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Volume 11 (1941 - 194･･･
- Issue 4 Pages 159-
- Issue 3 Pages 101-
- Issue 2 Pages 57-
- Issue 1 Pages 1-
Volume 11, Issue 2
Displaying 1-6 of 6 articles from this issue
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Kikuji WATANABE1941 Volume 11 Issue 2 Pages 57-65
Published: 1941
Released on J-STAGE: April 03, 2009
JOURNAL FREE ACCESS1. The leaf blotch of sesame (Sesamum indicum DC.) caused by Helmin-thosporium sesamum SACC. affects seedlings, leaves, petioles, stems and pods.
2. Conidiophores of the fungus are darkish olive, measuring 105.0-337.5μ (average 194.0μ) in length by 5.0-10.0μ (average 7.11μ) in width, being provided with 2-9 (average 4.30) septa. Conidia are darkish brown, curved to one side or rarely straight, 27.5-267.5μ (average 102.9μ) by 5.0-17.5 (average 15.03μ), with 3-20 (average 8.77) septa.
3. The causal fungus grows readily on various culture media. The inoculation experiments proved the pathogenicity of the present oraganism on sesame plants. The presence of any wound on the plant is not always necessary for its infection.
4. The optimum temperature for growth of the fungus lies between 27 and 30°C, the maximum and minimum being about 37° and below 12°C respectively. Incubating at 54° for 5 minutes, the conidia in suspension were completely killed.
5. The size, shape and number of septa of conidia varies with temperatures during culture. The conidia measured in average 100.20 and 88.70μ in length, and 10.66 and 10.46μ in width at 23° and 37°C respectively.
6. The fungus was able to grow in solutions presenting pH value of 4.0 to 7.0, while it seemed to be most favoured in pH 6.2. It was noted that pH value of the liquid media inoculated with this fungus changed gradually towards 7.
7. The pathogenes are often carried in the seeds. For disinfection of such contaminated seeds, hot water treatment has been proved to be effective.View full abstractDownload PDF (3101K) -
Ecological Studies on Important Fungi pathogenic to the Crops in the Far East. ITakewo HEMMI, Zyunzo AOYAGI1941 Volume 11 Issue 2 Pages 66-80
Published: 1941
Released on J-STAGE: April 03, 2009
JOURNAL FREE ACCESS1. The disease of rice-seedlings known under the name of “Bakanaebyo” is one of the most important pests of this main crop in Nippon. In all probability the disease in question exists in all parts of the Far East, where the rice plants are cultivated.
2. According to the previous investigations, the spread of the disease is clearly in close relations with the environmental conditions before and after the flowering period of the host plant, those greatly influencing the germination of conidia of its causal fungus.
3. In the present paper the results of the writers' investigations on the relation of temp rature, humidity, sunlight and the filtrates of cultures of various fungi to germination of the macroconidia of the causal fungus, Gibberella Fujikuroi, were reported.
4. Repeated experiments showed that the optimum temperature for germination of the macroconidia seems to lie at 28°-30°C. The highest limit of temperature for germination of the macroconidia was presumed to lie at a temperature slightly higher than 44°C, the lowest limit for the same being at a temperature lower than 8°C.
5. In order to decide the effect of air-humidity upon the germinabilify of macroconidia of the causal fungus, small drops of suspension were placed on clean slide glasses and dried at 28°C. Those slides were kept on supports in special dishes, in which the air-humidity had been controlled. Those dried macroconidia on slides kept in a saturated atmosphere could germinate fairly well, averaging 45.5% at 28°C.
6. The macroconidia on slides kept at 97.5% relative humidity germinated slightly at 28°C, but not at 24°C under experimental conditions. Microscopical examination demonstrated that the formation of a thin film of water surrounding the conidia is necessary for their germination.
7. The percentage of germination and also the length of germ-tubes were greater in the absence of light than in the presence of light.
8. The filtrate of cultures of the causal fungus on potato-decoction showed a tendency to accelerate slightly the germination of the same fungus, but those of Ophiobolus Miyabcanus and Piricularia Oryzae accelerating it more clearly than that of the former. The ability of acceleration seemed to diminish by prolongation of cultural period.
9. In the experimental conditions, the ability of acceleration in the filtrates was able to resist highly to heating, but the filtrates passed through a porous filter showed a tendency to check the conidial germination of the fungus.
10. The changes in pH value and the osmotic pressure of the culture-solutions caused by the growth of those fungi seemed to have no relation with the accelerating as well as the checking power of filtrates.View full abstractDownload PDF (1072K) -
IV. Relation between Varietal Resistance to Rice Blast and Some Physical and Chemical Properties of the Leaf Blade of RiceHazime YOSHII1941 Volume 11 Issue 2 Pages 81-88
Published: 1941
Released on J-STAGE: April 03, 2009
JOURNAL FREE ACCESS1) The toughness and the percentages of silica and nitrogen of the leaf blades of rice varieties were measured to find the relation between these properties and the varietal resistance of rice to the blast disease.
2) Rice varieties used for this purpose were Ban-Sinriki, Kamezi, Sensyo, Aikoku, Asahi, Ginbozu, Sinzyu-1, and Kamairazu.
3) These plants were water cultured during summer season under glass roof using modified KASUGAI's solution in which three times the normal quantity of nitrogen component was given.
4) Resistance to rice blast of these varieties was tested either by inoculating Piricularia oryzae to the plants, or examining the plants affected naturally by the blast fungus.
5) Comparing the results thus obtained with each other, it is found that the varietal resistance of rice to the blast disease is not correlated to the variation of these physical and chemical properties of rice varieties.View full abstractDownload PDF (508K) -
Seito TAKIMOTO1941 Volume 11 Issue 2 Pages 89-91
Published: 1941
Released on J-STAGE: April 03, 2009
JOURNAL FREE ACCESSA study was made on the Pythium isolated from diseased young cucumber plants in Hukuoka Prefecture and from soft rotten fruits of cucumber which was collected at Taikyu, Tyosen. The fungus in question appears to be undescribed. It, therefore, is described new with the following diagnosis:
Pythium cucurbitacearum n. sp.
Hyphae on culture media variable in width, mostly large, frequently deformed, 6-10μ in diameter, with granular content: aerial hyphae void of granular content, slender, filamentous, 4μ in diameter: zoosporangia mostly spherical, or egg-shaped provided with papilla, measuring 20-32×20-30μ (developed on host plant), and 12-15×10-13μ (on corn agar); oogonia spherical, rich in protoplasma, 22-25μ in diameter; antheridia basal, nearly spherical: the minimum temperature for growth being slightly below 10°C, optimum temperature about 33°C, and maximum temperature slightly below 40°C; causing damping-off of seedlings of cucumber (Cucumis sativa L.), and oriental pickling melon (Cucumis melo L. var. conomon Makino), and soft rot of fruits of watermelon (Citrullus vulgaris MAX.), melon (Cucumis melo L.), and rag gourd (Luffa aegyptica MILL.); occurring in Hukuoka Prefecture and Tyosen.View full abstractDownload PDF (5089K) -
Y. IWATA1941 Volume 11 Issue 2 Pages 92-93
Published: 1941
Released on J-STAGE: April 03, 2009
JOURNAL FREE ACCESSDownload PDF (2440K) -
H. OKAMOTO1941 Volume 11 Issue 2 Pages 94-96
Published: 1941
Released on J-STAGE: April 03, 2009
JOURNAL FREE ACCESSDownload PDF (6844K)
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