Japanese Journal of Phytopathology
Online ISSN : 1882-0484
Print ISSN : 0031-9473
ISSN-L : 0031-9473
Volume 46 , Issue 1
Showing 1-17 articles out of 17 articles from the selected issue
  • Norio NISHIMURA, Kohei TOMIYAMA, Noriyuki DOKE
    1980 Volume 46 Issue 1 Pages 1-6
    Published: January 25, 1980
    Released: April 03, 2009
    JOURNALS FREE ACCESS
    The zoosporial component of Phytophthora infestans, which was previously reported to cause reduction of 3H-leucine uptake by potato tuber disks, was partially purified. Precipitate (A-fraction) was obtained by homogenizing zoospores with acetate buffer at pH 4.5 and centrifuging at 20, 000×g, and the A-fraction was suspended in borate buffer at pH 8.8, boiled for 1 hr and then centrifuged at 20, 000×g, giving the precipitate (B-fraction) and supernatant (C-fraction). Ten ml of 10 mM tris-HCl buffer containing 1 mM CaCl2 at pH 7.4 was used to suspend A and B-fraction. The buffer was used as a control. A, B and C fractions obtained from 5-6×106 zoosprores reducted uptake of 3H-leucine by the tuber disks of potato cv. Rishiri, but the inhibition rates caused by these fractions differed markedly. However, very high correlation was found between inhibition rates of 3H-leucine uptake and sugar contents of these fractions. There was no difference in the inhibition rates between the zoosporial components of incompatible and compatible races, when the activities were expressed in terms of the sugar contents. The mycelial components of P. infestans extracted by the modified method of Lisker and Kuc which was used to extract phytoalexin elicitor from that of P. infestans, also had the same effect as the zoosporial components (A, B, and C-fraction) on 3H-leucine uptake by the disks. C-fraction containing 15μg of sugar per ml sufficed to inhibit 3H-leucine uptake at the maximum rate, and the maximum rate of inhibition was attained within 2 hr after the zoosporial component (C-fraction containing 30μg sugar/ml) was administered to the disks.
    Download PDF (351K)
  • Michiharu NAKANO, Tadao INOUYE
    1980 Volume 46 Issue 1 Pages 7-14
    Published: January 25, 1980
    Released: February 19, 2009
    JOURNALS FREE ACCESS
    This paper describes the properties of burdock yellows virus, BdYV (formerly ‘Bd-F’ by Inouye and Mitsuhata, 1971), and its serological relationship to three other closteroviruses.
    BdYV induced no apparent symptoms or only faint marginal chlorosis in older leaves of infected burdock, Arctium lappa. BdYV was transmitted by the aphid, Dactynotus gobonis, in a semi-persistent manner to Callistephus chinensis, Chrysanthemum carinatum and Nicotiana clevelandii, but by sap inoculation to only N. clevelandii. The thermal inactivation point of BdYV was between 45 and 50 C and longevity in vitro was 1-2days (20 C). Ultraviolet absorption spectrum of purified preparations of BdYV was characteristic of nucleoprotein spectrum with an A 260/280 ratio of 1.73. Particles of BdYV were flexuous rods, 1700-1750×12nm, with a helical arrangement (3.6nm pitch) of the protein subunits. In ultrathin sections of infected N. clevelandii leaves, banded aggregates of virus particles as well as the characteristic vesicular structures were found in phloem cells. Necrosis of some phloem cells were also observed.
    In SDS-immunodiffusion tests with three other closteroviruses, carnation necrotic fleck (CNFV), citrus tristeza (CTV) and wheat yellow leaf (WYLV) viruses, single precipitin lines were formed in homologous antiserum-antigen combinations. BdYV produced clear precipitin line in agar gel containing 0.5% SDS, whereas the other three viruses produced in 0.1% SDS agar gel. In microprecipitin tests, positive serological relationship was observed between CNFV and WYLV.
    Download PDF (2133K)
  • Zenichi MOROMIZATO, Nobuaki MATSUYAMA, Satoshi WAKIMOTO
    1980 Volume 46 Issue 1 Pages 15-20
    Published: January 25, 1980
    Released: February 19, 2009
    JOURNALS FREE ACCESS
    Inhibitive effect of some amino acids on sclerotial formation of Rhizoctonia solani (AG-1) was tested. Few or no sclerotia were formed on sulfur containing amino acids, histidine, leucine, isoleucine, tryptophan or tyrosine amended medium. Among these amino acids, leucine was not inhibitive and was merely unuseful for the formation. Inhibitive amino acids limited sclerotium formation and affected scarcely mycelial growth. Although the structural difference between cysteine and serine or homocysteine and homoserine was small, their effects on the formation were completely reverse. Sulfur or sulfhydryl bond could be an inhibitive principle. D-isomers of stimulative amino acids inhibited the formation.
    Download PDF (292K)
  • Zenichi MOROMIZATO, Nobuaki MATSUYAMA, Satoshi WAKIMOTO
    1980 Volume 46 Issue 1 Pages 21-25
    Published: January 25, 1980
    Released: February 19, 2009
    JOURNALS FREE ACCESS
    The morphological process of sclerotium formation could be divided into 5 phases. The inhibitive effect of amino acids such as cysteine, methionine and histidine on each developmental phase was studied. The lateral branching was quite limited with the amino acids. While the aggregation of hypha was not affected. The turning from hypha to sclerotia was completely inhibited, however, this from the initials was lightly inhibited though sclerotia formed were very small. The turning from the initials only occurred at short preculturing on PDA medium. The development of whitish immatured sclerotium to pigmented matured sclerotium was also limited. The inhibition of sclerotium formation by some amino acids could be explained with the reduction of interweaving hypha caused by the inhibition of lateral branching and the limitation of cell enlargement at sclerotial maturation.
    Download PDF (1117K)
  • Nobuo TEZUKA, Yasumichi NISHI, Yasumasa WATANABE
    1980 Volume 46 Issue 1 Pages 26-33
    Published: January 25, 1980
    Released: February 19, 2009
    JOURNALS FREE ACCESS
    Procymidone [N-(3', 5'-dichlorophenyl)-1, 2-dimethyl-cyclopropane-1, 2-dicarboximide] is a potent fungicide to both thiophanate-methyl sensitive and resistant strains of Botrytis cinerea Persoon. Mutants of B. cinerea resistant to procymidone were obtained in vitro with a high frequency, when conidia or mycelia of the fungus were incubated at 25 C for 3-10 days on PSA media containing the fugicide. The minimal inhibitory concentration (MIC) value of the mutants was around 51, 200 ppm, indicating a high degree of resistance. The procymidone-resistant mutants were also resistant to iprodione, vinchlozolin and dichlozoline, showing cross-resistance among the fungicides. The mutants resistant to procymidone were obtained by plating conidia or mycelia on PSA media containing procymidone from both thiophanate-methyl sensitive and resistant strains. The latter mutants showed multiple resistance to procymidone and thiophanate-methyl. Cross-resistance between procymidone and thiophanate-methyl was not observed, which indicates the action of the two fungicides is different. Mycelial growth of the mutants resistant to procymidone on PSA media containing 100 ppm of the fungicide was similar to that on control PSA, but it was generally delayed in comparison with that of sensitive strains of wild type. Most of the mutants obtained do not produce aerial mycelia, and hyphae of the mutants spread straightly and symmetrically around the surface of PSA media. Many of the mutants produce very little conidia on PSA media, and only a few do a lot. The pathogenicity of the mutants to cucumber fruits was generally less than that of sensitive strains of wild type. Procymidone, however, was no longer effective on cucumber fruits to the mutants obtained in vitro. Competition between the mutants and sensitive strains of B. cinerea was investigated on tomato fruits. Some mutants resistant to procymidone have a superior competitive ability on tomato fruits infected by conidia or mycelia of the mutants and sensitive strains of B. cinerea in an equal proportion.
    No mutants resistant to procymidone were obtained from conidia or mycelia grown on fruits, when the fungicide was sprayed in the laboratory to the fruits of tomato, eggplant, pepper and cucumber infected by sensitive strains of wild type. Mutants resistant to the fungicide were not isolated from conidia formed on fruits, when the fungicide was used 4-7 times to the plants infected by B. cinerea in plastic houses.
    It is clear that mutants of B. cinerea resistant to procymidone were obtained in vitro by mutation with a high frequency, but it seems that the mutants resistant to the fungicide were hardly isolated in vivo or in the field.
    Download PDF (2154K)
  • Masayuki NOZUE, Kohei TOMIYAMA, Noriyuki DOKE
    1980 Volume 46 Issue 1 Pages 34-39
    Published: January 25, 1980
    Released: February 19, 2009
    JOURNALS FREE ACCESS
    Sodium azide (NaN3), 2, 4-dinitrophenol (2, 4-DNP), blasticidin S (BcS), p-chloromercuribenzoic acid (PCMB) and dextran (MW. 7×104)-bound p-chloromercuribenzoic acid (PM DT) are known to inhibit the rapid occurrence of hypersensitive death of cells infected by an incompatible race of Phytophthora infestans. Among these enzyme inhibitors, NaN3 and 2, 4-DNP have been supposed to inhibit the hypersensitive cell deaht by reducing ATP levels. In the present experiments, ATP contents in the potato tuber disks treated with these inhibitors were determined by using the luciferin-luciferase methods. Thin disks 0.5 mm thick, which consist of 2.3 cell layers in average, were used, so that almost all of the total cells were exposed to the inhibitors. Therefore, the analytical results were thought to indicate ATP levels in the cells exposed directly to the inhibitors. Experiments showed that 2, 4-DNP and NaN3 reduced ATP level and also inhibited hypersensitive cell death upon infection when aged disks were treated. When the fresh disks were treated with 2, 4-DNP or NaN3 and then ATP contents were determined 20 hr after the treatment, ATP levels remained low only in the former case, while in the latter almost the same level as the water-treated disks was regained. At one day after treatment of the fresh disks with 2, 4-DNP or NaN3, the potential of hypersensitive reactivity (hypersensitive cell death) was low in the former and high in the lattter. PCMB and PMDT did not reduce the ATP level but inhibited the hypersensitive cell death. BcS also failed to reduce the ATP level. These results were consistent with the presumption that BcS inhibits the development of the potential to react hypersensitively to the incompatible race, that PCMB and PMDT inhibit the hypersensitive cell death through a mechanism other than the inhibition of ATP generation, possibly by affecting the cell membrane, and that NaN3 and 2, 4-DNP may inhibit the hypersensitive cell death by inhibiting ATP generation.
    Download PDF (390K)
  • Takahito NODA, Teruyoshi HASHIBA, Zenji SATO
    1980 Volume 46 Issue 1 Pages 40-45
    Published: January 25, 1980
    Released: February 19, 2009
    JOURNALS FREE ACCESS
    The number and width of exodermal and cortical cells in swollen rice seedling roots infected with Rhizopus chinensis or induced by the toxin produced by the pathogen increased and the thickness of the cortical cell walls also increased to about 3 times compared with those of healthy roots. Hyphal penetration into the inner layers was not observed.
    Download PDF (3623K)
  • Takahito SUZUI, Tokio MAKINO
    1980 Volume 46 Issue 1 Pages 46-48
    Published: January 25, 1980
    Released: February 19, 2009
    JOURNALS FREE ACCESS
    Download PDF (1679K)
  • Tadao INOUYE, Takeshi OSAKI
    1980 Volume 46 Issue 1 Pages 49-50
    Published: January 25, 1980
    Released: February 19, 2009
    JOURNALS FREE ACCESS
    Yellow vein of Eupatorium chinense var. simplicifolium caused by a geminivirus (Osaki and Inouye, 1979) had long been attracted attentions by some Japanese botanists and plant pathologists. A poem written by the Empress Koken on the yellow leaf of Eupatorium in the year of 752 that appeared in “Manyoshu” would be the first record in all over the world in the literature of the possible plant virus disease.
    Download PDF (1097K)
  • Satoshi T. OHKI, Kenichiro SHOHARA, Tadao INOUYE
    1980 Volume 46 Issue 1 Pages 51-53
    Published: January 25, 1980
    Released: February 19, 2009
    JOURNALS FREE ACCESS
    Download PDF (1106K)
  • Seiko IMAIZUMI, Susumu KUBO
    1980 Volume 46 Issue 1 Pages 54-56
    Published: January 25, 1980
    Released: February 19, 2009
    JOURNALS FREE ACCESS
    Location of tobacco necrotic dwarf virus antigen in plant tissues was detected by the fluorescent antibody staining method.
    The antigen was restricted to phloem tissue in tobacco, Physalis floridana and spinach. A method using polyethylene glycol 1000 for embedding tissues fixed with the Carnoy's fixative was proved to be rapid and effective to detect the specific fluorescence in tissue sections.
    Download PDF (854K)
  • 1980 Volume 46 Issue 1 Pages 57-65
    Published: January 25, 1980
    Released: February 19, 2009
    JOURNALS FREE ACCESS
    Download PDF (887K)
  • 1980 Volume 46 Issue 1 Pages 65-71
    Published: January 25, 1980
    Released: February 19, 2009
    JOURNALS FREE ACCESS
    Download PDF (696K)
  • 1980 Volume 46 Issue 1 Pages 72-78
    Published: January 25, 1980
    Released: February 19, 2009
    JOURNALS FREE ACCESS
    Download PDF (706K)
  • 1980 Volume 46 Issue 1 Pages 79-88
    Published: January 25, 1980
    Released: February 19, 2009
    JOURNALS FREE ACCESS
    Download PDF (1034K)
  • 1980 Volume 46 Issue 1 Pages 88-99
    Published: January 25, 1980
    Released: February 19, 2009
    JOURNALS FREE ACCESS
    Download PDF (1208K)
  • 1980 Volume 46 Issue 1 Pages 99-112
    Published: January 25, 1980
    Released: February 19, 2009
    JOURNALS FREE ACCESS
    Download PDF (1385K)
feedback
Top