Japanese Journal of Phytopathology
Online ISSN : 1882-0484
Print ISSN : 0031-9473
ISSN-L : 0031-9473
Volume 60 , Issue 4
Showing 1-20 articles out of 20 articles from the selected issue
  • Triwidodo ARWIYANTO, Masao GOTO, Shinji TSUYUMU, Yuichi TAKIKAWA
    1994 Volume 60 Issue 4 Pages 421-430
    Published: August 25, 1994
    Released: February 19, 2009
    JOURNALS FREE ACCESS
    Bacteriocinogenic strelitzia strain (Str-10) of Pseudomonas solanacearum was tested for its ability to suppress development of bacterial wilt of tomato in a greenhouse. The spontaneous avirulent mutant of strain Str-10 i.e. strain Str-10 op type, significantly protected tomato plants from bacterial wilt. The strain suppressed the development of bacterial wilt incited either by bacteriocin-sensitive or bacteriocin-resistant strains. The protection was more pronounced when the temperature was low (18-25°C). However, at high temperature (30-37°C) the protection effect was lost. Population of strain Str-10 op type was maintained in the rhizosphere and rhizoplane. At 28 days after inoculation, population of strain Str-10 op type in the rhizoplane was 2×106cfu/g fresh weight of root and 2×105cfu/g dry weight of soil in the rhizosphere. The bacterium also invaded root and stem tissue a few centimeters above ground. The promising protection due to the strain Str-10 op type was obtained when the population ratio of the challenge strains to Str-10 op type was smaller than 1. Although the strain Str-10 op type exists in the greater amount in the root system, the bacteriocin was unlikely involved in suppression of bacterial wilt of tomato. The ability of strain Str-10 op type in suppressing the development of bacterial wilt was presumed to be derived from induced resistance of host plant.
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  • Pyoyun PARK, Tohgo OHNO, Syoyo NISHIMURA, Keisuke KOHMOTO, Hiroshi OTA ...
    1994 Volume 60 Issue 4 Pages 431-440
    Published: August 25, 1994
    Released: February 19, 2009
    JOURNALS FREE ACCESS
    The membranous fragments between cell walls and plasma membranes were examined ultrastructurally, quantitatively, and histochemically in water- or AK-toxin-treated susceptible Japanese pear leaves fixed with the conventional double fixation (GA-Os) method using glutaraldehyde (GA) and osmium tetroxide (OsO4) or the special, single mixing fixation (GA+Os) method using a mixture of GA and OsO4. Irrespective of chemical fixation used, two types of membranous fragments, myelinated and vesiculated fragments, appeared in the water- or toxin-treated leaves although the volume varied in the treatments. GA-Os method produced considerable volume of membranous fragments in the water-treated leaves while GA+Os method was effective to suppress extremely the occurrence. The results showed that the membranous fragments of the water-treated leaves fixed with GA-Os method were artifact. Even by using the improved fixation GA+Os method, the membranous fragments were found abundantly in the toxin-treated leaves, but rarely in the water-treated ones. The results indicated that the membranous fragments were induced by the results of the toxin treatment. The formation-mechanism, histochemical and ultrastructural natures, pathological significance of these membranous fragments was discussed in this study.
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  • Norio SATO
    1994 Volume 60 Issue 4 Pages 441-447
    Published: August 25, 1994
    Released: February 19, 2009
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    When the sporangia of Phytophthora infestans washed twice in distilled water were tested for indirect germination at 14°C, they did not germinate well (9% in 3hr) in distilled water, while in the tap water of Hokkaido Natl. Agric. Exp. Stn., they germinated well (78% in 3hr). Since some inorganic ions in the tap water appeared effective, various concentrations (0.01-10mM) of the salts, CaCl2, Ca(NO3)2, MgCl2, MgSO4, KCl, K2SO4, NaCl and Na2SO4, were evaluated for the effectiveness on indirect germination. Sporangial suspensions were preincubated for 22hr at 22°C for sporangial maturation and postincubated at 14°C for indirect germination. The most effective solution was 0.3mM CaCl2 (71% germination in 1hr), followed by 0.3mM MgSO4 (65%). Potassium and sodium salts were not very effective (<23%). At the cation concentration of 10mM all the salts except Na2SO4 inhibited indirect germination (0-5%). Hydrogen ion concentration markedly affected indirect germination, optimum at pH 8.0 (90% germination at 0.1mM CaCl2) but completely inhibitory at pH 4.5 (0%). Considering the results and the cations contained in the tap water, a synthetic salts solution favorable for indirect germination was devised: 0.2mM CaCl2, 0.05mM MgSO4, 0.05mM KH2PO4, 0.5mM NaHCO3, 0.01mM Fe-EDTA-Na. Using this solution the effect of sporangial concentration on indirect germination was also investigated. Sporangial suspensions below 2.5×104 sporangia/ml were favorable for indirect germination (≥97% in 2hr) but those above 105 were not.
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  • Norio NISHIMURA, Kazuichi KUDO
    1994 Volume 60 Issue 4 Pages 448-453
    Published: August 25, 1994
    Released: February 19, 2009
    JOURNALS FREE ACCESS
    The forma specialis and cultural and morphological characters of a F. oxysporum, the dry rot pathogen of taro (Colocasia esculenta), were examined. No forma specialis which corresponded to the family Araceae has been reported. The host range of the dry rot pathogen differed from that of the following 17 formae speciales: lycopersici race 2, melongenae, cucumerinum, melonis, niveum, lagenariae, conglutinans, cepae, allii, asparagi, arctii, batatas, spinaciae, fabae, fragariae, radicis-lycopersici and raphani. As a result, it was proposed to establish a new forma specialis, Fusarium oxysporum f. sp. colocasiae, and rename the disease “wilt” to differentiate this disease from taro dry rot caused by F. solani f. sp. radicicola.
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  • Kazuyuki MISE, Masashi MORI, Hitoshi NAKAYASHIKI, Takeshi KOYAMA, Tets ...
    1994 Volume 60 Issue 4 Pages 454-462
    Published: August 25, 1994
    Released: February 19, 2009
    JOURNALS FREE ACCESS
    The complete nucleotide sequence of a set of cDNA clones designated KU1 strain, from which infectious in vitro transcripts can be transcribed, of the ATCC66 strain of brome mosaic virus (BMV) was determined and compared with the Russian strain of BMV in both nucleotide and the deduced amino acid sequence. Each corresponding genomic RNA in the KU1 strain and the Russian strain was homologous by more than 97% in nucleotide sequence. Base substitution of the transition type was more frequent than that of the transversion type in all three genomic RNAs. Amino acid changes in three regions where significant amino acid sequence homology is shown among the Sindbis-like plant RNA viruses were mostly substitutions for amino acids categorized to similar groups. The nucleotide sequence of the 5′ noncoding region in RNA1 and RNA3 was identical in the corresponding RNAs of the two strains while seven base changes were observed in RNA2. Any base change in the 3′ noncoding region did not disrupt a predicted secondary structure. Two adjacent adenine residues were absent in the noncoding leader sequence of the coat protein gene of both KU1 strain and ATCC66 strain. The intercistronic oligo(A) tract in RNA3 of the ATCC66 strain was heterogeneous in length in which more than two guanine residues were observed by direct RNA sequencing, while one guanine residue was present in the RNA3 of the cDNA clone of the KU1 strain.
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  • Kazuhiko NARISAWA, Hirotaka MINAKAWA, Yuichi YAMAOKA, Keizo KATSUYA
    1994 Volume 60 Issue 4 Pages 463-468
    Published: August 25, 1994
    Released: February 19, 2009
    JOURNALS FREE ACCESS
    Axenic cultures of Puccinia recondita f. sp. tritici were established by placing aseptic leaf segments with spermogonia on artificial media. Good growth of colonies was observed on the medium which contained 25% concentration of Murashige and Skoog's minerals, vitamins, and glycine; sucrose, 40g; 2, 4-D, 0.001g; kinetin, 0.0001g; peptic peptone, 4g and bacto agar, 8g per liter. The colonies of the axenic cultures were white to yellow and felty to fluffy in appearance and consisted of narrow and straight hyphae. Microscopic observation and determination of the DNA content of the nucleus in hyphal cells showed that the cultures were haploid and uninucleate.
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  • Masayuki SANADA, Riyoko T. ITOH, Hidetoshi SHIMOKAWA, Kamehisa MATSUSH ...
    1994 Volume 60 Issue 4 Pages 469-477
    Published: August 25, 1994
    Released: February 19, 2009
    JOURNALS FREE ACCESS
    When the leaves of Nicotiana tabacum L. cv. White Burley were inoculated with a tomato strain of tobacco mosaic virus (TMV-T), activity of β-1, 3-glucan hydrolase was increased, but not with an ordinary strain of TMV (TMV-OM) and mechanical injury. An increase of the enzyme activity in uninoculated upper leaves of the same plants in which the lower leaves were inoculated with TMV-T, was positively correlated with acquired systemic resistance to TMV-T. Both sizes and numbers of local lesions produced on challenge-inoculated upper leaves decreased to about 30% of the control. However, when the inoculated lower leaves were cut off the 2nd day after TMV-T inoculation, no increase of the enzyme activity and systemic resistance in the upper leaves was observed. The enzyme activity was increased when detached half-leaves of the same plant were incubated on sodium salicylate solution, and showed a resistance to inoculated TMV-T. Furthermore, the enzyme activity was increased in the upper leaves of the same plant in which the lower leaves were injected with sodium salicylate and such the upper leaves showed the resistance to TMV-T. Polyacrylamide gel electrophoresis of the enzyme extracts from both the leaves inoculated with TMV-T and the leaves with induced resistance showed the presence of two isozymes of the glucan hydrolase. The involvements of salicylate on the increase of the enzyme activity and acquisition of the resistance to TMV-T are discussed.
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  • Katsunori TAMURA, Tohru TERAOKA, Daijiro HOSOKAWA, Minoru WATANABE
    1994 Volume 60 Issue 4 Pages 478-482
    Published: August 25, 1994
    Released: February 19, 2009
    JOURNALS FREE ACCESS
  • Hirotaka DATE, Hideo NASU, Motomu HATAMOTO
    1994 Volume 60 Issue 4 Pages 483-486
    Published: August 25, 1994
    Released: February 19, 2009
    JOURNALS FREE ACCESS
  • Susumu TAKAMATSU, Bo-Nian LIN, Hideo FURUTA, Koichi MAKARA
    1994 Volume 60 Issue 4 Pages 487-490
    Published: August 25, 1994
    Released: February 19, 2009
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  • Shin-ichi ITO, Shogo YANO, Shuhei TANAKA, Mitsuro KAMEYA-IWAKI
    1994 Volume 60 Issue 4 Pages 491-495
    Published: August 25, 1994
    Released: February 19, 2009
    JOURNALS FREE ACCESS
  • Hitoshi NAKAYASHIKI, Kappei KOBAYASHI, Seiji TSUGE, Tetsuro OKUNO, Iwa ...
    1994 Volume 60 Issue 4 Pages 496-500
    Published: August 25, 1994
    Released: February 19, 2009
    JOURNALS FREE ACCESS
  • Hiroyuki IEKI
    1994 Volume 60 Issue 4 Pages 501-506
    Published: August 25, 1994
    Released: February 19, 2009
    JOURNALS FREE ACCESS
    Fifty-nine isolates of Elsinoë fawcetti Jenkins were obtained from scab pustules of diseased leaves collected from 10 citrus fields in Ehime, Oita and Miyazaki Prefectures where it was reported that scab control with the spray of benzimidazole fungicides was not effective. These isolates were classified into four types as follows: i) sensitive type which does not grow on PDA medium containing benomyl 1μg/ml, ii) weakly resistant type grows on benomyl 1μg/ml, iii) intermediately resistant type grows on benomyl 50μg/ml, and iv) highly resistant type grows on benomyl 500∼1, 000μg/ml. The normal spray concentration of benomyl (250μg/ml) not effective for the control of scab disease in potted citrus nursery plants inoculated with isolates displaying intermediate or high resistance. On the other hand, in the case of isolates with weak resistance, the control was slightly less effective than in the case of sensitive isolates. Isolates with weak and intermediate resistance levels grew on PDA medium containing a higher concentration of a mixture of diethofencarb and thiophanate-methyl (DET) as compared with the highly resistant isolates. Both dithianon (D) and the mixture of dithianon and thiophanate-methyl (DT) were effective in the control of the growth of mycelial colonies on medium in the case of three types of isolates resistant to benzimidazole. The DET, DT and D fungicides showed effective control in the experiment using potted citrus nursery plants which were inoculated with highly resistant isolates.
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  • Mitsuo KAWARADANI, Shin'ichi KUSAKARI, Shinroku MORITA, Yutaka TANAKA
    1994 Volume 60 Issue 4 Pages 507-513
    Published: August 25, 1994
    Released: February 19, 2009
    JOURNALS FREE ACCESS
    The diagnosis at early stages of infection with soil-borne pathogens in eggplant was tried by the measurement of enzyme activities in leaves. The leaves of eggplants were inoculated with Verticillium dahliae, Fusarium oxysporum f. sp. melongenae and Pseudomonas solanacearum and the enzyme activities of peroxidase, polyphenol oxidase, phenylalanine ammonia lyase, β-1, 3-glucanase (Glc), superoxide dismutase (SOD), polygalacturonase, pectin methylesterase and amylase (Amy), were measured. The leaves of eggplant infected with V. dahliae showed higher activities of Glc and Amy than the healthy and the other diseased leaves. The Amy activity of the leaves infected with F. oxysporum was slightly higher than that of healthy leaves, but the difference between the Amy activities of the leaves infected with F. oxysporum and P. solanacearum was not clear. The leaves of eggplant infected with P. solanacearum showed higher activity of SOD. The usefulness of the measurement of enzyme activities for a rapid diagnosis for diseases was discussed.
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  • Masahiro YOSHIDA, Kenzo KOBAYASHI
    1994 Volume 60 Issue 4 Pages 514-522
    Published: August 25, 1994
    Released: February 19, 2009
    JOURNALS FREE ACCESS
    Morphogenesis of the pathogenic Streptomyces sp. causing root tumor of melon was characterized with growing process from spore germination to sporulation and pseudosporangium formation on the yeast-starch agar medium under optical and scanning electron microscope observation. Spores did not germinate within 1hr incubation, and then just a few spores were beginning to germinate with 3hr incubation at 28°C. Most of spores germinated after 24hr incubation, but there were remained ungerminated ones. Especial changes of spore surface structure were not observed during germination except that the spores had swollen until 3hr incubation. Germ tube (hypha) appeared from 1-3 points of a spore surface. Branched multiplying hyphae formed colonies of substratal mycelia after 24-48hr incubation. Besides growing hyphal tips of these mycelia were become swelling, and produced hook-shaped aerial hyphae on the colonies. The aerial hyphae were more swelled and formed itself into hook or open-loop shapes at 72hr incubation. Ripening aerial mycelia developed into not only spore chains by formation of septa but also pseudosporangia consisting of spore chains from 72hr to 5 days after incubation. Morphology of the spore chains indicated that it belonged to type of retinaculum-apertum. Then these colonies had been increasing number of pseudosporangia and decreasing number of spore chains with the incubation time. Pseudosporangia covered with mucoid-like substances were recognized in matured ones after 10 days incubation. For 14-21 days incubation, these colonies had been maintaining the condition that could be observed pseudosporangia, spore masses and spore chains on the substratal mycelial mats overspread with mucoid-like substances.
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  • Kazunori ICHIKAWA, Toyozo SATO
    1994 Volume 60 Issue 4 Pages 523-526
    Published: August 25, 1994
    Released: February 19, 2009
    JOURNALS FREE ACCESS
    A new disease of aster was found in Yamanashi Prefecture, Japan, 1989. Dark brown or tan-colored spots with dark margin appeared on the leaves, stems and flower buds of the host. A species of Stemphylium isolated from the lesions was pathogenic to asparagus, tomato, soybean, stone leek and onion as well as aster. The pathogen was identified as S. vesicarium from its conidial morphology and host range. The fungus is new in Japan and aster is new host for it.
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  • Shinji KOTANI
    1994 Volume 60 Issue 4 Pages 527-530
    Published: August 25, 1994
    Released: February 19, 2009
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    The effects of temperature on formation and germination of sclerotium-like structures (SLS) and conidia, and penetration of Pyricularia zingiberi Nishikado into host cells were investigated. Maximum temperature for SLS formation was 23°C on potato carrot agar, and SLS on the residues of mioga plants produced easily conidiophores and conidia at 32°C. Abundant conidia were also produced on the surface of infected ginger leaves at 28°C, and the optimum temperature for conidial germination was 30°C in nutrient solution. Optimum temperature range for appressorial formation was 20-23°C on the leaf epidermis of ginger. Optimum temperature range of penetration from the appressoria was 25-28°C.
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  • Koji KAKUTANI, Hideyoshi TOYODA, Sachio GOTO, Seiji OUCHI
    1994 Volume 60 Issue 4 Pages 531-534
    Published: August 25, 1994
    Released: February 19, 2009
    JOURNALS FREE ACCESS
    Virulent bacteriophages (phages) were isolated from a field soil infested with the host bacterium, Pseudomonas solanacearum (strain K-101) and examined for their physical and chemical properties. The phages were classified into two types on the basis of their plaque morphologies (small obscure or large clear plaques against the indicator bacterium K-101), and the phages were isolated and purified through a series of plaque isolation. An electron microsopic observation indicated that the phage isolate forming a small plaque had a polygonal head with three tails and the other a smaller head with two tails. The electrophoretic patterns of DNA fragments obtained by the digestion with some restriction endonucleases were completely different between these two types of isolated phages. The RFLP was detected among the small plaque-forming phage isolates, although there was no difference in morphology of phage particle and infectivity against some different strains of the host bacterium.
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  • Toyozo SATO, Hiroshi SHIOTANI, Seiji UEMATSU, Masanobu KOBAYASHI, Yasu ...
    1994 Volume 60 Issue 4 Pages 535-539
    Published: August 25, 1994
    Released: February 19, 2009
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    In 1991 and 1992, the black rust of a gipsy type cultivar of carnation caused by Puccinia arenariae was found in Chiba and Kanagawa Prefectures. Teliospore germination and basidiospore formation of the pathogen were most vigorous under 15-20°C. The pathogen was confirmed to be a microcyclic rust fungus without spermogonia and to produce 2-celled basidia. It was proved to attack 4 species of caryophyllaceous weeds as well as the cultivar by inoculation with teliospores.
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  • Takefumi IKEDA, Tadao TODA, Masahiro TAJIMA
    1994 Volume 60 Issue 4 Pages 540-542
    Published: August 25, 1994
    Released: February 19, 2009
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    Responses of different resistant families of Pinus thunbergii and P. densiflora to the pine wood nematode (Bursaphelenchus xylophilus) were investigated from the view points of xylem water conductance and histological features. Survived pine seedlings after inoculation with pine wood nematodes reacted to the nematode invasion independent of the strength of resistant families as follow: partial loss of xylem water conductance caused by embolism, destruction and degeneration of parenchyma cells in dysfunctional xylem area, and normal parenchyma cells and cambium in functional xylem area. These reactions are the expression of resistance of P. thunbergii and P. densiflora to pine wood nematode invasion.
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