Japanese Journal of Phytopathology
Online ISSN : 1882-0484
Print ISSN : 0031-9473
ISSN-L : 0031-9473
Volume 18 , Issue 1-2
Showing 1-14 articles out of 14 articles from the selected issue
  • Saburo KOBA
    1953 Volume 18 Issue 1-2 Pages 1-4
    Published: December 30, 1953
    Released: February 19, 2009
    JOURNALS FREE ACCESS
    Cotton seedlings are highly susceptible to damping off (Fusarium spp.) at the beginning of the development of lateral roots.
    Cotton seedlings affected at this stage, 8 to 15 days old (H-K in Fig. 1) are hardly able to recover and killed easily.
    At these critical stages, especially 10 to 12 days old (I and J in Fig. 1) cotton seedlings show little or no carbon assimilation, maximum respiration rate, minimum transpiration rate, and exhaustion of stored-up food.
    The infection by damping off fungi often causes over-increase of respiration and over-decrease of transpiration in cotton seedlings.
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  • Shigeyasu AKAI, Hiroshi YASUMORI
    1953 Volume 18 Issue 1-2 Pages 5-8
    Published: December 30, 1953
    Released: February 19, 2009
    JOURNALS FREE ACCESS
    1. The present paper deals with the results of the investigations on the influence of azo-pigment congo red, chrysoidin, Bismark brown, and methylorange to Cochliobolus miyabeanus.
    2. Congo red and chrysoidin possess the obvious fungistatic effect on the mycelial growth of the fungus showing definite retardation of the lag phase (primary stage) of the mycelial growth, when the fungi were cultivated in the 7.5×10-4∼5×10-4M solution. Congo red is more effective than chrysoidin. Methylorange and Bismark brown, however, have no retarding effect on the mycelial growth.
    3. Chrysoidin (basic dye) showed the more marked suppression of the fungus growth in the alkaline side of the nutrient solution. Methylorange (acid dye), however, did not show the distinct effect on the growth of the fungus in the acid side of the solution.
    4. Congored seemed to have no effect on the germination of the fungous conidia. In the concentrated solution, however, all germ-tubes swell and change into spore-like vesicles immediately after their germination. No germination of spores took place in distilled water, when they were suspended for one hour in 10-3M solution of chrysoidin.
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  • Hiromu YOSHII
    1953 Volume 18 Issue 1-2 Pages 9-13
    Published: December 30, 1953
    Released: February 19, 2009
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    In order to research the influence of cephalothecin upon the nutritional absorption of NH4-N by the blast fungus, cultural experiments were carried out by using the modified Tochinai and Nakano's synthetic nutrient solution with addition of Biotin or decoction of rice-culm. Cephalothecin was tested at dilutions of 1:5∼160. The amount of ammonium absorbed during the development of the fungus in the culture solution was determined by the ordinary distillation method every other day. The growth of the fungus and its absorption of NH4 was more or less inhibited by supply of cephalothecin (table 3). The dry weight of the mycelial mat, and amount of ammonium absorbed in cultures supplied with ammonium salt, were larger than in cultures than in cultures without any ammonium salt. The differences are indicated by symbols of H and N respectively.
    After 4 and 6 days' incubation, it was shown that N:H was far larger in cultured containing cephalothecin at strengths of 1:2∼20 than either in 1:40∼160 or in the check. Even after 10 days, it was rather larger in 1:5∼10 solution than in others. The relative absorption value (N:H) shows the amount of the ammonium consumed by the fungus to increase 1mg of the mycelium in dry weight. Accordingly, for consumption of 1mg of ammonium, the increase in dry weight of the mycelium should be far less in 1:5∼20 solution of cephalothecin than either in 1:40∼160 or in the standard solution.
    On the other hand, the analyses of the leaf-blades and sheathes of the rice plants showed that the contents of the nitrogenous compounds in the nontreated plants, and that especially the contents of NH4-N decrease considerably in the former. Thus, the phases of N:H suggests certain connection between the fungu's absorption of NH4-N under the influence of cephalothecin and the resistance to blast disease of the rice plant treated with cephalothecin.
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  • Hisayoshi NOSE
    1953 Volume 18 Issue 1-2 Pages 14-16
    Published: December 30, 1953
    Released: February 19, 2009
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    The report states about the results of the experiments and observations on the saprophytic propagation of Hypochnus centrifugus in the soil.
    (1) Hypochnus centrifugus grows and forms sclerotia on the agar culture media prepared with coarse powder of rice-straws, pine needles, sweet-potato vines and leaves, grass weeds, Thuja dolabrata, barley straws and soja bean plants. When the soil is mixed with these materials, the fungus develops and forms the sclerotia; in the case of an insufficient quantity of mixing materials it forms mycelia, but comes to no formation of sclerotium, leaving the mycelia blasted afterwards.
    In this cultivation experiment, when we make steam-sterilization of the soil mixed with organic materials, the fungus is observed to be rather poor-developed, in comparison with the case non-sterilization. In the soil not mixed with organic materials we also find the same tendency of the mycelia in growth.
    (2) From the out door observation, it is found that Hypochuns centrifugus, in the field without host-crops, also saprogenerates and develops itself to form sclerotia on the blighted crops and weeds, no host plants, such as the fallen blades and ears, roots of straws, the dead stump of Oxalis martiana and others. This saprophytic propagation is often found in the soil where Hypochnus centrifugus exists, remarkably in the rainy season.
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  • Hiromu YOSHII
    1953 Volume 18 Issue 1-2 Pages 17-21
    Published: December 30, 1953
    Released: February 19, 2009
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    In the studies on the influence of cephalothecin upon the secretion of carbohydrases and the absorption of NH4-N by the blast fungus, it was pointed out by the writer that S:N, i. e., Relative Secretion Value (Yoshii 1953), and N:H, i. e., Reiative Absorption Value (Yoshii 1953), of the culture on media supplied with cephalothecin were far larger that of check. These figures show that the increase in dry weight of the mycelium per unit amount of carbohydrates and NH4-N consumed in cultures supplied with cephalothecin is much less than that of check.
    The poorer the development of the fungus in the tissue of the host is, the smaller the spot on the plant is. The spread of the fungus in the host tissue hasa certain connection with the resistance of the plant. In view of this, the sheath inoculation method (Sakamoto 1951) was applied to the earneck tissue presoaked with cephalothecin in order to determine if cephalothecin impedes the invasion processes of the blast fungus in the cells of rice plant.
    The results of the observations showed that the inhibitory effects of cephalothecin on the development of the fungus were also remarkably recognized in the cells of the tissues treated with cephalothecin. So it may safely be concluded that the resistance of the treated rice plant to the blast disease is chiefly due to cephalothecin sucked in the tissue.
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  • Michio GONDO
    1953 Volume 18 Issue 1-2 Pages 22-24
    Published: December 30, 1953
    Released: February 19, 2009
    JOURNALS FREE ACCESS
    The effects of α-naphthalen acetic acid and 2-4-D on the infection of tobacco by ordinary mosaic virus were studied. Detached leaves of Nicotiana glutinosa were inoculated and placed on Curt Leben's agar plates supplied with a plant hormone. The results indicated that the numbers of necrotic spots on the half leaves treated with both plant hormones were less than on untreated halves.
    The numbers of necrotic spots on the leaves inoculated with the mixture of plant hormone solutions and virus juice differed from the ones inoculated with virus juice only.
    These plant hormones presumably effected not on the activity of virus but on the susceptibility of the host plant.
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  • Mutsuo TERUI
    1953 Volume 18 Issue 1-2 Pages 25-27
    Published: December 30, 1953
    Released: February 19, 2009
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    This paper is written the experimental results on the cultural characteristics of the violet and white root fungi, Helicobasidium Mompa TANAKA and Rosellinia necatrix (HARTIG) BERLÉSE, on apple trees.
    1. The growth of Helicobasidium Mompa is very slower than that of Rosellinia necatrix, especially in the growth of the aerial and superficial hyphae. However, it is conjectured that the submerged mycelia of Helicobasidium Mompa is able to develop deeper and more luxuriant than that of Rosellinia necatrix in the nutritional media. The dry weight of mycelial felts may explain a part of its reason.
    2. In both Helicobasidium Mompa and Rosellinia necatrix, the development of its mycelia in the dark is more vigorous than in the daylight and its difference between them seems to be more remarkable in the mycelia of Rosellinia necatrix.
    3. The dry weight of mycelial felts of Rosellinia necatrix cultured in six weeks becomes lighter than that of culturd in four weeks. This supposed to be the result of autolysis of the fungus.
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  • H. ASUYAMA, S. YAMANAKA
    1953 Volume 18 Issue 1-2 Pages 28-32
    Published: December 30, 1953
    Released: February 19, 2009
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    Since 1947, stem rot of peanut caused by a Diplodia has been found in some fields in the Kanto district. The pathogen produces pycnia on the affected stems and petioles. Immature pycniospores are hyaline and 1-celled, while mature spores are dark and 1-2 celled, measuring 19-30 ×10-17μ in size. The perfect stage has not been found on the plants nor in culture. The organism grows well on media of various kinds. The cardinal temperatures are 12-30-31∼40°C. Optimum pH for growth is 4.0-6.1. The cultures isolated from peanut could kill not only peanut but beans. They caused rots of melon, apple, Satsuma orange, corn-ear, and cotton-boll. On adzuki bean (Phaseolus angularis Wight), soybean and sweet potato, they simply produced necrotic lesions.
    Morphologically and physiologically the organism resembles closely with each of Diplodia gossypina, D. tubericola, D. natalensis, and D. frumenti, and is believed to be a strain of the collective species including these allied species. It remains the need for further investigation for identification, but the name of D. natalensis was tentatively adopted following Jacoway(6) and Ramsey(11).
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  • K. HIROTA, M. SUMI, S. YOSHIMURA, G. KUWADA
    1953 Volume 18 Issue 1-2 Pages 33-36
    Published: December 30, 1953
    Released: February 19, 2009
    JOURNALS FREE ACCESS
    1. We tested on the relation between wax content in sand to the penetrating power of wetting agents by using columns of sand. The results were as follows:
    a) When sand has no paraffin wax, penetrating power of wetting agent solution decrease as larger amount of wetting agent are added, and show alway lower ability than that of water.
    b) When sand is contained 0.124∼0.37% of paraffin wax, the penetrating power reach a maximum at some intermediate concentration (0.005∼0.05%) of wetting agents.
    c) When sand is contained more than 0, 45% of paraffin wax, solution which contained lower conecntration than 1 percent of wetting agents can not penetrate into the sand and the penetrating power represents as more than 1 percent of wetting agent is added.
    2. The toxicity of phenyi mercuric acetate for Hypochnus centrifugus and Ophiobolus Miyabeanus show a maximum when 0.005∼0.05% of wetting agents is added. This fact is seemed to concern the sand test b.
    3. The injury of phenyl mercuric acetate solution for germination of wheat seed don't appear when less than 0.5% of wetting agent is added, whereas it show injury when more larger amount is added. This fact seemed to concern the sand test c.
    When the rice seed is treated with same solution, injury is reached a maximum by the addition of 0.005∼0.05% of the wetting agent.
    Those phenomenons given above, seem impossible interpret the results in term of surface tention and contact angle. It is seemed by the effect of differencial abilities at critical micell concentration of wetting agent solutions for materials that containing varily lips.
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  • Yasuyuki MIYAHARA
    1953 Volume 18 Issue 1-2 Pages 37-40
    Published: December 30, 1953
    Released: February 19, 2009
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    1. In this paper, the results of experiments on the relations between chemical structures as well as capillary activities and fungicidal (fungistatic) actions upon the conidia of Ophiobolus Miyabeanus Ito et krib. of monobasic fatty acid soaps of carbon number 4∼18 and other capillary active substances were described. For evaluating the fungicidal action the conidia were submerger in the solution of fungicide for 4 hours at temperature 28°C, then submitted for germination after washing with water.
    2. The fungicidal action of the monobasic saturated fatty acid potassium soaps increased gradually with increasing carbon numbers and reached maximum at the capric (C10) and lauric (C12) acid soaps, then diminished again. There were some correlations between the fungicidal actions and the capillary activities of these soaps. The solutions of cepric and lauric acid potassium soap showed some difference in their dissociation degrees, while their fungicidal actions were equally powerful in the same molecular concentration, viz. about 90% of conidia were fungistatic with 0.01M solutions.
    3. The potassium soaps of monobasic unsaturated oleic, linolic and linoleic acids with carbon numbers 18 showed smaller fungicidal power than those of the saturated acids, and any correlation of fungicidal power with capilary activities was hard to find. The increase of the unsaturated double bonds in the molecule of the soaps having the same carbon numbers (C18) promoted the fungicidal power slightly.
    4. No difference in the fungicidal actions was found between the sodium and potassium soaps of monobasic saturated fatty acids.
    5. Naphthenic and abietic acid soaps, while showing similar physical properties with fatty acid soaps, had low fungicidal power.
    6. Detergents such as Igepon T, Nekal BX and sodium salt of sulfate of ricinoleic acid showed very weak fungicidal power, though their capillary activities were very strong.
    7. The cation active soap containing cetyl-dimethyl-benzyl-ammonium chloride had considerable capillary activity and also strong fungicidal action in concentration as low as 0.004%.
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  • Hiroshi NAITO
    1953 Volume 18 Issue 1-2 Pages 41-45
    Published: December 30, 1953
    Released: February 19, 2009
    JOURNALS FREE ACCESS
    1. 29 strains of mold were isolated from samples of stored rice grain, of which moisture content had been contro led in several grades. Of the molds Pencillium and Aspergillus were most prevalent (table 2).
    2. The most vigorous development of molds was observed at 20°C during incubation and poor at 10°C and 30°C.
    3. The largest number of strains were isolated from grains with 18% moisture, the next was from grains of 20% and 16% moisture.
    4. Osmotic pressure of spore of the isolated molds exists between 19.6 and 134.8 atmospheric pressure, being the maximum value 6.9 times of the minimum value.
    5. It was observed that osmotic pressure of the molds isolated from rice grains lowest moisture content gave the highest value. According as moisture of rice increased, osmotic pressure of the associated molds decreased. So the strain of mold grown on the rice is mainly decided by the actual moisture content of the rice.
    6. The osmotic pressure of the rice grain determined on embryo and aleurone layer came to be lower in inverse proportion to the rice moisture content.
    7. It seems necessary for molds to grow on the rice grain that their osmotic pressure should be more than about 5 times higher than that of rice. The osomtic pressure of molds does not reach to 5 times of that of rice with 14.5% moisture on which, the molds can scarcely grow.
    8. As the conclusion, it is necessary to dry rice grain to a moisture content below 14.5%, in order to prevent mold growth.
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  • 1953 Volume 18 Issue 1-2 Pages 58-77
    Published: December 30, 1953
    Released: February 19, 2009
    JOURNALS FREE ACCESS
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  • 1953 Volume 18 Issue 1-2 Pages 77-86
    Published: December 30, 1953
    Released: February 19, 2009
    JOURNALS FREE ACCESS
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  • 1953 Volume 18 Issue 1-2 Pages 86-96
    Published: December 30, 1953
    Released: February 19, 2009
    JOURNALS FREE ACCESS
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