Japanese Journal of Phytopathology
Online ISSN : 1882-0484
Print ISSN : 0031-9473
ISSN-L : 0031-9473
Volume 56 , Issue 2
Showing 1-19 articles out of 19 articles from the selected issue
  • Hisashi IWAI, Satoshi WAKIMOTO
    1990 Volume 56 Issue 2 Pages 177-184
    Published: April 25, 1990
    Released: February 19, 2009
    JOURNALS FREE ACCESS
    To clarify the cause of difference between soybean mosaic virus strains B (SMV-B) and D (SMV-D) in the ability of transmission through seeds, the mode of translocation, multiplication and inactivation of both SMV strains in a soybean was investigated. After soybean cultivar Hyuga was inoculated with each strain, virus concentration in the leaves and seeds was periodically assayed by bioassay and ELISA. When 3rd trifoliolate leaves were inoculated with two virus strains at V4 (4th node) stage, the concentration of SMV-D in the leaves upper than the inoculated leaves increased more vigorously and reached higher level than SMV-B on the 10th day after inoculation. After that, the concentration of both strains decreased with plant aging; that of SMV-D decreased more rapidly than SMV-B. On the 50th day after inoculation, both strains were faintly detected from the leaves lower than the inoculated leaves, and in these leaves also, decrease of SMV-D was faster than that of SMV-B. When inoculation was done to various leaves not extremely aged at different stages not later than R1 (beginning bloom stage), both SMV strains were readily translocated to the seeds set at the upper and lower nodes than the inoculated leaves. In conclusion, there was no significant difference of translocation patterns between two strains, but in every infected organ (leaf or seed) SMV-D disappeared more briefly than SMV-B.
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  • Hideyuki NAGAO, Kazuya HIRANO
    1990 Volume 56 Issue 2 Pages 185-193
    Published: April 25, 1990
    Released: April 03, 2009
    JOURNALS FREE ACCESS
    An orange mutant of Fusarium oxysporum (Schlecht.) emend. Snyd. et Hans. f. sp. cucumerinum Owen CH11200 (Foc) was obtained by ultraviolet irradiation. Pathogenicity, morphological features and some other properties of this mutant (T107) and its 15 single spore isolates relating to their survival in soil were compared with those of Foc. Microconidia of T107 were formed on the phialide. Productivity of microconidia of T107 and its 15 isolates on PSA was almost the same as that of Foc. The effect of temperature on growth of both Foc and T107 seemed to be similar. T107 survived in soil as chlamydospore and caused wilt of cucumber seedlings. It was proved that T107 had the same morphological and biological features and behaviors in soil as Foc. This orange mutant is considered to be suitable for ecological study on Fusarium oxysporum f. sp. cucumerinum.
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  • Tun-tschu CHANG, Wen-hsiung KO
    1990 Volume 56 Issue 2 Pages 194-198
    Published: April 25, 1990
    Released: February 19, 2009
    JOURNALS FREE ACCESS
    Two single-oospore isolates (1 A1 and 1 A2) of P. infestans formed oospores in sectors when grown on medium containing metalaxyl. Single-zoospore cultures obtained from the oospore sector of either isolate consisted of both A1 and A2 mating type. All the single-zoospore cultures from the non-treated isolates had the same mating type as the parent isolate. Metalaxyl also caused mating type change in 3 A1 isolates of P. parasitica. The conversion of A1 to A2 mating type by metalaxyl in infected host tissues is postulated as a possible origin of A2 isolates of P. infestans in Europe.
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  • Hiroyuki SAWADA, Hiroyuki IEKI, Yuichi TAKIKAWA
    1990 Volume 56 Issue 2 Pages 199-206
    Published: April 25, 1990
    Released: February 19, 2009
    JOURNALS FREE ACCESS
    Recently, the incidence of crown gall disease has been gradually increasing in some grapevine varieties including ‘Kyoho’ in Japan. Twenty-five bacterial isolates, which were obtained from the galls of grapevines collected in Iwate, Yamanashi, Nagano and Shimane Prefectures, were identified as Agrobacterium tumefaciens (Smith et Townsend 1907) Conn 1942 based on their ability to induce galls on grapevine, tomato and sunflower using the needle prick inoculation method and also based on 90 cultural, physiological and biochemical characteristics. Although the isolates differed from the reference strains belonging to A. tumefaciens biovars 1 and 2 in 15 and 14 characteristics, respectively, they were similar to biovar 3 with respect to the features presented in Bergey's Manual (1984) except for the cleavage of ethanol and propionate. Based on these results it was suggested that the isolates belonged to A. tumefaciens biovar 3.
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  • Chikara MASUTA, Yumiko HAYASHI, Wei Qin WANG, Yoichi TAKANAMI
    1990 Volume 56 Issue 2 Pages 207-212
    Published: April 25, 1990
    Released: February 19, 2009
    JOURNALS FREE ACCESS
    Four satellite RNA isolates of cucumber mosaic virus (CMV), S19-, T43-, T62- and T73-sat-RNAs were obtained from CMV-infected plants collected in Tochigi Prefecture of Japan. Their physical and biological properties were investigated. T43- and T62-satRNAs induced necrosis on tomato like Y-satRNA, whereas S19- and T73-satRNAs did not. T43-satRNA was found to be identical to T62-satRNA by nucleotide sequence determination. The sequences were compared with each other and with other satellite RNAs, revealing high degree of nucleotide sequence homology between S19-satRNA and Y-satRNA (91%) and between T43-satRNA and OY2-satRNA (94%). Further analyses of the three sequences indicate that no common open reading frame is present and thus, they do not seem to encode any protein products essential for their biological activity. Competition of the satellite RNAs with Y-satRNA was examined by mixed inoculations under the condition using tobacco as a host and CMV-O as a helper virus. The relative replication ability of T43-satRNA is superior to that of Y-satRNA while T73-satRNA is apparently similar to or a little better than Y-satRNA.
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  • Satoshi T. OHKI, Yasunari TAKAMI, Tadao INOUYE
    1990 Volume 56 Issue 2 Pages 213-218
    Published: April 25, 1990
    Released: February 19, 2009
    JOURNALS FREE ACCESS
    A comparative study on levels of viral infectivity, yield, double-stranded (ds) RNAs and coat protein was conducted for the symptomless leaves (S), green areas (G) and yellow areas (Y) of mosaic-affected leaves from tobacco plants inoculated with an isolate of cucumber mosaic virus (CMV) containing no satellite RNA. Levels of CMV infectivity in S and G were very low (1-2% of Y), which agreed with extremely low virus concentration in S and G (less than 1% of Y). However, total amounts of dsRNAs in S and G were relatively high (33-43% of Y). Gel electrophoresis showed that Y contained almost equal amounts of all four dsRNA species, while S and G contained equivalent amounts of dsRNAs 3 and 4 but no dsRNAs 1 and 2. Levels of coat protein in S and G were also very low (1-3% of Y). Throughout the growth of the symptomless leaves, the amounts of dsRNA species and coat protein remained virtually constant. Periodic detection of dsRNAs from newly developed leaves at the shoot tip revealed that the amounts of dsRNAs 3 and 4 were generally constant, whereas dsRNAs 1 and 2 were detectable only in the mosaic leaves appeared before and after the period in which the symptomless leaves developed.
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  • Kazusato OHSHIMA, Eishiro SHIKATA
    1990 Volume 56 Issue 2 Pages 219-228
    Published: April 25, 1990
    Released: February 19, 2009
    JOURNALS FREE ACCESS
    Total of one hundred and thirty-five antibody-secreting hybridomas were fused from luteovirus-immunized spleen cells. Hybridomas secreting monoclonal antibodies (MoAbs) for potato leafroll virus (PLRV), beet western yellows virus (BWYV) and tobacco necrotic dwarf virus (TNDV), were screened by four different procedures of enzyme-linked immunosorbent assay (ELISA). There are procedure 1; antigen adsorption ELISA (AAI-ELISA), in which purified virus in phosphate buffered saline (PBS) at pH 7.4 was adsorbed onto the microplate wells, procedure 2; AAI-ELISA in which purified virus in sodium carbonate-bicarbonate buffer (SCB) at pH 9.6 was adsorbed onto the microplate wells, procedure 3; indirect double antibody sandwich ELISA (IDAS-ELISA) in which polyclonal antibody was used as trapping antibody and purified preparations diluted in PBS-T (containing Tween-20) as antigens were used, procedure 4; IDAS-ELISA in which polyclonal antibody was used for trapping antibody and crude saps of virus infected plants in PBS-T as antigens were used. Based on the results, all of the antibody-secreting hybridomas can be screened by AAI-ELISA of procedure 1. On the other hand IDAS-ELISA is indispensable for screening virus-specific MoAbs. We recommend that combination of two ELISA procedures, such as AAI-ELISA of procedure 1 and IDAS-ELISA of procedure 4, will be used for the screening of luteovirus antibody-secreting hybridomas.
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  • Yoshiyuki TAKAHASHI, Kenichi TSUCHIYA, Kenichiro SHOHARA, Takahito SUZ ...
    1990 Volume 56 Issue 2 Pages 229-234
    Published: April 25, 1990
    Released: February 19, 2009
    JOURNALS FREE ACCESS
    To obtain monoclonal antibodies (MABs) specific to Pseudomonas cepacia (Pc) strain RB 425, the live cells (L) and the fixed cells (F) by glutaraldehyde were injected to mice, respectively. Sixteen and 8 hybridoma lines were established from L-immunized and F-immunized mouse, respectively. Three MABs from L-hybridoma lines and another 3 MABs from F-hybridoma lines were used for the specific detection and analyses of the epitopes on Pc. Although some of the 6 MABs of ascitic fluids showed almost the same titers as rabbit antisera in indirect ELI-SA, they had a limited ability to precipitate and agglutinate the L cells. The reactivity of the 6 MABs was tested with L, F, heated L (HL) and heated F (HF) cells in indirect ELISA. Three out of 6 MABs were heterospecific antibodies that reacted more strongly with HL cells than did with each immunogen. Three types of epitopes were classified by the reactivity of MABs with L and F cells. The specificity of MABs was detected by indirect ELISA. The live cells of 5 Pc strains, 6 pseudomonads species, and other bacterial genera were studied for their antigenicity. Five epitopes were distinguished by the reaction patterns of the MABs, and the specificity of the MABs was different in the 5 strains of Pc. Furthermore, 2 MABs from L-hybridoma lines showed a wide specificity in their reaction with pseudomonads, while the others reacted only with the strains of Pc.
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  • Issei KOBAYASHI, Miki SAKURAI, Akira TOMIKAWA, Toshio YAMAMOTO, Naoto ...
    1990 Volume 56 Issue 2 Pages 235-242
    Published: April 25, 1990
    Released: February 19, 2009
    JOURNALS FREE ACCESS
    Factor (s) associated with the degree of resistance of tomato cultivars to the fruit rot caused by Fusarium oxysporum f. sp. lycopersici race J3 (J3: currently proposed to be revised as F. oxysporum f. sp. radicis-lycopersici) were examined by physiological and microscopical means. No significant differences in hyphal growth were found when the fungus was inoculated on the cut surfaces of fruits or in juice of fruits of a susceptible (Mie First) and a resistant cultivar (Zuiken). These results suggest that components of fruits might not be involved in the resistance of the resistant cultivars. Light microscopic observations demonstrated that hyphae grew in styles of both cultivars similarly for the first 4 days after inoculation. Their growth, however, stopped in styles of Zuiken thereafter, but not in Mie First. Thus, some factor (s) in styles of Zuiken might affect the growth of hyphae, leading to the resistance of this cultivar. Electron microscopy revealed that hyphae grew in middle lamellae of conducting tissues of styles. In Mie First, middle lamellae in infected areas of styles were degenerated almost completely by 6 days after inoculation, and thus the remaining cell walls were left arranging side by side. In contrast, middle lamellae and cell walls in infected areas of Zuiken swelled but were not completely degenerated by 6 days after inoculation. These results suggest a possibility that differences of structural and chemical components in styles might account for varied degrees of resistance of both cultivars.
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  • Hiroshi TANAKA, Hideaki NEGISHI, Hatsue MAEDA
    1990 Volume 56 Issue 2 Pages 243-246
    Published: April 25, 1990
    Released: February 19, 2009
    JOURNALS FREE ACCESS
  • Katsumi OGAWA, Shinichi TAKEDA
    1990 Volume 56 Issue 2 Pages 247-249
    Published: April 25, 1990
    Released: February 19, 2009
    JOURNALS FREE ACCESS
    Sensitivity to Benomyl of Bakanae pathogen, Gibberella fujikuroi, on diseased rice plants was surveyed in Iwate Prefecture from 1980 to 1987. A highly resistant isolate was discovered first in 1980 and gradually increased as well as moderately resistant isolates for the next 8 years. In 1985, both of the sensitive and resistant isolates coexisted on the same diseased sheath blade of rice plant, but in 1987 most of the isolates were highly resistant with minimum inhibitory concentration of equal to or more than 1, 000μg/ml. Such rapid development of resistance to benomyl in G. fujikuroi may be caused by successive application of this chemical as seed disinfectant.
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  • Hiroki YAMAMOTO, Toshiro TERADA, Takahiko NAGANAWA, Kadzunori TATSUYAM ...
    1990 Volume 56 Issue 2 Pages 250-251
    Published: April 25, 1990
    Released: April 03, 2009
    JOURNALS FREE ACCESS
  • Tokuji FUKUDA, Koji AZEGAMI, Hideo TABEI
    1990 Volume 56 Issue 2 Pages 252-256
    Published: April 25, 1990
    Released: February 19, 2009
    JOURNALS FREE ACCESS
    The causal bacteria of bacterial black node of barley and wheat, Pseudomonas syringae pv. japonica, invaded the leaf blade, leaf sheath, internode, node, awn, palea and lemma through the stomata, multiplied in the intercellular spaces of parenchyma, but never invaded the vascular bundles of infected plants. Brownish black lesions spread widely in spite of limited location of the bacterial multiplications in the parenchyma. In case of the palea, stomata existed on both sides of them, and they were connected with each others through the intercellular space of parenchyma. Thus, in the palea tissue, bacteria are able to move from one side to another side. This infection process is regarded as a main cause of the seed-borne mechanism of this disease. The causal bacteria infected the palea and lemma at first, then invaded the caryopsis through the funiculus, and multiplied in the intercellular spaces of parenchyma of caryopsis, but no bacteria were observed in the vascular bundles.
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  • Satoshi KASHIWAZAKI, Kou SHIMAZU, Tsuneo TSUCHIZAKI
    1990 Volume 56 Issue 2 Pages 257-260
    Published: April 25, 1990
    Released: February 19, 2009
    JOURNALS FREE ACCESS
  • Tomonori SHIRAISHI, Naohiro HORI, Tetsuji YAMADA, Hachiro OKU
    1990 Volume 56 Issue 2 Pages 261-264
    Published: April 25, 1990
    Released: February 19, 2009
    JOURNALS FREE ACCESS
  • Akira TOMIKAWA, Issei KOBAYASHI, Miki SAKURAI, Toshio YAMAMOTO, Naoto ...
    1990 Volume 56 Issue 2 Pages 265-268
    Published: April 25, 1990
    Released: February 19, 2009
    JOURNALS FREE ACCESS
  • Mitsuo WATABE
    1990 Volume 56 Issue 2 Pages 269-272
    Published: April 25, 1990
    Released: February 19, 2009
    JOURNALS FREE ACCESS
    Immunofluorescent antibody technique is a useful method for detecting Phytophthora. But the autofluorescence and the nonspecific staining of soil particles interfere with the detection of the fungi in soil. This paper reports that the pretreatment of the samples with gelatin-rhodamine conjugate prevented the samples from the autofluorescence and the nonspecific staining and therefore permitted the Immunofluorescent antibody staining in soil. Stained Phytophthora was easily detected on the yellow-orange background.
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  • Yoshikatsu FUJITA, Ryoichi SONODA, Hiroshi YAEGASHI
    1990 Volume 56 Issue 2 Pages 273-275
    Published: April 25, 1990
    Released: February 19, 2009
    JOURNALS FREE ACCESS
    The different lesion-type isolates of incompatible races of Pyricularia oryzae were used to compare the potential for suppressing leaf blast by pre-inoculation to rice plants. Although the leaf blast was suppressed by pre-inoculating any incompatible isolate of blast fungus, there were some differences in the degree of leaf blast suppression among the isolates used. The highest suppression of leaf blast was observed when the isolates inciting the quite small eyespots with brown margins (bg-type) were pre-inoculated to rice plants.
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  • Daijiro HOSOKAWA, Minoru WATANABE, Kanichi MORI
    1990 Volume 56 Issue 2 Pages 276-280
    Published: April 25, 1990
    Released: February 19, 2009
    JOURNALS FREE ACCESS
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