Japanese Journal of Phytopathology
Online ISSN : 1882-0484
Print ISSN : 0031-9473
ISSN-L : 0031-9473
Volume 22 , Issue 4-5
Showing 1-23 articles out of 23 articles from the selected issue
  • Hazime YOSHII, Shigeo YAMAMOTO
    1957 Volume 22 Issue 4-5 Pages 169-172
    Published: December 31, 1957
    Released: April 21, 2009
    1) The bath water seed disinfection method, which is widely used in Japan for the control of loose smut of wheat, Ustilago tritici, is as follows: After temperature of the bath water has risen to 45° or 46°C., the oven fire is put out. Wheat seed in a package is suspended in the hot water in a container with a slightly opened lid for about ten hours until the water temperature descends down to about 25°C. 2) Present experiments were carried out to ascertain the rate of decrease of water temperature under above stated method with bath-tubs of several different structures and water depths, and the time required for seed soaking for the control of loose smut of wheat. Three kinds of bath-tubs were used, namely, a mortar-tub, directly, heated with side oven, an iron-tub directly heated from below, and the common wooden-tub directly heated with side oven. Each of them had about 300 liters capacity. Wheat seed which had been inoculated with the fungus by the partial vacuum method of Oort was used. 3) The results obtained were as follows: i) The rate of temperature decrease at a definite time was proportional to the temperature of bath water at that time. ii) In case when the quantity of water was larger the rate of temperature decrease was smaller. iii) When the initial temperature of hot water was kept between 46°C. to 50°C., and the bath-tubs were filled with water, the difference of the rate of temperature fall due to the structure of bath-tubs was not so great as to disturb the practical use of the bath water soaking method. iv) It was found that five hours' soaking was sufficient for the control of the loose smut of wheat in case the initial temperature was kept at 46°C. v) No ill-effect for the germination of wheat seed was found when the initial temperature of bath water was kept at 46°C. and the fire was put out, even if the seed was soaked for ten hours.
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  • Sakae TOYODA, Naoji SUZUKI
    1957 Volume 22 Issue 4-5 Pages 173-177
    Published: December 31, 1957
    Released: April 21, 2009
    This paper deals with the changes in the respiration of leaf tissues infected by Piricularia oryzae. Rice varieties, Aiti-asahi (susceptible) and Kanto 53 (resistant) were used. Leaf lesions occurring on these varieties were classified into 5 types as shown diagramatically in Fig. 1. Lesions of the types 3, 4 and 5 were used for the experiments. Types 4 and represent the lesions on the susceptible var5ety and type 3 represents the lesion on the resistant variety. From each lesion, the central necrotic area is removed and a marginal zone of about 3mm width was taken as the material for measurement of the respiration rate. If the tissue is resistant, the respiration is stimulated to some extent, not exeeding over two times as that of non-infected tissue, while f the tissue is susceptible, the respiration is stimulated up to 4 to 5 times. The RQ gives usually 0.8 in the healthy, and 0.9 in the infected tissues. The diminution of Pasteur effect (shown by QairCo2/QN2Co2) is remarkeble in the susceptible tissue, but in the resistant tissue it is not affected. The respiration of resistant tissue is inhibited by 10-25 per cent by such metal enzyme inhibitors as NaN3, 8-hydroxyquinoline, and salicylaldoxime, while, that of susceptible tissue is not affected, suggesting that flavoprotein enzyme works as terminal oxidase in the infected tissue, in place of metal protein enzymes. The above mentioned change of terminal oxidase system in the infected tissue is probable because it is already known that P. oryzae produces two toxins, α-picolinic acid. and piricularin and that these are inhibitory to metal enzymes (Tamari et al.). The writers consider that the main cause of unusual stimulation of respiration and the diminution of Pasteur effect in susceptible tissue is the change of terminal oxidase, from metal protein to flavoprotein.
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  • Yasuji ASADA
    1957 Volume 22 Issue 4-5 Pages 178-182
    Published: December 31, 1957
    Released: July 21, 2010
    The present paper deals with some physiological observations on the normal and the Akiochi (autumn-decline) rice plants affected with Cochliobolus miyabeanus. 1. Healthy and affected leaves of the both plants were immersed in the culture filtrate of C. miyabeanus, and the change of their weight and the amount of nitrogen dissolved in media were measured. Healthy leaves of normal plant and affected leaves of Akiochi plant showed the decrease of leaf weight as well as the much amount of soluble nitrogen, but affected leaves of normal plant was not. The nitrogen in diseased part of normal rice plant, therefore, seems to be changed in the insoluble form. 2. Changes of thiamine contents and thiamine-destroyed substances in rice plant accompanied with the infection were observed. Thiamine, which is the essential substance for the growth of C. miyabeanus, is much contained in the Akiochi leaves, but in the normal leaves it is remarkably destroyed at the early stage of the infection. There is a little destruction of thiamine in Akiochi rice leavei. 3. Accompanying with the infection, respiration is increased in the both plants. In normal rice leaves the oxidative phosphorylation caused by respiration takes place more effectively, but in Akiochi leaves it is not so effective and substrates of respiration are uselessly consumed. 4. Diseased spot is not enlarged, when it is kept in the oxygen free condition.
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  • Tomomasa MISATO, Itaru ISHII, Masaru ASAKAWA, Kazuo FUKUNAGA
    1957 Volume 22 Issue 4-5 Pages 183-187
    Published: December 31, 1957
    Released: April 21, 2009
    (1) Piricularia oryze was used as the most senstive test organism of microassaying some antifungal antibiotics by the cup or the paper disc method. Spores of P. oryzae were obtained by cultivating the organism on the yeast starch agar slants at 28°C for 2 weeks. The concentration of spores in the assay medium necessary for optimum results was about 17 -34×104 spores per ml (Fig. 3).
    (2) A Study was made on the factors affecting the Blasticidin assay. The most important factors to be controlled in the assay of Blasticidin were hydrogen ion concentrations of the assay medium . and of the sample solutions. As shown in Fig. 1 and 2, Blasticidin gave the highest activity against P. oryzae at pH 5.0 in both of them.
    (3) The cup method for assaying Blasticidin was established. The assay medium was as follows: Soluble starch 10g, yeast extract 1g, agar 15g and 0.1M PO4 buffer of pH 5.0 1, 000 ml. The sample solutions were made with 0.1 M PO4 buffer of pH 5.0. As shown in Fig 4, the excellence of log dose-response curve and its linearity within the range of 0.2-2.0mcg/ml warrants the use of the cup method.
    (4) The paper disc method was adapted to the assay of Antimycin A and Blastmycin. The assay media were made with distilled water. Samples were dissolved in methanol The linear relations were found between the diameters of inhibition zones and the log concentrations within the ranges of 0.05-5.0mcg/ml of Antimycin A and 0.05-0.5mcg/ml of Blastmycin. The potency are calculated on the basis of this relation.
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  • Zyun HIDAKA, Hisatomi MURANO, Isao KAMIYAMA
    1957 Volume 22 Issue 4-5 Pages 188-192
    Published: December 31, 1957
    Released: April 21, 2009
    Solutions of streptomycin were sprayed on tobacco seedlings in the seedbed to determine the effect on growth in the seedbed and in the early stages after transplanting into the field.
    Tobacco seedlings grown in the seedbed were given 1-4 sprays at intervals of a week with concentrations of 200mcg/ml streptomycin sulphate. Tobacco growth was estimated by the number of leaves, length and width of the largest leaf and the fresh and dry weight of the whole plant. It was found that when streptomycin was sprayed to tobacco seedlings a favourable effect was exhibited in the growth of the whole plant.
    Tobacco seedlings grown in the seedbed were given two sprays at intervals of a week with concentrations of 125 and 250mcg/ml of streptomycin chloride respectively and transplanted into the field. The plants showed a favourable growth in the early stages after the transplanting which appeared to be due to excellent root development.
    It was observed that tobacco plants sprayed with streptomycin formed flower buds earlier than the untreated plants.
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  • Nakato NAITO, Yoshiyuki KOJIMA
    1957 Volume 22 Issue 4-5 Pages 193-196
    Published: December 31, 1957
    Released: March 08, 2010
    1. The colonies of Gloeosporium olivarum on peptone-salts agar plate containing different concentrations of sodium 2, 4-dichlorophenoxy acetate (2, 4-D), 2, 4, 5-trichlorophenoxyacetic acid, 2-methyl-4-chlorophenoxyacetic acid, 2-chlorophenoxyacetic acid, and 2-methylphenoxyacetic acid lose in general their circular outline as growth continues, and their margin becomes wavy and irregular. On the other hand, the colonies on the same medium containing 2-methylphenol, 2-chlorophenol, 2, 4-dichlorophenol, potassium α-naphthaleneacetate, and CuSO4 resembled the controls in the regularity of their periphery.
    2. Morphological responses of Gloeosporium kaki, and Schizophyllum commune to 2, 4-D were similar to those of G. olivarum in showing irregularity of periphery, while those of Cochliobolus miyabeanus to the chemical were indistinguishable from the controls except for smaller size.
    3. These results support the view of Brown and others who stated that such an irregularity of colonies is a characteristic of the "stalingtype" growth.
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  • Hideo TAKEUCHI, Haruo IDE
    1957 Volume 22 Issue 4-5 Pages 197-200
    Published: December 31, 1957
    Released: January 12, 2010
    In the present study, the writers compared the changes of fungicidal activities of four organic mercury compounds, i.e., methylmercury iodide, ethylmercury phosphate, methoxyethyl mercury chloride, and phenylmercury acetate, after they were applied to soil. Ten ml. solution of each compound was applied 12g. soil. kept at 25°C. for 24 hours, and the fungicidal activity of the soil-organic mercury compound mixture was assayed on the plate culture of Ophiobolus sativus by the use of cup method. After this, the soil was washed with 10ml. distilled water, filtered through Toyo Filter paper NO. 2, and the fungicidal activity of the filtrate and that of soil residue were assayed by the same method. This procedure was repeated 8 to 14 times.
    1. Methylmercury iodide-soil mixture had a fungicidal activity equal to that of the methylmercury iodide solution. After repeated washing with distilled water, the fungicidal activity of the soil residue decreased, but it still maintained a certain constant level (Fig. 2). This suggests that the compound. combines with soil particles without losing the fungicidal activity.
    2. Methoxyethylmercury chloide-soil mixture showed a very low fungicidal activity. By repeatedly washing the soil with distilled water, the soil residue lost rapidly the fungicidal activity, but the filtrate maintaind a certain level of activity (Fig. 3).
    3. Ethylmercury phosphate-soil mixture had a fairly high fungicidal activity. The fungicidal activity of filtrate and soil residue, obtained by washing the soil with water, decreased gradually with the repetition of washing (Fig. 4).
    4. Phenylmercury acetate-soil mixture showed a very low fungicidal activity. The Soil residue and the filtrate, obtained by washing the soil with water, maintained a very low fungicidal activity, decreasing gradually with the repetition of washing.
    Above results suggests that the Booer's hypothesis (1944) is true with the latter three compounds, but it is not true with methylmercury iodide.
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  • Toshihiro KAJIWARA, Yoshito IWATA
    1957 Volume 22 Issue 4-5 Pages 201-203
    Published: December 31, 1957
    Released: April 21, 2009
    Sporulation process of cucumber downy mildew fungus (Pseudoperonospora cubensis) was studied, and microphotographed by use of the methods adopted by Toyoda and Suzuki (1952) for rice blast fungus.
    The diseased leaf was detached at 7.00-8.00 p.m. from the potted cucumber plants grown in the greenhouse, and its surface was washed with water to remove the existing conidiophores. The lesion was then cut off into a piece of 1×2cm. and placed in a moist cell under a microscope in a dark room, at 22-26°C. for periodical observation.
    After the leaf lesion was placed in the moist cell, conidiophores emerged through the stomata from 2 to 4 1/2 hours, and began to branch dichotomously from 6 1/2 to 9 hours. They continued to branch in the same manner until they had 3 to 16 ultimate branchlets. 20 to 50 minutes after the beginning of branching, a small hyaline projection was produced almost simultaneously at each ultimate branchlet of a conidiophore. This projection developed, to a mature conidium 50 to 70 minutes later, turning grey.
    When the conidiophore which had begun to branch was subjected to unfavorable conditions such as drying, it stopped to branch and turned to produce conidia.
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  • Yoshito IWATA
    1957 Volume 22 Issue 4-5 Pages 203
    Published: December 31, 1957
    Released: April 21, 2009
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  • Yoichi YAMAGUCHI
    1957 Volume 22 Issue 4-5 Pages 204-210
    Published: December 31, 1957
    Released: March 08, 2010
    The effects of nitrogen source, temperature and pH upon growth and spore formation of Thielaviopsis basicola in culture were studied. Three isolates from diseased tobacco roots, different in cultural characters, namely No. 1, No. 11 and No. 13, were used, throughout the experiment.
    None of the three isolates used did utilize nitrate as nitrogen source. Asparagine and amino acids tested had a better effect on the mycelial growth than ammonium salts. Formation of chlamydospores and endoconidia of the fungus was influenced greatly by the nitrogen source. For example, (NH4)2SO4 blocked endoconidial formation of No. 11 and 1-leucine blocked chlamydospore formation of No. 13. When inorganic salts were used, No. 13 produced many chlamydospores and few endoconidia, but organic ammonium salts affected the spore formation in the reverse. Among the compounds tested, d, 1-alanine, glutamic acid and aspararagine were considered to be the best nitrogen sources. CaCO3 and Na2 HPO4 increased the mycelial weight in liquid culture, but the latter had apparently antagonistic effect on the former. The growth in plate cultures was good at 18-26°C. The optimum temperature for mycelial development of No. 11 was 26°C at pH 5.5-7.0, and 22°C at pH 5.0 and 7.5. Growth rate of the mycelium decreased rapidly at 28°C., and qt 30°C and 32°C it became very slow; at 8°C the mycelium could not develop. At 37°C the fungus was unable to survive. Although pH of solid medium affected the mycelial growth less than temperature, endoconidial formation was controlled by pH as well as temperature. It was often observed that pH of liquid media changed towards the acid side at first and then towards the alkaline side, which was accompanied by an increase of mycelial weight. The variation of pH was greater in liquid potato media than in synthetic media used, and when culturing temperature was between 8-26°C, variation was increasing with the temperature.
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  • Ryutaro SAKAI
    1957 Volume 22 Issue 4-5 Pages 211-214
    Published: December 31, 1957
    Released: March 08, 2010
    The purpose of the present experiments was to make clear the effects of ultraviolet on the aerial mycelium and spore formation of Phytophthora infestans in bean meal agar. The fungus used in this study was common strain of P. infestans Race O, isolated in 1954 from naturally infected Irish Cobbler at Kotoni in Hokkaido. The source of ultraviolet radiation was a Toshiba sterilamp with a GL-15×1 lamp which gave off rays from 1850 to 5780 Å, and little rays of wave length below 3000 Å were transmitted by the petri dish glass. Plate cultures with (direct radiation) or without (indirect radiation)- covers were exposed for varying periods of time at a distance of 15 cm from the energy source. Direct radiation with rays of wave lengths 1850-5780Å, resulted in decreased growth rate for 30 seconds and lethal effects to aerial mycelium for 60 seconds. Indirect radiation, exposures for from 5 minutes to:6 hours, with rays of 1850-5780Å. had no detrimental effects on the fungus. The spore formation of the fungus appeared to be most, richest in direct radiation for 10 seconds and:Indirect radiation for 5-10 min utes, buf direct radiation produced effects like those given by much weaker indirect radiation.
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  • Yasuo KOMURO
    1957 Volume 22 Issue 4-5 Pages 220-224
    Published: December 31, 1957
    Released: April 21, 2009
    The virus isolated from mosaic plants of squash, the symptoms and host range of which were described in the previous paper, withstood 50°C for 10min., 1/500 dilution and 5 days' aging in vitro. It was inactivated in extracted sap by 55°C for 10min., by 1/500 to 1/1, 000 dilutions or by 5 to 10 days' aging at room temperature. It failed to protect cucumber and squash plants from infection by cucumber mosaic virus, showing that the virus is not allied to the cucumber mosaic virus.
    The virus was compared with the descriptions of those viruses that have been reported to be infective principally on cucurbits, and was identified to be a strain of the melon mosaic virus designated by Lindberg et al. in 1956. It may be closely related to the bottle gourd mosaic virus described by Vasudeva and Lal in India, or to the cantaloupe mosaic virus reported by Aycock, or to the watermelon mosaic virus described by Anderson in U.S.A.
    From mosaic plants of white gourd, oriental pickling melon and watermelon, a virus was recovered, being very similar with the present Virus in pathogenicity.
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  • Yoshisaburo TAKAMURA
    1957 Volume 22 Issue 4-5 Pages 225-229
    Published: December 31, 1957
    Released: April 21, 2009
    A study has been made on the TTC reduction of the mycelial homogenate of rice-blast fungus, Piricularia oryzae Cav., particulaurly on its inhibition by several fungicides. The mycelia grown on Tochinai's synthetic media containing potato decoction at 27°C for 72 hours in shaken culture, were homogenized and fractionated according to the scheme shown in fig. 1, and the supernatant obtained was poured into Thunberg tube for test. After 2 hours of incubation at 28°C, the produced TPF (triphenyl formazan) was measured by an electrophotometer (filter S 48). As a relatively marked TTC reduction of the homogenates was noted at a rate of 20g mycelia per 100ml homogeaate, this concentration was used throughout the experiments.
    A considerable portion of the activity of TTC reduction was retained in the supernatant fraction after the centrifugation of mycelial homogenates (Table 3). TTC reductivity of the homogenate was lost by heat treatment at 50°C for 10 minutes, and by addition of malonate at a concentration of 0.02M, while reduction was accelerated by adding 0.02M succinate (Tables 4 and 5). Therfore it seems to be reasonable to assume that the TTC reduction above mentioned is probably attributable to succinodehydrogenase system of the present fungus. As shown in the figures 2 and 3, TTC reduction was retarded by various fungicides, especially by those belonging to mercuric group, among which MEMC and EMP exhibited a strong inhibition at concentrations of 10-5-10-7M. The grade of inhibition decreased in the following order; PMA, MC 10-4-10-6M; PMTS, EMTS 10-4-10-5 M; copper sulfate, thiram and zineb 10-3-10-5 M; DNPTC, TCDNB 10-3-10-4M; PCNB did not inhibit at all. These results are consistent with those obtained in the author's another experiment on the vapor action of fungicides and the direct fungitoxicity to spore germination. Cysteine at concentrations of 10-2-10-4M increased the rate of TTC reduction, and reversed the inhibition by the mercuric compounds such as PMA, MC and EMP.
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  • Koji HIRATA, Kunihiko TOGASHI
    1957 Volume 22 Issue 4-5 Pages 230-236
    Published: December 31, 1957
    Released: April 21, 2009
    This paper deals with the results of inoculation experiments, in which the excised first leaves of barley seedlings were inoculated with conidia of race 1 of Erysiphe graminis hordei, the basal parts of the leaves being inserted in water or 0.01-0.015mol solutions of certain inorganic salts.
    1. When the leaves are inserted in water, the first haustorium of the mildew colony is formed more easily in the auxiliary cell than in the ordinary epidermal cell. Frequency of the initial infection of auxiliary-cell by the first haustorium may attain as high as 90 per cent of the total infections.
    2. The liability of the auxiliary-cell to initial infection seems to be not necessarily connected with movement of the stoma, nor with the thickness of the outer wall or the sunken position of the auxiliary cell.
    3. Solutions of calcium salts increased remarkably mildew susceptibility of the leaves. It is worthly to mention that the initial infections of ordinary epidernal cells increase notably in number, hence the frequency ratio of the auxiliary-cell-infection by the first haustorium falls. At higher concentrations (0.04 or 0.07mol) of calcium salts, the effect was more conspicuous.
    4. Similar effects by calcium salts were observed when conidia of a different race (IX) and of the Agropyron mildew were used as inocula.
    5. Magnesium chloride increased susceptibility, but less than calcium salts, while barium chloride decreased it. Potassium and soda salts exerted no marked influence upon susceptibility, while lithium chloride furnished with remarkable rsistance. Ammonium salts increased resistance in some instances.
    6. Mixed solutions of calcium salts with potassium or soda salts caused intermediate influence upon susceptibility. Lithium chloride has a strong antagonistic action to calcium salts.
    7. Darkening the leaves or washing them with running water showed similar, but less effects with calcium salts.
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  • Kohei TOMIYAMA
    1957 Volume 22 Issue 4-5 Pages 237-242
    Published: December 31, 1957
    Released: April 21, 2009
    1. Tissues of a potato petiole and slices of potato tuber were heated at 45°-53.5°C for five minutes, and then inoculated with Phytophthora infestans. The resistance of them to P. infestans was reduced remakably.
    2. No influence of the heat-treatment on the time required for penetration of the fungus into the host cell, nor on the growth rate of the intracellular hypae was found by microscopical observations on the cortex cells of the petioles.
    3. The necrogenous reaction of potato-plant tissue to infection by incompatible race of Phytophthora infestans was delayed remarkably by pre-infectional heat-treatment. The delay of the hypersensitive death of an infected cell was ascertained by microscopical observation on the cortex cells of the petioles.
    4. The appearance of protoplasmic strands, in the cut-surface cell of a petiole was reduced remarkably by the heat-treatment.
    5. The R.Q. of the potato tuber slice was not affected by the heat-treatment, but the respiratory rate was depressed remarkably by the same treatment. The rate of respiratory depression seems to go along with that of the reduction of resistance.
    6. Basis was found for the supposition that the metabolic activity in the cell is closely associated with the hyper-sensitive death of infected cell.
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  • Satoshi WAKIMOTO
    1957 Volume 22 Issue 4-5 Pages 243-250
    Published: December 31, 1957
    Released: April 21, 2009
    This investigation deals with protective effects of several materials against inactivation of Xanthomonas oryzae phage (OP1 phage) during desiccation.
    OP1 phage particles are mostly inactivated during any one of the following procedures: freeze-drying, vacuum drying, or drying in an ordinary desiccator under normal room temperatures, when the phage particles are suspended in distilled water. If the phage particles are suspended in a solution of protein such as gelatin or albumin, at a concentration of 10-3 gram per ml or more, about 70 per cent of the phage activity is protected in the case of freeze-drying, and 20per cent in the case of vacuum drying.
    Concentrated (10per cent) solution of gelatin hydrolysate protects the phage activity almost completely against inactivation, in the case of freeze drying; 50per cent or more, in the case of vacuum drying. When the phage particles are dried together with semi-synthetic media containing potato extract, peptone, sugar and certain inorganic salts, about half of the activity is protected in the case of freeze drying; about 35 to 40per cent in the case af vacuum drying.
    If the phage suspensions, are dried under ordinary atmospheric pressure and temperature, the phage activities decrease rapidly, even when protective materials are added (Table 1).
    Ten per cent solution of mixed amino acids is equivalent to gelatin hydrolysate, protects ca. 20per cent of the phage activity, in the case of vacuum drying (Table 8).
    Among amino acids which constitute gelatin hydrolysate, glycine, alanine and proline (two per cent solution in each case) show a certain protective effect against inactivation of the phage, in the case of vacuum drying (Table 9).
    Histidine, glutamic acid and aspartic acid (at the same concentration), protects 10per cent, 6per cent and 3per cent, respectively, at pH 7.2.
    These protective effects are retained for more then 4 days (Table 9).
    Mode of action of these proteins, protein hydrolysates and amino acids in protecting the OP1 phage against inactivation during drying procedures seems likely to be the protection of the phage particles, not only by forming protein- or peptide- monomolecular membrane, but also by somehow combining with active portions of the particles.
    Neither carbohydrates such as soluble starch, sucrose, glucose, nor inorganic salts such as CaCl2 and NaCl show protective effects. For the preservation of the phages, the most favourable method is the freeze drying of the phages with 0.001 to 0.1per cent solutions of protein, protein hydrolysate, or with semisynthetic media. Phage preparations with constant high titres are thus available, whenever required.
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  • Yoshio KUROSAKI
    1957 Volume 22 Issue 4-5 Pages 251-256
    Published: December 31, 1957
    Released: April 21, 2009
    1. Die Fleckengrößeverteilung bei der Helminthosporiose von Reispflanzen ist nicht normal, sondern eine ungewöhnliche Verteilung, die sich nach links stark verbiegt.
    2. Eint theoretische Verteilungsfunktion wurde unter Voraussetzung eingeführt, daß die Verteilung von der Widerstandsfähigkeit des Reisgewebes abhangt.
    3. Der Autor definierte die Ausbreitungsresistenz αt wie folgend:
    αt=-ΔNt/NtΔt wobei Nt das Zahl von Parasiten, die an Zeit t nach Infektion in den Wirtsgeweben wachsen, und -ΔNt das Zahl von während Δt durch die Widerstandsfähigkeit des Wirtes gehemmten Parasiten ist. 4. Aus dieser Definition kommt die Wahrscheinlichkeitsdichte der Fleckenlangeverteilung wie in folgendem Ausdruck:
    wobei x Fleckenlange ist; und wenn man die Einheit von t so wahlt, wie Wachstumsgeschwindigkeit der Flecke 1 wird, ist f(t)=αt und
    5. Als die Funktion f(x) nahm der Autor eine Exponentialfunktion; das heißt,
    6. Der durch diese Funktion gerechnete Wert stimmt mit dem ursprünglichen wohl überein; daraus geht vorher, daß die Fleckengrößeverteilung sich auf Widerstandsfähigkeit des Wirtes so eng bezieht, wie man durch die Verteilung den Ablauf der Widerstandsfähigkeit beschreiben kann.
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  • Yoshio KUROSAKI
    1957 Volume 22 Issue 4-5 Pages 257-259
    Published: December 31, 1957
    Released: April 21, 2009
    1. Die Flekenlangeverteilung der Helminthosporiose von Reispflanzen wurde mit 4 Arten des Wirtsgewebes beobachtet, die sich im Bezug auf die Widerstandsfähigkeit unterschieden.
    2. Jeder beobachteten Verteilung gab der Autor die theoretische Verteilungsfunktion, die in seiner letzten Arbeit eingeführt worden hatte.
    3. Die Verteilungsfunktion gilt jeder ursprünglichen Fleckenlängeverteilung wohl.
    4. Aus der Fleckenlängeverteilung kann man die Beziehung zwischen der Ausbreitungsresitenz des Wirtsgewebes und der Zeit nach Invasion des Erregers durch eine einfache Rechnung ziehen.
    5. Auf den Grund des so gerechneten Resistenzablaufs diskussierte der Autor von dem Unterschied der 4 artigen Wirtsgewebe und der Beschreibungsmethode für Ausbreitungsresistenz.
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  • Toru SHIMOMURA, Yonosuke NISHIKAWA, Tokuzo HIRAI
    1957 Volume 22 Issue 4-5 Pages 260-264
    Published: December 31, 1957
    Released: April 21, 2009
    Recently the writers have presented the evidence that the new antibiotics separated by the laboratory of Takeda Pharmaceutical Industries, Ltd. inhibit by 20-58per cent the TMV multiplication in detached tobacco leaf. These results have been obtained by leaf-dipping and -floating methods, presumably under the most favorable conditions. The subsequent investigations were designed to apply by leafspraying method the antibiotics which had been proved to be relatively effective in the previous screening tests.
    As test plant, detached tobacco leaf-halves were used. Selected leaves of uniform size were inoculated to the lower side with TMV, and cut into halves. One of the halves was sprayed with an antibiotic solution, and another half was left for check. These halves were maintained in a Petri dish, dipping the cut edge in water, as illustrated in figure 1. The assay of TMV produced in leaf tissues was carried out by the chemical analysis of the virus protein, the procedure of which is shown in figure 2, in parallel with the local lesion method using bean leaves. The measured account of virus protein in the leaf showed a moderate correlation with the number of local lesions produced on bean leaves (Figure 3).
    From the results of the virus protein analysis, 3 new antibiotics out of 18 tested were found to exhibit 20 per cent or more inhibition to virus multiplication, while higher figures of inhibition was obtained by the local lesion assay (Table 1). This finding raises the serious problem whether the local lesion method represents a real value of virus activity. In order to see the effect of antibiotics upon symptom expression, potted tomato seedlings inoculated with TMV, were sprayed with antibiotics. As represented in table 2, almost no visible effect of the antibiotics upon symptom exhibition was noted, nevertheless yet 20per cent or more virus inhibition was confirmed by the chemical analysis of the virus protein produced within the plant.
    The authors' sincerely thanks are due to Dr. R.A. Gray, who kindly supplied noformicin to our laboratory.
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  • Fukuji NONAKA
    1957 Volume 22 Issue 4-5 Pages 265-267
    Published: December 31, 1957
    Released: April 21, 2009
    The influences of neck and node blast caused by Piricularia oryzae and of sheath spot caused by Corticium sasakii on the severity of stem rot (Leptosphaeria salvinii) were studied.
    The severity of stem rot increases when the same stem is affected with node blast, while the resistance to the stem rot increases when it is heavily affected with neck blast.
    The severity of stem rot does not increase by the light damage of sheath spot, but decidedly increases by the heavy.
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  • Masao GOTO, Norio OKABE
    1957 Volume 22 Issue 4-5 Pages 268-273
    Published: December 31, 1957
    Released: April 21, 2009
    1. Researches were made on heat inactivation of flagellar and somatic antigens of Erwinia carotovora against agglutination reaction, with the results mentioned below.
    2. Flagellar antigens of 12 serotypes, heated in distilled water at 50° to 80°C for 10min., and agglutinated by their homologous antisera, proved to be inactivated by heating at various degrees of temperatures from 58° to 78°C according to serotypes, these inactivation temperatures being repetitious within a limit of ±1°C.
    3. Differences of inactivation temperatures corresponding to antigenic components in a flagellar antigen were demonstrated to exist in same serotypes.
    4. In serotype K, the flagellar component a was inactivated at 75°C in the existence of k and c components, although the former was inactivated at 63°C in the case of a alone. This difference of the inactivation temperatures appeared to owe to a mutual effect between the flagellar components of serotype K on the thermal inactivation against agglutination reactions.
    5. Somatic antigens of a non-flagellated strain, inactivated by heating at 55°C for ten minutes, lost their agglutinativity.
    6. In most serotypes, isolates agglutinated with O-antiserum prepared by injections of bacteria heated at 100°C for one hour were lesser in number than those agglutinated with OH serum. But, in serotype D, this relation was reverse.
    These were responses due to the layer construction of somatic antigen components
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    1957 Volume 22 Issue 4-5 Pages 274-275
    Published: December 31, 1957
    Released: April 21, 2009
    The faculty to produce fusaric acid in culture which is toxic to plant living cell was investigated by using the 25 strains belonging to 6 sgecies of the genus Fusarium. In F. oxysporum and F. maniliforme all the forma specialis were positive, but the other four Fusaria employed in the present experiment were negative.
    It might give an interesting problem in the study of pathological wilt-mechanism in pinat, that all the Fusarium belonging to oxysporum and moniliforme, have the faculty of fusaric acid production and then cause a systemic fusariose as wilting or damping off of host plant Moreover, application of investigating the faculty to produce such specific metabolite as fusaric acid in culture will be help in studying species relationship in Fusaria.
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  • Masao GOTO
    1957 Volume 22 Issue 4-5 Pages 276-279
    Published: December 31, 1957
    Released: April 21, 2009
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