Japanese Journal of Phytopathology
Online ISSN : 1882-0484
Print ISSN : 0031-9473
ISSN-L : 0031-9473
Volume 54 , Issue 2
Showing 1-20 articles out of 20 articles from the selected issue
  • Ryozo YOKOSAWA, Haruo SEKIZAKI, Shiro KUNINAGA
    1988 Volume 54 Issue 2 Pages 133-140
    Published: April 25, 1988
    Released: February 19, 2009
    JOURNALS FREE ACCESS
    Zoospores of Aphanomyces cochlioides were attracted to hypocotyls of sugar beet seedlings and formed localized masses of encysted zoospores. From these sites of encystment, the zoospores invaded the plants. Sodium nitrate, potassium nitrate and sodium chloride were isolated from sugar beet seedlings as the attractant. The concentrations required for attraction ranged from 10-3 to 10-2 M. Tests using commercially available compounds indicated attraction could be attributed to nitrate (NO3-) and chloride (Cl-) ions. The concentrations of these ions in hypocotyls were six and four times as high, respectively, as those in roots. The concentrations of these ions in exudates from hypocotyls and roots were almost the same. It is suggested that zoospores are attracted to hypocotyls by these ions and massed zoospores play a major role in the occurrence of damping off of sugar beet seedlings by A. cochlioides.
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  • Wan Gyu KIM, Reiichi YOSHINO
    1988 Volume 54 Issue 2 Pages 141-150
    Published: April 25, 1988
    Released: February 19, 2009
    JOURNALS FREE ACCESS
    Twelve isolates of Rhizoctonia solani AG-1(IA) from each different location of Korea, four isolates of R. solani AG-1(IA) and three isolates of R. solani AG-2-2(IIIB) from several locations of Japan having different cultural ages were tested for the reaction and frequency of hyphal anastomosis by WA-cellophane culture. All the isolates except one made cytoplasmic (perfect) fusions without cell death or killing reaction and contact fusions in their self-anastomosis. One AG-2-2(IIIB) isolate made only contact fusions in its self-anastomosis, although it made non-cytoplasmic (imperfect) fusions and contact fusions at low frequency with two different AG-2-2(IIIB) isolates. Of the AG-1(IA) isolates, only the isolate WJB-5 from Korea made cytoplasmic fusions at 57.3% and 54.3% with the isolate 57-6 and HR-1 from Japan, respectively, and the others from Korea made non-cytoplasmic fusions at 47.3-68.0% and contact fusions at 0.7-18.0% with those from Japan. Five AG-1(IA) isolates from Korea including WJB-5 did not make cytoplasmic fusions each other, although non-cytoplasmic fusions and contact fusions occurred among them. The cytoplasmic fusion also did not occur in five pairings of the AG-1(IA) isolates from Japan except the pairing of 57-6 and HR-1. However, the cytoplasmic fusions which occurred between 57-6 and HR-1 occasionally showed abnormal forms of the fused cells, and their frequency was usually lower than that between WJB-5 and 57-6, or WJB-5 and HR-1. Cytoplasmic fusion did not occur in any pairing of three CFIs (cytoplasmic fusion isolates) and ten AG-1(IA) isolates from the same geographic origins of two CFIs, but non-cytoplasmic fusion and contact fusion occurred. The incident property and frequency of cytoplasmic fusion among the CFIs were not varied by subculturing the isolates on PDA. The results revealed that the characteristics in hyphal anastomosis of R. solani AG-1(IA) were not related to the locality and cultural ages of the isolates.
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  • Yoshikatsu FUJITA, Hozumi SUZUKI
    1988 Volume 54 Issue 2 Pages 151-157
    Published: April 25, 1988
    Released: February 19, 2009
    JOURNALS FREE ACCESS
    The resistance in soybean (Glycine max) and wild soybean (G. sofa) to purple seed stain (Cercospora kikuchii) was studied by using three soybean cultivars (Oshimashirome, Raiden, Hanayome) and one wild soybean line (E-1). Four phases in the infection process, rate of spore germination, elongation of germ tubes, formation of infection structure, and penetration, did not differ among the soybean cultivars. For both resistant soybean cultivar (Hanayome) and wild soybean, the growth of hyphae in pods was not stopped, but slow in speed. In this respect, the resistance in pods of soybean and wild soybean seemed to be derived from the same mechanism. The resistance that actually prevented the hyphal penetration into seeds was caused by hard-coatedness and this was identified only in the wild soybean. On the other hand, the resistance of seed itself was not observed in all the soybean cultivars tested because the fungus, when inoculated directly to seeds, could penetrate the seeds of all the cultivars almost equally. The results indicate that the apparent resistance of seeds of a soybean cultivar, e.g. Hanayome, grown under field conditions is not due to the resistance of seed but to the resistance of pod tissue.
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  • Tsai-young CHUANG, Wen-hsiung Ko
    1988 Volume 54 Issue 2 Pages 158-163
    Published: April 25, 1988
    Released: February 19, 2009
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    Chlamydospores of Rhizoctonia solani pre-suspended in 20% V-8 broth for 10 min were added to the surface of soil blocks to measure suppressiveness of soils based on their ability to support spore germination. About 15% of the 124 soil samples collected from various locations on the island of Hawaii were suppressive to R. solani supporting less than 50% germination of chlamydospores. There was a direct relationship between percentage of chlamydospore germination and soil pH. Without repeated plantings of radish, there was no difference in propagule number of R. solani in suppressive and conducive soils. However, at the end of the third weekly plantings of radish, the propagule number of R. solani decreased in suppressive soil but not in conducive soil. In comparison with hyphal-growth assay, the germination test is relatively fast and precise for measuring suppressiveness of soils to R. solani. It also requires less soil for each replicate.
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  • Hideki TAKAHASHI, Yoshio EHARA
    1988 Volume 54 Issue 2 Pages 164-173
    Published: April 25, 1988
    Released: February 19, 2009
    JOURNALS FREE ACCESS
    Infection of tobacco (Nicotiana tabacum L. cv. Ky57) leaves with the yellow strain of cucumber mosaic virus (CMV(Y)) resulted in large chlorotic spot formation, while no clear symptom appeared with the ordinary strain of the virus (CMV(O)) except for faint yellowing. In spite of the marked difference in symptom appearance on the tobacco between the two virus strains, the time course and extent of the virus titer and coat protein synthesis were essentially similar for both strains. In the leaves inoculated with CMV(O), 80 s ribosome concentration and host protein synthesis decreased temporarily, and then they were recovered moderately when the virus titer reached a maximum. 70 s ribosome concentration decreased to a small extent, and poly(A)-mRNA synthesis and polysome concentration were little affected throughout the experimental periods. In the leaves infected with CMV(Y), in comparison with CMV(O), poly(A)-mRNA synthesis and polysome concentration first decreased almost simultaneously, and followed by the decrease of host protein synthesis, and then 80 s and 70 s ribosome concentrations decreased significantly in the order. Thus, it is suggested that a series of such reactions lies at the basis of symptom appearance. Incidentally, no increase in activities of protease and ribonuclease was observed in the leaves inoculated with the two virus strains.
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  • Piara S. BAINS, Hanumantha R. PAPPU, Chuji HIRUKI
    1988 Volume 54 Issue 2 Pages 174-182
    Published: April 25, 1988
    Released: February 19, 2009
    JOURNALS FREE ACCESS
    Isolation of pea (Pisum sativum L. cv. Alaska) mesophyll protoplasts by both the ‘one-step’ and the‘modified two-step’ methods resulted in similar yields (1-1.5×107 protoplasts per g fresh weight of leaves). The time of protoplast isolation was considerably reduced, from 2 hr to 35 min. by including Pectolyase Y23 in the digestion medium. Maximum infection, 57%, was obtained at concentrations of 1.0 to 1.4μg/ml for poly-L-ornithine and 3μg/ml for clover yellow mosaic virus (CYMV), using 0.24 M phosphate (K2HPO4-KH2PO4) buffer pH 6.3 as inoculation buffer. The replication of CYMV-RNA in protoplasts was followed by Northern blotting using specific cDNA probe. Synthesis of genomic RNA was detected from 12 hr after inoculation. Polyethylene glycol-mediated inoculation with CYMV-RNA resulted in about 35% infection of viable protoplasts.
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  • Nobuaki MATSUYAMA, Satoshi WAKIMOTO
    1988 Volume 54 Issue 2 Pages 183-188
    Published: April 25, 1988
    Released: February 19, 2009
    JOURNALS FREE ACCESS
    Some diterpenoid anti-blast substances which were found in blast-infected rice leaves and detectable by GLC (OV-17) were isolated and purified by using LC, preparative HPLC and TLCs. These substances were analyzed by GC-MS, MS and HR-MS. The substance 17-3M was identified as S-1 (C20H32O2, Mole. Wt. 304) which was previously reported. The substance 14-6M was analyzed as C20H30O2, Mole. Wt. 302. The molecular weight of the substance 14-7M was 302 and it was assumed as C20H30O2. The substance 12-7M was also detectable by GLC at similar retention time with other substances and distinctly different from Oryzalexins which were formerly reported. The analyses of the fractions from HPLC indicated the existence of several derivatives which could be novel substances.
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  • Masao GOTO, Ben Li HUANG, Takahiro MAKINO, Takao GOTO, Tadaoki INABA
    1988 Volume 54 Issue 2 Pages 189-197
    Published: April 25, 1988
    Released: February 19, 2009
    JOURNALS FREE ACCESS
    The ice nucleation-active bacteria (INAB) isolated from gemmisphere of tea plants belonged to three genera; Erwinia (23 strains), Xanthomonas (44 strains), and Pseudomonas (1 strain). The strains of Erwinia isolated from tea fields in Shizuoka prefecture in 1978-1980, and in Kagawa pref. in 1987 were identified as E. ananas. An ice nucleation-active xanthomonad detected with a high frequency in Shizuoka pref. and Tokushima pref. in 1986-1987 was, however, identified as a strain of X. campestris from morphological, physiological, and biochemical traits. The bacterium was also found on some vegetables in Shizuoka pref. with a low frequency, but it was not pathogenic to any carrier plants from which it was isolated. The taxonomic affiliation of this bacterium was left for future study, although the new subspecific rank was suggested to be more eligible than the pathovar rank. The strains of INAB isolated from flowers of Magnolia denudata and leaves of various vegetables in Shizuoka pref. and a strain isolated from tea gemmisphere in Kagawa pref. were identified as P. syringae. Although they were identical either with P. syringae pv. delphinium (17 strains) or P. syringae pv. syringae (1 strain) in biochemical tests, all strains were not pathogenic to any carrier plants and Delphinium spp. as well. However, all of six strains that were arbitrarily selected, formed water-soaked lesions on the leaves of lilac (Syringa vulgaris L.) through stomata and wounds. Therefore, these strains were identified as P. syringae pv. syringae. A strain of INAB isolated from Wasabi petiole was a non-fluorescent pseudomonad with positive tobacco HR. Although the diagnostic traits of the bacterium were similar to those of P. cichorii, it showed no pathogenicity to any plants tested including Wasabi and lettuce. Therefore, its taxonomic affiliation was left for future study. All INAB mentioned above showed the type A ice nucleation-activity, i.e. the supercooling temperature was between -2.8 and -3 C except for the Wasabi pseudomonad at -4 and -5 C.
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  • Norio KONDO, Fujio KODAMA, Masaharu OZAKI, Jun AKAI
    1988 Volume 54 Issue 2 Pages 198-203
    Published: April 25, 1988
    Released: February 19, 2009
    JOURNALS FREE ACCESS
    It was shown by inoculations that ascospores of Sclerotinia sclerotiorum invaded the sunflower head mainly through florets with a period of 10 to 24 days from infection until the first visual symptoms appear under summer condition. In the field, numerous apothecia were found on the ground during late July to early August. No apothecia were detected in September. The occurrence of head rot closely correlated with number of apothecia appearing in the field at the flowering time of sunflower; frequency of head rot was higher when a lot of apothecia were observed at the flowering time of sunflower (40 apothecia/m2, 27% plants affected with head rot at Naganuma field), while it was only slight when few apothecia were observed (2 apothecia/m2, 2% plants affected with head rot). The difference of the flowering time accounted for the difference of disease incidence among 11 sunflower cultivars tested; the significantly different disease incidences were observed between early flowering group and late flowering group. The head rot was effectively controlled by spraying the fungicide vinclozolin (500 ppm a.i.) five times at 2 to 3 days intervals during late anthesis stage. The amount of sprays was 250 liters/1, 000m2.
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  • Takeshi OSAKI, Tadao INOUYE
    1988 Volume 54 Issue 2 Pages 204-209
    Published: April 25, 1988
    Released: February 19, 2009
    JOURNALS FREE ACCESS
    Pea stem necrosis virus (PSNV) particles were isometric and 34 run in diameter, and showed rounded outlines with rough surfaces when they were examined in electron microscope after negative-staining using uranyl acetate. In ultrathin sections, large numbers of virus particles were consistently scattered within the ground cytoplasm in cells of most tissues of infected pea leaves. Crystalline arrays of virus particles were observed only in necrotic cells. No virus particles were detected in nuclei, chloroplasts or mitochondria. A characteristic feature in infected cells was the formation of small vesicles, bounded by a single membrane, at the peripheries of the mitochondria which are superficially quite similar to multivesicular bodies induced by some other plant viruses. Possible affinities of PSNV with the tombusvirus group are discussed and it is suggested that PSNV may be grouped with certain other single-component viruses such as carnation mottle or galinsoga mosaic viruses.
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  • Takeshi OSAKI, Kenji OZAKI, Tadao INOUYE
    1988 Volume 54 Issue 2 Pages 210-216
    Published: April 25, 1988
    Released: February 19, 2009
    JOURNALS FREE ACCESS
    Pea stem necrosis virus (PSNV) was readily purified from infected pea plants by a chloroformbutanol procedure with yields of about 200mg/kg leaf tissues. Purified virus preparations contained a single sedimenting component with a sedimentation coefficient of 118S, buoyant density in cesium chloride of 1.35g/cm3 and nucleic acid content of 17%. Polyacrylamide gel electrophoresis demonstrated single nucleic acid component and single coat protein with estimated molecular weights of 1.53×106 and 38, 000 daltons, respectively. Nucleic acid extracted from the virus preparations was identified as single-stranded RNA by the following properties: positive orcinol reaction; susceptibility to RNase A both in 1×SSC or 0.1×SSC; increase of about 21% in maximum absorption and shift both the absorption maximum and minimum to higher wave-lengths by 4 nm on treatment with formaldehyde (1.8%). Preparations of purified particles of PSNV reacted with homologous antiserum (gel diffusion titer, 1:1, 024) but not with any antisera to 8 different plant viruses with isometric particles including tomato bushy stunt, galinsoga mosaic, carnation mottle or melon necrotic spot viruses. However, physicochemical properties were similar to those of carnation mottle and allied viruses.
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  • Yoshiyuki TAKAHASHI, Toshihiro OMURA, Takaharu HAYASHI, Kenichiro SHOH ...
    1988 Volume 54 Issue 2 Pages 217-219
    Published: April 25, 1988
    Released: February 19, 2009
    JOURNALS FREE ACCESS
  • Shosuke KATO, Toshiki SHIOMI, Hidehiko WAKIBE, Setsuo IWANAMI
    1988 Volume 54 Issue 2 Pages 220-223
    Published: April 25, 1988
    Released: February 19, 2009
    JOURNALS FREE ACCESS
    A disease of tomato, showing the symptoms of yellows and stunting, was found in Saga and Hiroshima Prefectures in 1983 and 1984, respectively. Electron microscopy revealed the presence of numerous mycoplasmalike organisms (MLOs) in the phloem tissues of the diseased plants. Of the two leafhoppers tested, Macrosteles orientalis Virbaste and Scleroracus fiavopictus Ishihara, only M. orientalis transmitted the disease. Tomato yellows MLO described in this work had a wide host range similar to that of onion yellows MLO.
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  • Yuichi TAKIKAWA, Yasuo ANDO, Etuji HAMAYA, Shinji TSUYUMU, Masao GOTO
    1988 Volume 54 Issue 2 Pages 224-228
    Published: April 25, 1988
    Released: February 19, 2009
    JOURNALS FREE ACCESS
    A bacterial disease of tea plant was observed in Shizuoka Prefecture in July, 1983. The symptoms were characterized by leaf spots with irregular shape and apparent necrosis of the spongy parenchyma tissue. Two distinct pseudomonads were isolated from these lesions. On the basis of bacteriological and pathological tests, they were identified as Pseudomonas syringae pv. theae and P. avenae, respectively. P. syringae pv. theae was isolated with high frequency, and produced the typical shoot blight symptoms or the characteristic leaf spot symptoms depending upon the temperature and humidity in inoculation tests and the variety of tea plants. P. avenae was isolated with lower frequency, and produced leaf spot symptoms different from those observed in the field in color and shape. From these results, the present disease was determined as one of the symptoms of bacterial shoot blight caused by P. syringae pv. theae. The role of P. avenae in this hacteriosis remained to be clarified.
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  • Hironori KOGA, Reiichi YOSHINO
    1988 Volume 54 Issue 2 Pages 229-232
    Published: April 25, 1988
    Released: February 19, 2009
    JOURNALS FREE ACCESS
    Rice panicles spontaneously infected with Pyricularia oryzae Cav. were stained with calcofluor white to impart fluorescence to fungal structures. The procedure facilitated observation of conidiophores and conidia formed on infected sites such as neck, rachis, panicle branch, pedicel and husk, and of invading hyphae in the cells of neck, rachis and panicle branch. It is also possible to observe conidia attached to the epidermis of neck, rachis, panicle branch, pedicel and husk.
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  • Masato IKEGAMI, Tsutou MORINAGA, Kin-ichiro MIURA
    1988 Volume 54 Issue 2 Pages 233-237
    Published: April 25, 1988
    Released: February 19, 2009
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  • Niphon VISARATHANONTH, Makoto KAKISHIMA, Yukio HARADA
    1988 Volume 54 Issue 2 Pages 238-241
    Published: April 25, 1988
    Released: February 19, 2009
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  • Tsutomu ARIE, Shigetou NAMBA, Shuichi YAMASHITA, Yoji DOI
    1988 Volume 54 Issue 2 Pages 242-245
    Published: April 25, 1988
    Released: February 19, 2009
    JOURNALS FREE ACCESS
    Indirect fluorescent-antibody technique was applied for diagnosis of the clubroot of Brassicaceae caused by Plasmodiophora brassicae Woron. IgG (γ-globulin; 0.91 mg/ml) was purified from antiserum against resting spores of P. brassicae prepared from a rabbit. Infested soil and root were stained by fluorescent-antibody technique with the IgG and FITC conjugated antirabbit IgG-sheep IgG. (Cappel Lab.) Resting spores were effectively detected, and also clearly differentiated from small particles of soil and tissues of plant in the reflected light fluorescence microscope (Olympus BHS-RF-A, B-excitation). This method is considered to be suitable for the detection of P. brassicae.
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  • Nobuyuki OSHIMA, Kenichiro SHOHARA, Yoshiyuki TAKAHASHI, Takao ARAKI
    1988 Volume 54 Issue 2 Pages 246-249
    Published: April 25, 1988
    Released: February 19, 2009
    JOURNALS FREE ACCESS
    Watering of 200ml 0.025-1% benomyl (50% WP) suspension per plant to the basement soil of potted Samsun tobacco plants caused very considerable reduction of the severity of TMV-L (a tomato strain of TMV) symptoms. ELISA absorbance showed that in two weeks after inoculation TMV-L concentration of upper leaves of tobacco plants treated with 200ml 0.1% benomyl suspension was a quarter of that of control plants. In one month after inoculation, however, there was no difference between those concentrations. Watering of 200ml 0.1-0.5% benomyl solution per plant to Xanthi-nc tobacco plants caused a slight reduction of the severity of PVY-T (a necrotic strain of PVY) symptoms. Combined application of benomyl and 2, 4-dioxohexa-hydro-1, 3.5-triazine (2% granules) showed no obvious effects of combination against the symptoms by TMV-L or PVY-T.
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  • Noriki HAYASHI, Takashi TSUGE, Hirokazu KOBAYASHI, Syoyo NISHIMURA
    1988 Volume 54 Issue 2 Pages 250-252
    Published: April 25, 1988
    Released: February 19, 2009
    JOURNALS FREE ACCESS
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