Japanese Journal of Phytopathology
Online ISSN : 1882-0484
Print ISSN : 0031-9473
ISSN-L : 0031-9473
Volume 60 , Issue 5
Showing 1-16 articles out of 16 articles from the selected issue
  • Tomio USUGI, Masaaki NAKANO, Masatoshi ONUKI, Tetsuo MAOKA, Takaharu H ...
    1994 Volume 60 Issue 5 Pages 545-554
    Published: October 25, 1994
    Released: February 19, 2009
    JOURNALS FREE ACCESS
    A new filamentous virus (designated VC) was isolated from sweet potato plants that seemed to be tolerant to russet crack. It infected Ipomoea spp., Chenopodium quinoa and C. amaranticolor. Ipomoea nil infected with the virus developed typical vein-clearing on the first true leaf. The infectivity of VC in sap was lost at dilutions between 1:10, 000 and 1:100, 000 and after storage for one day at 20°C. Its thermal inactivation point was between 50 and 60°, and virus particles were 850-880nm long and 13nm wide. VC was nonpersistently transmitted by the aphid Myzus persicae, and was serologically related but not identical to sweet potato feathery mottle virus (SPFMV, abbreviated as Mo) that belongs to Potyvirus. Coat proteins of both purified VC and Mo migrated as three major bands of proteins with Mr 32, 000, 30, 000 and 29, 000. However, electro-blot immunoassay revealed one major protein of Mr 38, 000 and an additional, more slowly migrating protein of Mr 97, 000 in leaves infected with VC, and one major protein of Mr 38, 000 in leaves infected with Mo. Sweet potato inoculated with VC developed symptoms of russet crack on the fleshy roots. These results indicate that VC is the causative agent of russet crack that occurs in some Japanese cultivars of sweet potato and that VC is a new strain of SPFMV. Therefore, we named VC and Mo severe strain (SPFMV-S) and ordinary strain (SPFMV-O), respectively, of SPFMV.
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  • Shigemitsu TORIYAMA, Yoshihiko SUZUKI, Yuji GOTO, Makoto KOJIMA
    1994 Volume 60 Issue 5 Pages 555-562
    Published: October 25, 1994
    Released: February 19, 2009
    JOURNALS FREE ACCESS
    The RNA Polymerase associated with filamentous nucleoproteins of rice stripe virus (RSV) was irreversibly inactivated, when incubated in high concentrations of salts such as NaCl, KCl, CsCl, and NH4Cl. In contrast, (NH4)2SO4, Na2SO4, and Cs2SO4 did not affect the polymerase activity. In the standard assay mixture in which salts were incorporated, the SO42- salts were more inhibitory to RNA polymerase activity than the Cl- salts. With increasing concentrations of these salts, the fine, partially unfolded filamentous particles of RSV became more tightly coiled into stiff and rigid rods or apparently supercoiled circular filamentous particles. No distinct difference in structures of folded RSV particles was observed between Cl- and SO42- salts. The circular dichroism (CD) spectrum of RSV preparations in either the presence or absence of salts was that of a typical α helix. These observations indicate the tight folding of RSV particles in response to salts could be caused by tight stacking of the protein subunits in filamentous particles of RSV. The inhibitory effect of salts on the RNA polymerase activity is discussed.
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  • Yuichi YAMAOKA, Hajime IIDA, Makoto KAKISHIMA
    1994 Volume 60 Issue 5 Pages 563-568
    Published: October 25, 1994
    Released: February 19, 2009
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    Since summer in 1991, a new rust disease has occurred on leaves of potted plants of Kalanchoe blossfeldiana growing in greenhouses in Konosu, Saitama Prefecture. Dark brown pustules in lesions on the leaves were mainly composed of 2-celled teliospores, with a few 1-celled ones. Leaves of potted plants of K. blossfeldiana were artificially inoculated with basidiospores. Whitish spots appeared on the upper surface of the leaves eight to nine days after inoculation. Sixteen to 19 days after inoculation, dark brown pustules containing teliospores appeared in the lesions. The fungus was also able to infect Sedum kamtschaticum and Sedum sp. From morphological observation of the teliospores and from results of inoculation experiments, the causal fungus of the disease was identified as Puccinia benkei Kusano, a microcyclic rust. We propose ‘Sabi-byo’ and ‘Rust’ as a Japanese common name and an English common name of the new disease on Kalanchoe, respectively.
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  • Nobuyuki YOSHIKAWA, Hitoshi NAKAMURA, Norio SAHASHI, Takanori KUBONO, ...
    1994 Volume 60 Issue 5 Pages 569-575
    Published: October 25, 1994
    Released: February 19, 2009
    JOURNALS FREE ACCESS
    To establish a sensitive and reliable detection method of paulownia witches' broom (PWB)-MLO, polymerase chain reactions (PCR) using two primer pairs for ribosomal protein (rp) and 16S rDNA (rD) were conducted. DNA fragments, 1.2kbp for the rp primer pair and 1.3kbp for the rD primer pair, were amplified in DNA samples extracted from infected paulownia leaves but not in healthy leaves, in controlled PCR conditions. Based on the use of both primer pairs, these disease-specific DNAs were detected after amplification of 100pg of total DNA from infected leaves. The nucleotide sequences of amplified ribosomal protein and 16S rRNA genes show that PWB-MLO is closely related to aster yellows type-MLOs.
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  • Seiya TSUSHIMA, Chitoshi NARIMATSU, Akifumi MIZUNO, Ryosuke KIMURA
    1994 Volume 60 Issue 5 Pages 576-584
    Published: October 25, 1994
    Released: February 19, 2009
    JOURNALS FREE ACCESS
    A 5.7-kilobase EcoRI fragment, PG2I, and a 3.9-kilobase EcoRI fragment, PG80I, were cloned randomly from the total DNA of Pseudomonas glumae, the causal agent of bacterial grain rot of rice. PG2I hybridized to all the 43 strains of P. glumae isolated from rice grain, rice seedlings, rice leaf sheaths and mung bean sprouts from different places, but PG80I did not hybridize to 5 of the 43 strains. PG2I seemed specific to this pathogen because this fragment failed to hybridize to selected strains of gram negative bacteria including P. gladioli pv. gladioli, P. gladioli pv. allicola, P. caryohylli, P. plantarii, P. solanacearum, P. cepacia, P. avenae, P. cichorii, P. aeruginosa, P. syringae pv. phaseolicola, P. syringae pv. syringae, P. viridiflava, P. marginalis pv. marginalis, Agrobacterium radiobacter, A. rhizogenes, A. tumefaciens, Erwinia ananas, E. carotovora subsp. carotovora, E. herbicola, X. campestris pv. campestris, and X. campestris pv. oryzae, and gram positive bacteria including Arthrobacter illicis, Clavibacter michiganensis subsp. michiganensis, Cl. michiganensis subsp. sepedonicus, Cl. rathayi, Curtobacterium albidum, C. citreum, C. flaccumfaciens pv. flaccumfaciens, C. flaccumfaciens pv. oortii and Rhodococcus fasciens. When PG2I was separated into two fragments, PG2Ia and PG2Ib, by digestion with KpnI, PG2Ia hybridized to all the strains but PG2Ib did not hybridize to 18 of the 43 strains of P. glumae, indicating that PG2Ia is specific to this pathogen. Hybridization patterns of PG2Ib and PG80I to these strains showed that they were divided into 4 groups and that at least three groups were present in three localities in Oita Prefecture in 1984. These findings suggest allopatric differentiation of different strains of P. glumae. These probes are considered to be useful for the detection of P. glumae in ecologial studies.
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  • Shinzo KOIZUMI
    1994 Volume 60 Issue 5 Pages 585-594
    Published: October 25, 1994
    Released: February 19, 2009
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    Effect of field resistance on the development of leaf blast in mixtures of susceptible and resistant rice cultivars was studied in three field experiments (one in the upland nursery and two in the paddy fields) by using two susceptible rice cultivars with different (low and intermediate) levels of field resistance to the disease. In the upland nursery experiment where infected leaves with blast fungus were strewed uniformly in the plots and in the paddy experiment in 1982 where the disease occurred naturally, the disease severity on respective susceptible cultivars decreased with the reduction in the proportion of the susceptible cultivars in the plots, and the decrease for the cultivar with a low level of field resistance (LFC) was greater than that for the cultivar with an intermediate level of the resistance (MFC). Similar results were obtained in the paddy experiment in 1981 where an inoculum source was placed at the center of each plot. Since leaf blast severity in each experiment was smaller for MFC than for LFC and the disease gradient on the susceptible cultivar from the inoculum source was steeper for MFC than for LFC in the paddy experiment in 1981, it was assumed that less spread of the disease between plants on MFC reduced the effectiveness of the mixtures for the control of the disease.
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  • Toru IWANAMI, Hiroyuki IEKI
    1994 Volume 60 Issue 5 Pages 595-599
    Published: October 25, 1994
    Released: February 19, 2009
    JOURNALS FREE ACCESS
    Ribavirin was applied as a foliar spray to the growing shoots of potted citrus plants of several cultivars infected with various sources of citrus tatter leaf virus (CTLV). The buds on the treated shoots were grafted on rough lemon rootstocks top-worked with rusk citrange for indexing immediately after the applications. Six or eight weekly applications of 500ppm ribavirin eliminated all but one source (Kanp-90 in Ponkan mandarin) of CTLV from the buds with high efficiency. Kanp-90 could be eliminated from Ponkan mandarin by application of 500ppm ribavirin in combination with heat treatment. Application of 50ppm of ribavirin did not eliminate any source of CTLV.
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  • Kazusato OHSHIMA, Akihiro MATSUURA, Takaaki NAKAYA, Eishiro SHIKATA, K ...
    1994 Volume 60 Issue 5 Pages 600-607
    Published: October 25, 1994
    Released: April 03, 2009
    JOURNALS FREE ACCESS
    cDNA to a plant virus-monoclonal antibody gene was cloned and sequenced. The source of mRNAs was a hybridoma producing an IgG3 monoclonal antibody (42C07) which bound to a coat protein of potato virus Y. We have constructed cDNA libraries using a bacteriophage lambda ZAP II vector from the mRNA of the hybridomas. Screening of the libraries with polymerase chain reaction-mediated probes specific to variable and a part of constant regions of the heavy and light chain genes yielded clones of both chains. Numbers of the nucleotides encoding heavy and light chains were 1383 and 717, and numbers of the deduced amino acids were 461 and 239, respectively. Comparisons of the deduced amino acid sequences with those of other immunoglobulin (Ig) previously reported showed that they were full-length of the antibody gene. Furthermore, the heavy and light chains of 42C07 were successfully expressed separately in Escherichia coli as judged by reactivities with anti-mouse Ig antibody.
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  • Hideo NASU, Akira NAKAGIRI, Tadayoshi ITO, Motomu HATAMOTO
    1994 Volume 60 Issue 5 Pages 608-612
    Published: October 25, 1994
    Released: February 19, 2009
    JOURNALS FREE ACCESS
    In the autumn of 1976 and 1993, an unknown disease of grape, caused by Briosia ampelophaga Cav., was found in Okayama Prefecture, Japan. This report describes the new disease of grape, the causal fungus and inoculation experiments in Japan.
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  • Jin YAN, Ichiro UYEDA, Ikuo KIMURA, Eishiro SHIKATA, Chung-Chung CHEN, ...
    1994 Volume 60 Issue 5 Pages 613-616
    Published: October 25, 1994
    Released: February 19, 2009
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  • Ken'o OKAYAMA, Akira TSUJIMOTO
    1994 Volume 60 Issue 5 Pages 617-623
    Published: October 25, 1994
    Released: February 19, 2009
    JOURNALS FREE ACCESS
    A new strawberry anthracnose caused by Glomerella cingulata was found in September, 1987. Small dark lesions appeared on leaflets, runners and petioles of the plants in the nursery, and infected plants often wilted suddenly and died. A reddish-brown streaking occurred in interior portions of crowns of wilted plants, and the fungus was isolated from these lesions. Although the pathogen of strawberry anthracnose was reported as Colletotrichum fragariae in Japan in 1969, C. fragariae had been considered to be the synonym of C. gloeosporioides by von Arx. Symptoms and morphological characteristics of conidia isolated in this study were similar to those of C. fragariae. Perithecia were formed on the surface of crowns and runners as well as on the culture medium. Ascomata were dark brown, spherical, and discrete or aggregated. Asci contained 8 aseptate, hyaline and curved ascospores. On the basis of these morphological characteristics, the causal fungus was identified as Glomerella cingulata (Stoneman) Spaulding et Schrenk (Colletotrichum gloeosporioides Penzig). The fungus also was pathogenic on foliage of broad bean, pea and cyclamen, and on fruits of apple and avocado, but nonpathogenic to Solanaceae, Cucurbitaceae and some woody plants.
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  • Yukio HARADA, Masahito MITSUHASHI, Masaki MATSUDA
    1994 Volume 60 Issue 5 Pages 624-629
    Published: October 25, 1994
    Released: February 19, 2009
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    In Japan, kernel bunt of rice, caused by the fungus Neovossia horrida (Tak.) Padw. & Khan, is usually of minor importance with negligible losses. Occassionally, however, an unusual outbreak of the disease has been noticed locally, where almost all spikes were affected showing very high incidence of the diseased grains on them. Such a sporadic, unusual occurrence of the disease enabled us to assume that some unknown infection mechanism, other than floral infection during anthesis, might operate for the development of the disease. In 1989 and 1990, a series of boot inoculations were made of rice plants (Oryza sativa L.) to see whether or not the spikes in boot stage or just in heading were liable to infection with the fungus. Two ml each of inoculum (culture filtrates of the fungus which contained 2×105 conidia (secondary sporidia)/ml) were injected with a hypodermic syringe into a boot (sheath) at different growth stages (from panicle-formation stage to heading time). The rice plants were grown in pots and kept in a glasshouse throughout the experiments. Inoculations during the period of late boot stage (2 days before heading) to heading time resulted in high rates of infection (9 spikes out of 20 inoculated in 1989 and all 9 spikes inoculated in 1990). Percent diseased grains on each infected spikes were 27.8-60.0 (av. 40.8) and 4.4-55.1 (av. 25.2) respectively in 1989 and 1990. Diseased grains of various symptom types were produced, among which grains showing no apparent fungus structure outside but filled inside with teliospore masses were most numerous (36.3% and 63.2% respectively in 1989 and 1990). On the other hand, inoculations at or before early boot stage (6 days before heading time) were all unsuccessful. None of the uninoculated control plants was infected. The success of boot inoculations would make a proof of the previously reported effectiveness of chemicals sprayed on rice plants at boot stage in controlling the disease.
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  • Hozumi YOSHIDA, Takeshi YAMADA, Naoharu MIZUNO
    1994 Volume 60 Issue 5 Pages 630-635
    Published: October 25, 1994
    Released: February 19, 2009
    JOURNALS FREE ACCESS
    The relationship of exchange acidity y1, soluble silica and scab severity index of potato common scab was investigated. From a result of soil analytical data, potato common scab was suppressed with 7 to 8 of exchange acidity y1, that is a practical measure of exchangeable aluminum, by decreasing soil pH. However, potato common scab was not at high level suppression when the Si/Al mol ratio, values of the coefficients of correlation between soluble silica and soluble aluminum, were more than 0.5 at 7 to 8 exchange acidity y1. It comes to a conclusion that soluble silica influences the disease development of potato common scab to control a level of exchangeable aluminum in soil.
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  • Naoto YAMAOKA, Yoshimi MARUYAMA, Issei KOBAYASHI, Hitoshi KUNOH
    1994 Volume 60 Issue 5 Pages 636-639
    Published: October 25, 1994
    Released: February 19, 2009
    JOURNALS FREE ACCESS
    Frequencies of the formation and penetration of the short germ tubes of Erysiphe graminis conidia on barley coleoptiles, which were immersed in 0.01M CaCl2 solution (water condition) or floated on the same solution (air condition) were examined. Under air condition, short germ tubes were formed and penetrated barley coleoptile cells at a high frequency, while their formation frequency in water condition was significantly low, and if any, their penetration frequency was extremely low. These results suggest that the role of short germ tubes is most likely to take up water from host cells when conidia are exposured to the environment of low humidity, as reported by Carver and Bushnell (1983).
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  • Takashi TANAKA, Tomohiro KATOH, Yasuhisa FUJITA
    1994 Volume 60 Issue 5 Pages 640-643
    Published: October 25, 1994
    Released: February 19, 2009
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    To search the infection source of bacterial seedling blight of rice, we tried to isolate the pathogen, Pseudomonas plantarii, from weeds around the paddy field using the dilution plating method with modified medium of Azegami et al. in 1991. Weeds belonging to 28 genera within 16 families were collected in Mogami-machi, Yamagata Prefecture and used for the isolation. Twelve isolates obtained from kouyawarabi (Onoclea sensibilis), creeping buttercup (Ranunculus silerifolius), cranesbill (Geranium nepalense) and wild strawberry (Duchesnea chrysantha) formed the pathogenic bacterium-like colonies on the plate. The isolates induced the symptoms similar to those by the control strain to rice seedling and kouyawarabi. On the basis of their pathogenicity tests and bacteriological characteristics, the present isolates were identified as Pseudomonas plantarii Azegami et al. 1987. This is the first report that P. plantarii is isolated from weeds other than grasses.
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  • Shinji KOTANI
    1994 Volume 60 Issue 5 Pages 644-647
    Published: October 25, 1994
    Released: February 19, 2009
    JOURNALS FREE ACCESS
    Blast disease (Pyricularia zingiberi Nishikado) occurred on mioga and ginger plants, but not on plants such as Indian shell-flower (Alpinia japonica Miq.), ginger lily (Hedychium coronarium Koen.) and turmeric (Curcuma longa L.) which were growing around ginger fields. The blast fungus overwintered with sclerotium-like structures on the residues of diseased ginger and mioga plants. The overwintered sclerotium-like structures in ginger fields were killed by soil fumigation with methyl bromide which is commonly used before ginger planting season. The primary infection source of ginger plants seemed to be diseased mioga plants, because the first blast development occurred on the latter at the beginning of July, and then continually on the former.
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