Japanese Journal of Phytopathology
Online ISSN : 1882-0484
Print ISSN : 0031-9473
ISSN-L : 0031-9473
Volume 42 , Issue 5
Showing 1-17 articles out of 17 articles from the selected issue
  • Meisaku KOIZUMI
    1976 Volume 42 Issue 5 Pages 517-525
    Published: December 25, 1976
    Released: February 19, 2009
    JOURNALS FREE ACCESS
    Bacterial population and histological changes in leaf tissues of Citrus natsudaidai after inoculation of Xanthomonas citri by rubber-block press or infiltration method were examined.
    When inoculated by rubber-block press method, bacteria invaded intercellular spaces near substomatal chamber, but did not increase significantly until disease developed at cell levels. Staining with phenolic thionin and orange-G combination, elucidated that enlargement of nucleolus and disappearance of chloroplasts occurred in two or three layers of spongy parenchyma cells near stomata 4-5 days, 3-4 days, and 2-3 days after incubation at 20C, 23C, and 25C, respectively. Bacterial number increased for 1 or 2 days, then remained constant or decreased, and finally increased remarkably when diseased cells increased in number. The interval between these two phases of bacterial increase reflected the process of cellular damage. There was no noticeable difference in time interval between two phases of bacterial increase in leaf tissues among several host plants, including hosts of various resistance.
    When injected into spongy parenchyma, bacteria started to multiply soon after inoculation, especially when nutrients were added. Diseased cells, which were similar to those observed after rubber-block press inoculation, were found in one or two cell layers in spongy parenchyma 4 days after incubation at 20C, and extended to 4 to 5 layers 4 or 5 days later.
    Water-soaked spots appeared under the surface of the leaf when diseased cells increased to about 10 layers and hypertrophied. Cell division in affected tissues was not observed. There were numerous bacteria in the intercellular spaces and peripheral spaces of the diseased tissues.
    These results suggested that causal bacteria affect the adjacent parenchyma cells and disease them after a temperature-dependent incubation period, and that diseased cells support bacterial multiplication. These bacteria ooze out and affect surrounding host cells. Repetition of these process is considered to lead to symptom formation.
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  • Hiroshi FUJII
    1976 Volume 42 Issue 5 Pages 526-532
    Published: December 25, 1976
    Released: February 19, 2009
    JOURNALS FREE ACCESS
    Avirulent mutants of Xanthomonas oryzae occur during the course of successive culture on artificial media, and the population of these mutants gradually increases. In this experiment, mutual interference in multiplication between avirulent mutant (Av) and virulent wild type (V) in liquid media or inoculated rice leaves was studied. For the purpose of these studies, streptomycin resistant mutant from Av (Av-R), and that from V (V-R) were used frequently. Between Av and Av-R or between V and V-R, no difference could be found in virulence, colony morphology, lysotype, and bacterial physiology, except streptomycin resistance. Multiplication of V-R in liquid medium was markedly depressed by adding nearly the equal amount of Av. When V-R was mixed with Av and inoculated to rice leaves, lesion enlargement was inhibited in proportion to the amount of Av added. Multiplication of V-R in rice leaves was also inhibited by the addition of Av. Multiplication of Av-R in liquid medium was influenced very little by adding V. When Av-R was inoculated singly, it multiplied during 10-15 days within 2-3cm distance around the inoculated points, though no visible lesion was formed on the leaf. By mix-inoculation with Av-R+V, bacterial population of Av-R in leaves was much increased, and at the same time, Av-R was distributed within wider area in leaves.
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  • Hiroshi TOCHIHARA, Minoru TAMURA
    1976 Volume 42 Issue 5 Pages 533-539
    Published: December 25, 1976
    Released: February 19, 2009
    JOURNALS FREE ACCESS
    A survey of viruses was made on 26 field-grown samples of Japanese butterbur plant. Viruses were identified on the basis of symptomatology in indicator hosts, serology and particle morphology. Alfalfa mosaic virus, arabis mosaic virus and cucumber mosaic virus were found in 3, 9 and 22, respectively, out of 26 plants examined. In addition, a new virus was detected in 20 out of 26 samples and was named butterbur mosaic virus. Symptoms of butterbur caused by these viruses were studied by inoculating seedlings from true seeds. No clear leaf symptoms appeared on the butterbur plants upon inoculation with alfalfa mosaic virus or arabis mosaic virus, whereas inoculation with cucumber mosaic virus or butterbur mosaic virus resulted in mosaic leaves and in marked reduction of growth. Butterbur mosaic virus particles were filamentous and had a dimension of approximately 13×670nm. The virus was transmissible mechanically and was transmitted by an aphid, Myzus persicae, in a non-persistent manner. Its host plants were mostly confined to Compositae excepting Chenopodium quinoa, C. amaranticolor, petunia and beet.
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  • Akio TANII, Kuniyuki MIYAJIMA, Tadahiko AKITA
    1976 Volume 42 Issue 5 Pages 540-548
    Published: December 25, 1976
    Released: February 19, 2009
    JOURNALS FREE ACCESS
    The sheath brown rot is widely distributed and is the most important bacterial disease of rice plants in Hokkaido. The causal organism has been considered to be Pseudomonas marginalis (Brown) Stevens. The reexamination of the characteristics of this pathogen, however, elucidated that it differed in several characters from P. marginalis isolated from chinese cabbage and garlic. They were different each other in the bacteriological characters such as levan and 2-ketogluconate production, β-glucosidase and pectinase activities, acid production from sucrose, sorbitol, inositol, and other sugars, the host range, and serological relationships. Since no species resembling to this causal bacterium has been reported, we propose to name it Pseudomonas fuscovaginae A. Tanii, K. Miyajima et T. Akita sp. nov., on the basis of the characteristic sheath rot of rice plants.
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  • Takao GOTO, Takeshi TANIGUCHI
    1976 Volume 42 Issue 5 Pages 549-555
    Published: December 25, 1976
    Released: February 19, 2009
    JOURNALS FREE ACCESS
    Local lesions induced by an ordinary strain of tobacco mosaic virus (TMV-OM) appeared 8-12hr earlier than those by a bean strain of tobacco mosaic virus (TMV-B) both on Nicotiana glutinosa and on Nicotiana tabacum ‘Xanthi nc’. This was supported by the multiplication curves of the two strains. No difference was found in the time of local lesion appearance between intact TMV and its RNA for both the TMV-OM and TMV-B. When the inoculated plants which had been incubated at 32C for 2 or 3 days were transferred to 25C or when the inoculated leaves were treated with actinomycin D at 32C, local lesion by TMV-OM appeared 4.9-5.5hr earlier than those by TMV-B. These results suggest that the local lesion formation is composed of two distinct phases, a phase of virus multiplication and that of tissue degeneration, and that processes of these phases are both affected strongly by the genetic nature of the strains.
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  • Hiroshi YAEGASHI, T.T. HEBERT
    1976 Volume 42 Issue 5 Pages 556-562
    Published: December 25, 1976
    Released: February 19, 2009
    JOURNALS FREE ACCESS
    Heterothallic isolates of Pyricularia from crabgrass from the U.S.A. and from goosegrass and weeping lovegrass from Japan were used to study the effect of temperature, light, and culture media on perithecial production. The optimum temperature for perithecial production was about 20C for the crabgrass isolates and 22 to 25C for the goosegrass isolates. Although a few perithecia were occasionally produced by the goosegrass isolates in darkness, light was necessary for consistent perithecial production. A very low light intensity was sufficient to initiate perithecial production and short wavelengths (below 500nm) were most effective. Abundant perithecia were produced on oat meal agar and potato sucrose agar. The addition of zinc, methionine, and parts of various plants to modified Sachs agar increased perithecial production by the crabgrass isolates.
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  • Shigemitsu TORIYAMA
    1976 Volume 42 Issue 5 Pages 563-577
    Published: December 25, 1976
    Released: February 19, 2009
    JOURNALS FREE ACCESS
    Northern cereal mosaic virus (NCMV) initially infects phloem cells of the wheat plant. It spreads to mesophyll cells adjacent to the phloem and finally infects all cell types including phloem parenchyma cells, companion cells, sieve elements, developing xylem cells, mesophyll cells, guard cells and epidermal cells. NCMV was usually found accumulated within cisternae of the endoplasmic reticulum (ER) system in the cytoplasm. In some instances, the presence of NCMV particles within the nucleoplasm and perinuclear spaces was observed. A few particles of inner nucleocapsides (‘immature’ NCMV) were also seen within the cytoplasm. Budding profiles were rarely observed. NCMV seems to be enveloped by membranes almost simultaneously as inner nucleocapsides are formed. Initial appearance of NCMV in the cytoplasm was always associated with the formation of a viroplasm like inclusion. This viroplasm-like area (VpA) appeared as an electron dense matrix of granular or fibrous materials, which formed and distributed throughout the cytoplasm and sometimes occupied a large portion of it. At an early stage of infection, virus particles frequently appeared within the ‘non-denatured’ cytoplasm rather than at the periphery of the VpA. A few ‘immature’ particles were only occasionally observed within the VpA, while mature particles of NCMV were never seen scattered in the VpA. However, mature particles in aggregates were rarely found enclosed by the VpA. A second membraneous inclusion was also found in the cytoplasm of infected cells which exhibited an ellipsoidal structure and virus particles were frequently localized at the periphery of this inclusion. In infected mesophyll cells, membranes which protruded into central vacuoles were occasionally observed. Many ‘naked’ particles of NCMV were seen arranged in parallel between the membranes. Abnormal proliferation of Golgi vesicles (about 50-200nm in diameter) with an electron dense core were seen in the cytoplasm of young developing wheat leaves infected with NCMV, but disappeared as leaf stage progressed. The relation of these Golgi vesicles to stunting of wheat plant caused by NCMV infection is discussed.
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  • Minoru WATANABE, Kiyoto NAKANISHI
    1976 Volume 42 Issue 5 Pages 578-582
    Published: December 25, 1976
    Released: February 19, 2009
    JOURNALS FREE ACCESS
    A water soluble inhibitor of bacterial multiplication was produced in rice leaves inoculated with strains of Xanthomonas oryzae. In leaves inoculated with an incompatible strain the inhibitor became detectable within 24hr after inoculation, increased rapidly reaching the maximum amount by 8th day, then gradually decreased. In leaves inoculated with a compatible strain, on the contrary, the production of the inhibitor was not detected until the first lesion became visible, i.e. 5 days after inoculation, the inhibitor then increased gradually until the last stage of lesion enlargement, although the amounts produced were much smaller comparing with those in leaves inoculated with an incompatible strain. When the water extract from leaves responding with a resistant reaction was diluted to 1/2 and 1/4 concentrations with distilled water, inhibitory activity decreased correspondently, and almost disappeared by the dilution to 1/8 concentration. The water extract from the healthy leaves also showed a slight inhibitory action, but it disappeared by 1/2 dilution. Dialysis through cellophane membrane suggested that the inhibitor may be a low molecular substance.
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  • Hiroyuki YAMAMOTO, Toshikazu TANI, Hiroyuki HOKIN
    1976 Volume 42 Issue 5 Pages 583-590
    Published: December 25, 1976
    Released: February 19, 2009
    JOURNALS FREE ACCESS
    Blasticidin S completely supressed the resistance expression of Shokan 1 oat leaves to Puccinia coronata avenae race 226 when 5×10-6M aqueous solution of the chemical was supplied to the plants for 4hr from stem cut-ends from 8 or 12hr after inoculation. This blasticidin S effect was decreased as the initiation of the chemical supply was delayed to 14 or more hr after inoculation, and no effect was found by the supply after 24hr. The ratio of 14C-leucine incorporation into acid insoluble fraction to total uptake increased in the resistant-responding leaves to 1.2- to 1.35-fold of non-inoculated control, when the leaves were fed with 14C-leucine for 1 and 4hr from 14 to 24hr and 14 to 18hr after inoculation, respectively. No obvious increase in the ratio of incorporation was observed during the period of experiments in the leaves which were inoculated with compatible race 203. Blasticidin S markedly inhibited the incorporation of 14C-leucine into acid insoluble fraction in all cases including the blasticidin S treatment was initiated at 24hr after inoculation, in which no effect of blasticidin S on the resistance was detected. It was suggested that protein synthesis causally linked with resistance expression of Shokan 1 leaves to race 226 occurred between 14 and 24hr after inoculation. Peroxidase isozymes and phenylalanine ammonia-lyase activity increased in leaves inoculated with race 226, but the increases were not reduced by the blasticidin S treatment. It was assumed, therefore, that the resistance in this host-pathogen system involved the synthesis of protein(s) other than these enzymes.
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  • Shigeyuki MAYAMA, Jiko SHISHIYAMA
    1976 Volume 42 Issue 5 Pages 591-596
    Published: December 25, 1976
    Released: February 19, 2009
    JOURNALS FREE ACCESS
    The hypersensitive response was demonstrated as fluorescent collapsed cells in powdery-mildewed barley leaves with an aid of fluorescence microscopy. The fluorescent cells were formed in both epidermal and mesophyll cells, and these were exclusively found in incompatible barley. Papilla, halo, and lateral wall in the penetration sites were also detected with fluorescence, although, their response seemed to be nonspecific for resistance. When the parasite ceased growth at papillar stage, bright yellow autofluorescence was observed only in papilla and the adjacent cell wall within a radius of halo in infected epidermal cells. Those cells were not collapsed. When fluorescence was detected in entire areas of infected epidermal cells, the cells were collapsing, though mature haustoria were never found in those cells. The collapsed mesophyll cells shrinked and became multiangular, forming larger intercellular space in the infected leaf tissues. They were always fluorescent and considered to be dead because of the structural disintegration. In these cases, haustoria were usually formed in the epidermal cells above those collapsed cells. Cellular fluorescence observed in the transverse sections was emitted without any fluoresceins. Thus, it was suggested that the fluorescing compounds in papillae and these collapsed cells could be attributed to compounds other than callose which has been reported to accumulate in papillae.
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  • Hachiro OKU, Tomonori SHIRAISHI, Seiji OUCHI
    1976 Volume 42 Issue 5 Pages 597-600
    Published: December 25, 1976
    Released: February 19, 2009
    JOURNALS FREE ACCESS
    Pisatin was taken up by pea leaf cells when administrated through the epidermis-stripped mesophyll. The concentration, however, reduced with time elapsed, suggesting a metabolic degradation of pisatin. Pisatin thus administrated in early stage of infection prevented significantly the infection (formation of secondary hyphae) of Erysiphe pisi on pea leaves even at concentrations that had been proved non-inhibitory to this fungus. These results indicated that reassessment of phytoalexin as an infection inhibitor rather than antimicrobial substance is necessary for discussing it's role in the determination of host-parasite specificity and disease resistance.
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  • Yoshio YAMADA, Atsuko NAGASAWA
    1976 Volume 42 Issue 5 Pages 601-605
    Published: December 25, 1976
    Released: February 19, 2009
    JOURNALS FREE ACCESS
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  • Tsugio SASAKI
    1976 Volume 42 Issue 5 Pages 606-608
    Published: December 25, 1976
    Released: February 19, 2009
    JOURNALS FREE ACCESS
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  • Tomonori SHIRAISHI, Hachiro OKU, Seiji OUCHI, Mitsuko ISONO
    1976 Volume 42 Issue 5 Pages 609-612
    Published: December 25, 1976
    Released: February 19, 2009
    JOURNALS FREE ACCESS
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  • Koushi NISHIYAMA, Ryutaro SAKAI, Akinori EZUKA, Akitami ICHIHARA, Kuni ...
    1976 Volume 42 Issue 5 Pages 613-614
    Published: December 25, 1976
    Released: February 19, 2009
    JOURNALS FREE ACCESS
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  • Masaaki KATAOKA, Yukio SHIMIZU, Yasushi YASUDA
    1976 Volume 42 Issue 5 Pages 615-617
    Published: December 25, 1976
    Released: February 19, 2009
    JOURNALS FREE ACCESS
    Macroconidiospores similar to those of Phytophthora sp. was produced on the cucumber leaves infected with Pseudoperonospora cubensis (Berk. et Curt.) Rost., when the leaves were kept in contact with water during the formation of the conidiophore. The macroconidiospore discharged 15 to 25 zoospores similar in size to those produced from the normal conidiospores.
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  • Shigeyuki MAYAMA, Jiko SHISHIYAMA
    1976 Volume 42 Issue 5 Pages 618-620
    Published: December 25, 1976
    Released: February 19, 2009
    JOURNALS FREE ACCESS
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