACCESS
    Genetic control of uredial development of stem rust, Puccinia graminis Pers., in orchardgrass, Dactylis glomerata L., was demonstrated in the following three experiments:
    1. Five clonal lines of orchardgrass which were presumed to be nulliplex, simplex and duplex for resistance gene to race IIc or Ic were inoculated with the two races of stem rust. Uredia were observed to develop on nulliplex and simplex plants, but not on duplex plants. Large elongated uredia, parallel to leaf vein, were observed on nulliplex plants, while small and round uredia, often surronded by chlorotic or necrotic area, were observed on simplex plants.
    2. A duplex clonal line which were duplex for resistance gene to races Ic and IIc and its immediate progenies after self-pollination were inoculated with the two races of stem rust. Genic constitutions of immediate self-pollinated progenies (S1) for resistance to stem rust were revealed by further progeny tests. Uredium development was observed on nulliplex and simplex plants but not on duplex and triplex (or quadruplex) plants. Large uredia were observed on nulliplex plants.
    3. A clonal line which was triplex for resistance gene to races IIIC and IIIW (Puccinia graminis Pers. f. sp. phlei-pratensis Stak. & Piem.), duplex for resistance gene to races IC and IIC, simplex for resistance gene to race IIT and nulliplex for resistance gene to race IIN, was inoculated with the above-mentioned six races. Uredia developed in nulliplex and simplex cases, but not in duplex and triplex cases. Large uredia were observed only on nulliplex plants.
    From the results of these experiments, it was evident that the uredial development of stem rust was under genetic control in orchardgrass. Gene dose effects on resistance were demonstrated. These results suggested possibility of estimating genotypes for resistance to stem rust from phenotypic responses to the fungus.
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  • Moo Ung CHANG, Kei ARAI, Yoji DOI, Kiyoshi YORA
    1976 Volume 42 Issue 2 Pages 156-157
    Published: April 25, 1976
    Released: February 19, 2009
    JOURNALS FREE ACCESS
    A bacilliform virus, designated orchid fleck virus (OFV), was isolated from six genera of orchid plants including Angulorea, Cymbidium, Dendrobium, Odontoglossum, Oncidium, and Pescatorea. The virus causes systemic leaf symptoms of chlorotic or necrotic flecks in orchid plants. The virus was transmitted to Dendrobium, tobacco, Nicotiana glutinosa, Chenopodium amaranticolor, and three other plants, by sap inoculation when the temperature was higher than 30C. The virus particles could be detected in preparations obtained by the modified direct negative staining method devised by the present authors. The virus was partially purified, and the preparation contained numerous virus particles and was infectious to Dendrobium plants. The virus particle is approximately 40×150nm in negatively stained preparations, but 32-35×100-140nm in thin sections. The particle had no envelope and consisted of a helical structure with a pitch of 4.5nm. In thin sections of OFV-infected tissues, a large number of virus particles were found in the nuclei and in the cytoplasm, and the viroplasm development was also observed in the nuclei of OFV-infected cells. A series of electron micrographs suggest that OFV particles are formed in the viroplasms and disperse along the membrane system into the cytoplasm after passing through the nuclear envelope. From these observations it is concluded that OFV is a virus belonging to a new virus group different from the rhabdovirus group. Dendrobium virus (Petzold, 1971), Phalaenopsis virus (Lesemann and Begtrup, 1971), ringspot virus of coffee (Kitajima and Costa, 1972) citrus leprosis virus (Kitajima and Costa, 1972) may be identical with, or closely related to, OFV.
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  • Tetsuo NAKAJIMA, Isamu YAMAGUCHI, Tomomasa MISATO
    1976 Volume 42 Issue 2 Pages 168-173
    Published: April 25, 1976
    Released: February 19, 2009
    JOURNALS FREE ACCESS
    As described in the previous paper, it is clear that the primary inhibitory site of sodium N-Lauroyl-L-valinate is the appressorial formation and hyphal growth. Experiments were conducted to examine the fungicidal activity of this compound on the metabolism of Pyricularia oryzae, i.e. protein synthesis, RNA⋅DNA synthesis, lipid synthesis, cell wall synthesis. Sodium N-Lauroyl-L-valinate inhibited strongly all the stages at 100μg/ml. On this concentration, this compound inhibited the incorporation of radioactive substrates into the cell and promoted the leakage. These results suggest that sodium N-Lauroyl-L-valinate affects the function of the cell membrane.
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  • Masao GOTO
    1976 Volume 42 Issue 2 Pages 174-180
    Published: April 25, 1976
    Released: February 19, 2009
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    The comparative ability of three phage-types of Xanthomonas citri (Hasse) Dowson, A, B, and C, to survive in diseased tissues was examined by inoculating the mixture of an equal amount of each on leaves of adult Natsudaidai (Citrus natsudaidai) and Unshu (C. unshu, variety Sugiyama) trees. The population of phage-type C was overcome by those of the phage-types A and B, and quickly decreased to an undetectable level by conventional plating methods of isolation. When inoculated singly, however, the population level of C was maintained like that of types A and B. The selective reduction of C was accelerated by serial passages through host plants. No difference was observed in the processes of phage-type selection by Natsudaidai or Unshu. Unlike the assumed host specificity of phage-type A and B to Natsudaidai and Unshu, respectively, based on the isolation frequencies in field surveys, no particular relationship was revealed between them from the view point of growth and survival in the diseased tissues. The same results were obtained when two phage-types were inoculated in combination on citrus leaves.
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  • Chizuyo KATO, Ikuzo URITANI
    1976 Volume 42 Issue 2 Pages 181-186
    Published: April 25, 1976
    Released: February 19, 2009
    JOURNALS FREE ACCESS
    Changes in carbohydrate content were examined in cut tissue and Ceratocystis fimbriata infected tissue (diseased tissue) of sweet potato. Determination of carbohydrate in various layers from the surface toward inner part indicated that starch was more decreased in diseased tissue than in cut tissue at the corresponding layers, and starch degradation was gradually low toward inner part both in cut and diseased tissues. Reducing sugars in cut tissue were increased toward inner part, while in the part near the surface of diseased tissue they were decreased. Sucrose content was nearly constant among various layers, except for a decrease in the first layer adjacent to the surface in diseased tissue incubated for 48hr. The time course analysis of changes in carbohydrate showed that carbohydrate was metabolized sequentially, i.e. reducing sugars were utilized firstly, sucrose secondly and starch thirdly. Time course patterns were affected by the storage period. Ten month-stored tissue showed a less response to cutting or infection in terms of changes in carbohydrate content than two month-stored tissue.
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  • Ed F. WICKER, Shun-ichi YOKOTA
    1976 Volume 42 Issue 2 Pages 187-191
    Published: April 25, 1976
    Released: February 19, 2009
    JOURNALS FREE ACCESS
    The sketchy history of occurrence of Cronartium stem rust of white pines in Japan and adjacent eastern Asia is reviewed. Current taxonomic problems with this group of rust are discussed and a more flexible taxonomic concept, with added consideration of physiological differences, is suggested. Some recent collections of the rust and artificial inoculations are reported.
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  • Shoichi TANAKA
    1976 Volume 42 Issue 2 Pages 192-196
    Published: April 25, 1976
    Released: February 19, 2009
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    The author carried out indexing experiments of grape viruses using four indicator plants, Mission, Baco 22A, LN-33, and Rupestris St. George, during the period, 1965 to 1970. Eleven varieties grown in Japan were proved to carry leafroll virus and five varieties to carry corky bark virus. Two varieties appeared to be infected by both viruses simultaneously. Fanleaf virus was not detected in the experimental indexing.
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  • Kouki OHTA, Hitoshi MORITA, Kisaku MORI, Masao GOTO
    1976 Volume 42 Issue 2 Pages 197-203
    Published: April 25, 1976
    Released: February 19, 2009
    JOURNALS FREE ACCESS
    A bacterial disease was found on matured lower leaves of cucumber grown under vinyl house conditions in winter of 1974. The disease rarely occurred on inmature leaves soon after unfolding. The disease usually started from leaf edges near hydathodes and quickly enlarged to form V-shaped lesions frequently surrounded by chlorotic areas. These lesions finally coalesced to form the severe blight along the whole margin of the leaf. From these symptoms, “marginal blight of cucumber” was proposed as the disease name. The cultural and biochemical characters of the pathogen were compared with those of Pseudomonas lachrymans, the pathogen of angular leaf spot of cucumber. These two bacteria differed in the important characteristics such as production of fluorecin, degree of gelatin liquefaction, levan formation, margarine hydrolysis, arginine dihydrolase reaction, potato rot, and utilization of sucrose, sorbitol and tartarate. The marginal blight pathogen was rather close to soft-rotting pseudomonads in bacteriological properties. Although the similarity was not complete, therefore, we are inclined to identify the present bacterium as a strain of Pseudomonas marginalis (Brown) Stevens based on the detailed survey of pathological, cultural and physiological characteristics. The isolates of P. lachrymans used in the study showed also some conflicts in physiological properties with the description of the type culture suggesting the presence of strains in this bacterium.
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  • Shoji KAMIMURA, Mie AKUTSU, Yukiyoshi TAKAHI
    1976 Volume 42 Issue 2 Pages 204-215
    Published: April 25, 1976
    Released: February 19, 2009
    JOURNALS FREE ACCESS
    Selective absorption of hymexazol (3-hydroxy-5-methylisoxazole, Tachigaren(R)) by organisms having a different sensitivity to the toxicant was investigated. Absorption of (3)-14C-labeled hymexazol by intact fungal cells revealed both active and passive absorption. Hymexazol was removed rapidly from aqueous solution by sensitive fungi, such as Pellicularia sasakii, Rhizoctonia solani (culture type 2, 1A and 1B), Fusarium roseum and F. oxysporm f. cucumerinum, whose growth was inhibited by the toxicant in vitro and in vivo. A group of insensitive organisms, such as Saccharomyces cerevisiae and Pseudomonus cruciviae absorbed less hymexazol. F. moniliforme and R. solani (culture type 3A and 3B), which have comparatively low sensitivities to hymexazol in vivo, absorbed less amount of the toxicant than the sensitive fungi. Washing the cells with buffer solution removed more hymexazol from insensitive fungi than sensitive fungi. The results suggested that absorption of hymexazol by fungal cells is an essential for its antimicrobial activity. The subsequent binding of hymexazol to the TCA and methanol insoluble fraction in cell constituents may be indicative of its site of action.
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  • Masao YAMADA, Shigehisa KIYOSAWA, Tomio YAMAGUCHI, Tetsuya HIRANO, Tak ...
    1976 Volume 42 Issue 2 Pages 216-219
    Published: April 25, 1976
    Released: February 19, 2009
    JOURNALS FREE ACCESS
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  • Hiroshi ISHIZAKI, Yoshiaki KURITA, Hitoshi KUNOH
    1976 Volume 42 Issue 2 Pages 220-222
    Published: April 25, 1976
    Released: February 19, 2009
    JOURNALS FREE ACCESS
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  • Ryoichi NISHIZAWA
    1976 Volume 42 Issue 2 Pages 223-227
    Published: April 25, 1976
    Released: February 19, 2009
    JOURNALS FREE ACCESS
    Surface characteristics of the crown gall of Sedum erythrostictum and Bryophyllum daigremontianum were observed under scanning electronmicroscope; namely, smooth in the former and rough in the later. Smooth surface partly lignified turning into rough with age, so that both characters would not be hereditary ones. In higher magnification, the surface of smooth galls was not always smooth, but showed irregularly wrinkled structures or incised streaks.
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  • Yuji HASUI, Kazuo MIYAIRI, Toshikatsu OKUNO, Ko SAWAI, Kenzo SAWAMURA
    1976 Volume 42 Issue 2 Pages 228-231
    Published: April 25, 1976
    Released: February 19, 2009
    JOURNALS FREE ACCESS
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