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Volume 30 (1965)
- Issue 5 Pages 239-
- Issue 4 Pages 181-
- Issue 3 Pages 115-
- Issue 2 Pages 69-
- Issue 1 Pages 1-
Volume 30, Issue 4
Displaying 1-9 of 9 articles from this issue
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V. Several species of Pythium causing root rot of strawberryMinoru TAKAHASHI, Yasuo KAWASE1965 Volume 30 Issue 4 Pages 181-185
Published: 1965
Released on J-STAGE: April 03, 2009
JOURNAL FREE ACCESSStrawberry root-rot is caused by several species of Pythium. Considerable number of works has been published concerning the disease but the identification of the causal fungi was entirely neglected or over-looked. This work, therefore, seeks to know the identities of the causal organisms.
Taxonomic studies revealed that there are 3 species aside from an undescribed species of Pythium that are pathogenic to strawberry. The 3 known species are Pythium oedochilum Drech., P. debaryanum Hesse, and P. mamillatum Meurs. A new species, Pythium fragariae was described as follows: Hyphae are coenocytic, irregularly branched, 6-8μ in width, sparingly septate with age. Sporangia are abundant on corn-meal agar, terminal and intercalary, spherical to oval, 9.9-35.5μ in diameter, average 21.4μ; germinate directly or by formation of vesicle with a short tube; 10-15 zoospores are in a vesicle. Oogonia are abundant but fewer and smaller than sporangia, terminal and intercalary, spherical to sub-spherical, smooth, very rarely with a single spine, 8.9-23.7μ in diameter, average 19.7μ. Oospores are spherical and smooth, completely filling the oogonia though very few are not, 7.5-22.5μ in diameter, average 17.0μ, thick-walled when mature. Antheridia are stalked or intercalary, rarely diclinous, hypogynal, commonly one and very seldom 2-3 to an oogonium.
Pythium oedochilum and P. debaryanum were isolated from diseased roots of strawberry collected from Ikeda City, Osaka prefecture in June, 1960, and P. fragariae was isolated in May, 1960, in Yao City of the same prefecture. Pythium mamillatum was isolated in April, 1962 at Shizuoka Agricultural Experiment Station and also identified as the cause of strawberry root decay in Kunouzan, Shizuoka prefecture.View full abstractDownload PDF (3378K) -
VI. Some species of Pythium causing rhizome rot of Hindu lotusMinoru TAKAHASHI, Akira OHUCHI, Romeo V. ALICBUSAN1965 Volume 30 Issue 4 Pages 186-191
Published: 1965
Released on J-STAGE: April 03, 2009
JOURNAL FREE ACCESSThe rhizome rot of Hindu lotus has been reported from different parts of Japan, such as Osaka, Tokushima, Aichi and Kagawa prefectures. Several species of Pythium and Fusarium were isolated from diseased lotus rhizome and considered as the causal organisms.
Pythium species were isolated selectivery by using corn-meal agar containing 50ppm streptomycin.
Pythium nelumbium n. sp. was identified as a new species besides P. spinosum Sawada, and P. ostracodes Drech. Sporangia of P. nelumbium are filamentous or composed of inflated elements and produce both zoospores and conidia. Oogonia are smooth, spherical and 20.7-31.1μ in diameter. Oospores filling the oogonium. Numerous antheridia, 8-15, are attached to an oogonium and either diclinous or androgynous.
The fungus was isolated from diseased lotus rhizome collected from Kadoma City, Osaka.View full abstractDownload PDF (2810K) -
Hiroyasu TANAKA1965 Volume 30 Issue 4 Pages 192-196
Published: 1965
Released on J-STAGE: February 19, 2009
JOURNAL FREE ACCESS1. The present paper deals with the result of the investigations on the relation between the different kinds of culture media and the activity of some carbohydrases, i.e., α-amylase, β-amylase, invertase, and maltase, produced by Cochliobolus miyabeanus. The estimation was made using both intra- and extra-cellular preparations.
2. As to α-amylase and β-amylase, extra-cellular activity is greater than intra-cellular activity. On the contrary, greater activity of intra- than extra-cellular invertase was detected.
3. All the enzymes tested seemed to be the adaptive enzymes because their production markedly increased when the corresponding carbohydrates were added to the media.
4. All of the four carbohydrases were produced more abundantly in the maltose medium than in the other media used.
5. The activity of these enzymes is not always parallel with the growth amount of mycelial mats and the change in pH-value of the culture media.View full abstractDownload PDF (574K) -
Hiroshi EGAWA, Shinichiro TABATA, Teruhisa NOGUCHI1965 Volume 30 Issue 4 Pages 197-202
Published: 1965
Released on J-STAGE: February 19, 2009
JOURNAL FREE ACCESSIn this paper the mechanism of increment of chlorophyll content in leaves of rice plants was discussed, when sprayed with 2, 4-dichloro-6-(orthochloroanilino)-1, 3, 5-s-triazine (Triazine, Dyrene). Rice plants were cultivated in nutrient solutions deficient in N, Mg and both of them respectively. After 5 days they were transferred to the complete nutrient solution, and then sprayed with Triazine. The chlorophyll content was measured 2 days after spraying. The chlorophyll content in the leaves sprayed with Triazine increased several folds irrelevant to the prior nutritional treatment.
After spraying of Triazine, rice plants were continued to cultivate 2 days in the respective nutrient deficient solution and then transferred to the complete nutrient solution. After 2 days the chlorophlyl content of these leaves were measured. No effect of Triazine spraying was recognized in these cases.
As the effect of Triazine spraying on the chlorophyll content seemed to diminish in a few days, and as Triazine might be decomposed and utilized as a nitrogen source, the effects of spraying urea and ammonium sulfate on the chlorophyll content were compared to that of Triazine. The result indicated that the effect of Triazine was nearly equal to that of urea and larger than that of ammonium sulfate in terms of chlorophyll content.
The rate of chlorophyll decomposition was compared between the Triazine-sprayed and non-sprayed plants raised in complete nutrient solution.
When the plants were transferred to deionized water after the spraying, the chlorophyll content increased about 8% in the Triazine-sprayed leaves 2 days after the spraying. The rate of decomposition of chlorophyll, however, seemed to be the same between Triazine sprayed and control leaves, at least for 8 days.View full abstractDownload PDF (746K) -
Ikuo SUMINA1965 Volume 30 Issue 4 Pages 203-208
Published: 1965
Released on J-STAGE: February 19, 2009
JOURNAL FREE ACCESSIn this paper the fungicidal actions of zinc dithiocarbazate and its decomposed products, such as hydrazinium dithiocarbazate, N, N'-diaminothiurammonosulfide, thiocarbohydrazide, 2, 5-dimercapto-1, 3, 4-thiodiazole and hydrazine, on the anthracnose of cucumber were studied. Zineb, zinc sulfide, zinc sulfate and zinc oxide were used as a check.
Zinc dithiocarbazate was much effective to control the occurrence of the anthracnose of cucumber, its protective effect was similar to that of zineb. However, the fungitoxicity of zinc dithiocarbazate in the slide germination test against Colletotrichum lagenarium was a quarter that of zineb. The contradiction between the protective effect on the anthracnose and the fungitoxicity against C. lagenarium would be illustrated from the fact that hydrazinium dithiocarbazate, a decomposed product of zinc dithiocarbazate, was more fungitoxic than zinc dithiocarbazate.
The fungicidal action of zinc dithiocarbazate may be similar to that of hydrazinium dithiocarbazate and 2, 5-dimercapto-1, 3, 4-thiodiazole, but not similar to that of the other decomposed products and zineb, considering the slopes of the dosage response curves. From the result of the fungitoxicity test, when added the juices of the cucumber leaves to the solution of hydrazinium dithiocarbazate, it was assumed that thiocarbohydrazide and hydrazine would be decomposed products of hydrazinium dithiocarbazate.
Hydrazinium dithiocarbazate, thiocarbohydrazide and N, N'-diaminothiurammonosulfide were more effective than the other decomposed products to control the occurrence of the anthracnose of cucumber, and their protective effects were similar to that of zinc dithiocarbazate.
Summarizing above-mentioned results, it seems to assume that zinc dithiocarbazate will be decomposed as follows and the fungitoxicity may increase resulting from the decomposition.
Zinc dithiocarbazate-→hydrazinium dithiocarbazate-
-→thiocarbohydrazide, 2, 5-dimercapto-1, 3, 4-thiodiazole
-→N, N'-diaminothiurammonosulfide, hydrazineView full abstractDownload PDF (845K) -
Daiki MURAYAMA, Makoto KOJIMA1965 Volume 30 Issue 4 Pages 209-215
Published: 1965
Released on J-STAGE: February 19, 2009
JOURNAL FREE ACCESSThis paper reports information on mechanical inoculation and properties of potato leaf roll virus.
When the extracts of the diseased potato and Physalis floridana and viruliferous Myzus persicae were injected into virus-free M. persicae by the micro-injection technique, the aphids were capable of transmitting the virus to healthy P. floridana. Aulacorthum matsumuraeanum injected with the juices obtained from affected plants or viruliferous aphids, was also found to be capable of transmitting the virus. When the juices of affected P. floridana were stored at about 2°C, the virus showed its activity for 5 days. The juice frozen at -20°C for 24 hours retained its infectivity. Infectivity was found also in affected P. floridana kept at -20°C for one month. When the juices diluted to 1:1, 000 with phosphate buffer solution were injected into virus-free M. persicae, few aphids became infective. The thermal inactivation point of this virus appeared to lie between 70° and 80°C.View full abstractDownload PDF (795K) -
Daiki MURAYAMA, Tatsuo YOKOYAMA1965 Volume 30 Issue 4 Pages 216-218_1
Published: 1965
Released on J-STAGE: April 03, 2009
JOURNAL FREE ACCESSUsing the Ouchterlony gel diffusion technique, precipitation zones appearing in agar plates having circular reservoirs filled with ultraviolet-irradiated barley stripe mosaic virus (BSMV) and its homologous antiserum were examined.
With the virus exposed to ultraviolet radiation for 1 hour, no change was recognized in the antigenicity either in flocculation test or in gel diffusion test. Two hours of exposure caused a little decrease, and 3 hours of exposure caused more decrease in the antigenicity. After 6 hours of irradiation, a slight reaction was observed in flocculation test, but no visible precipitation zone could be detected in the gel diffusion test.
The antigenicity was lost after 7 hours of irradiation. The position of the precipitation zones appeared nearer to the midpoint between the antigen and antiserum reservoirs when BSMV was exposed to radiation for 2 to 5 hours. When the dose of irradiation was increased up to 5 hours, the position of the precipitation zones shifted further away from the antigen reservoir, and the curvature of the precipitation zones became smaller than in the case of untreated virus suspensions.
It was after 2 hours of irradiation that the clearest zones were usually observed, although 3 hours of treatment also resulted in clear zones. Virus preparations irradiated for 6 hours showed no visible zone, despite positive reaction in flocculation test.
It was supposed that the formation of precipitation zones were strongly enhanced by the ultraviolet irradiation of the virus, because the virus particles were cut into fragments by irradiation so that their diffusion in the agar gel became faster than in the untreated virus.View full abstractDownload PDF (490K) -
IV. The activity of antagonists to Rhizoctonia solani KühnHirosuke OGURA, Shigeyasu AKAI1965 Volume 30 Issue 4 Pages 219-224
Published: 1965
Released on J-STAGE: February 19, 2009
JOURNAL FREE ACCESSIn the present paper antagonistic activities of some soil-borne fungi were discussed in relation to the competitive existence of Rhizoctonia solani in soil.
Among 41 antagonistic fungi Coniothecium sp., Pachybasium sp., and Trichoderma spp. were selected as representative antagonists. The antagonistic activities of these fungi against Rhizoctonia solani on agar media decreased in the descending order of Trichoderma, Pachybasium, and Coniothecium, and the activity was weakened on the media containing less nutrients. Antagonistic activity of the culture filtrate of these fungi was almost lost by passing through a soil column.
In sterilized soil these antagonists inhibited the mycelial growth of Rhizoctonia solani when they were added in excess, five times the amount of the latter. In unsterilized soil, however, they did not show any antagonistic function under the same condition, excepting one strain of Trichoderma spp. Antagonists in soil remarkably inhibited the mycelial growth of Rhizoctonia, only when food base such as plant debris was added to the soil.
Quantitative ratio of both the pathogen and antagonists on the root surface or rhizoplane reflected on the disease occurrence and the damping-off seems to be prevented if antagonists existed more in amount than Rhizoctonia.
These results suggest that contacting chance of pathogen to the antagonists, relative amount of their mycelia, and their capabilities of utilizing organic materials in soil are the factors relevant to the prevention of seedling damping-off by means of antagonists.View full abstractDownload PDF (806K) -
Sakae TOYODA, Ikuo KIMURA, Naoji SUZUKI1965 Volume 30 Issue 4 Pages 225-230_1
Published: 1965
Released on J-STAGE: April 03, 2009
JOURNAL FREE ACCESSThe electron micrograph of rice dwarf virus (RDV) given by Fukushi, Shikata, and Kimura1) shows that RDV particles are enveloped with a membranaceous material. A fraction containing similar RDV particles was obtained from infected rice leaves by treating the expressed sap with 10 to 20per cent chloroform and the same differential cenrifugation procedure as adopted by Fukushi et al1). RDV in this fraction was so firmly adsorbed by DEAE-cellulose column that it could not be eluted with increasing concentration of NaCl from 0 to 1.0M, but was eluted only with 0.5M NaOH, suggesting that the virus particles were covered with some strongly acidic substance, possibly the enveloping material. This material was easily removed by treating the fraction with phospholipase of snake venom or pancreatin. After this treatment, RDV was eluted from DEAE-cellulose column with 0.2 to 0.25M NaCl. RDV in the effluent showed typical morphological characteristics, an icosahedron with hollow capsomeres, when examined under electron microscope. Electrophoretic and sedimentation patterns of the effluent showed that the preparation consisted of homogeneous RDV particles. The purified RDV retained infectivity to rice plants when assayed through the insect vector, Nephotettix cincticeps Uhler.View full abstractDownload PDF (3590K)
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