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Volume 16 (1952)
- Issue 3-4 Pages 97-
- Issue 2 Pages 49-
- Issue 1 Pages 1-
Volume 16, Issue 2
Displaying 1-8 of 8 articles from this issue
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Wataro YAMAMOTO1952 Volume 16 Issue 2 Pages 49-53
Published: May 31, 1952
Released on J-STAGE: April 21, 2009
JOURNAL FREE ACCESS1. The pycnospores of the sooty mould fungus, Capnodium fuliginodes REHM, germinate well in the solutions of honeydews secreted by aphides and scale insects as well as in some plant decoctions. However, they germinate neither in redistilled water nor in both the solutions of glucose and sucrose, and scarcely in RICHARDS' nutrient solution. The pyncnospores of the fungus seem to be unable to germinate unless being reinforced by certain substances derived from some living organisms. It is inferred that the honeydew solutions as well as the plant decoctions contain a certain substance or substances wich stimulate the spore germination of the sooty mould fungus.
2. The pyncnopores of the fungus germinate well in the solutions of honeydews secreted by the aphides and scale insects, including Tichoregma bambusifoliae TAK., Aphis sacchari ZEHNT., Thoracaphis fici TAK., Pulvinaria psidii MASK., Pulvinaria polygonata COCK., and Tachardina theae GREEN et MANN. The growth of the germ tubes is also favoured in these solutions. The specific effect of the honeydew on the spore germination of the fungus does not appear distinctly according to the different kinds of aphides and scale insects.
3. The solutions of honeydews secreted by the aphides and scale insects were treated with charcoal, siliceous earth or Japanese acid clay, respectively, and the germination of the pycnospores was examined in these treated solutions. They germinated never in the honeydew solution treated with charcoal, but did well in the solution treated with Japanese acid clay or siliceous earth as well as in the untreated solution. The results of the germination tests stated above showed that the effective substance or substances stimulating the spore germination are perfectly adsorbed by charcoal, but not by Japanese acid clay and siliceous earth.
4. The solution of the honeydew secreted by Trichoregma bambusifoliae TAK. was kept for 8 or 16 hours continuously at 100°C in a Koch's steam sterilizer, and the germination of spores and the growth of germ tubes of the fungus were examined in the treated solution, and the results showed that both are rather better in the solution treated with heat than in the untreated one. Therfore, the effective substance or substances contained in the honeydew solution seem to be thermostable. The spore germination of the fungus is also favoured on normal agar media which contain enough biotin referred to as a growth promoting substance. It is suggested by the results obtained in the experiments that the effective substance or substances in the honeydews secreted by aphides and scale insects may be biotin or some allied substances.View full abstractDownload PDF (2648K) -
N. SUZUKI, I. URITANI1952 Volume 16 Issue 2 Pages 54-56
Published: May 31, 1952
Released on J-STAGE: April 21, 2009
JOURNAL FREE ACCESSSweet potatoes are often brown-rotted as a result of infection by Helicobasidum mompa TANAKA, Ceratostomella fimbriata (E. et H.) ELL, or Thielavia basicola ZOPF.
When a section of the affected tissue is mounted in EHRLIOH'S aldehyde reagent, a red color develops in the browned tissue and its periphery. An oily substance giving the same coloration with the reagent has been isolated from the browned tissues. The results of analysis of the oily substance, show that the latter consists of two compounds, the one, ipomoeamaron, first described by HIURA in 1943(3) as a sesquiterpene, having a formula C15H22O3, and the other, a terpene having a lower boiling point; both reacting positive with the reagent. The occurrence of these substances is usully accompanied with the browning of tissues.
The oily substance may play a roll in the resistance of the host tissue against the invasions of the above pathogens.View full abstractDownload PDF (2096K) -
II. Number and distribution of the nematode on the affected plantsK. GOTO, R. FUKATSU1952 Volume 16 Issue 2 Pages 57-60
Published: May 31, 1952
Released on J-STAGE: April 21, 2009
JOURNAL FREE ACCESS(1) Number and distribution of the nematode (Aphelenchoides or yzae YOKOO) were examined in relation to white tip of rice plants. On germinating the nematode fewer in number is found remaining in the seeds, but it could not be found any on the part of buds. On the seedlings just to be transplanted (6 to 7 leaf stages), the nematode could not be detected. In the tillering stage in the paddy field, the nematode exists in the cavity above the growing tip of the rudimentary culm, or on the young leaf surrounded by the innermost leaf_sheath (Fig. 1). In accompany with the growth of rice plant, distribution of the nematode shifts towards the upper part of the larger rolled leaf which is still enclosed completely in the sheath. At the latest part of the tillering stage and thereafter, the nematode becomes to increase rapidly in number.
(2) When the young ear develops to 5-6.cm in length, the nematode shows a tendency to assemble on the ear. At the stage of booting, this tendency becomes more apparent. The nematode distributes mostly sticking on the ear, and a certain percent of it enters into the pre-flowering glumes (Fig. 2). At earing the majority of the nematode comes to outside of the leaf sheath in accompany with the ear. At this stage and a while thereafter before flowering, the nematode exists mostly outside the glumes sticking on the surface, though the percentage in the glumes slightly increasing. The ratio of the outside nematode decreases suddenly during the period of flowering (about 6 days). This suggests the entering of the outside nematode into the glumes. However, detailed comparison of the number of the nematode between pre-and post-flowering stages reveals that a rapid increase in the glumes is a more important factor. Soon after the earing, a small number of the nematode is found remained inside the flag-leaf sheath, but thereafter it is confirmed rarely outside the unhulled grain.
(3) As a rule the more the white-tipped leaves per stem the more is the nematode detected. The nematode can also be detected frequently on apparently healthy stems (carrying stems) in affected fields. Its number is markedly less (about 1/8-1/10) as compared with that of the stems bearing white-tipped leaves. On the basis of detailed observations, the number of the "carrying stems" reaches to about 1.4 times of the stems bearing with white-tipped leaves.
(4) The main (seminal) stem is invaded more frequently than the tillers. The number of the nematode is numerous on the former, even when the white tip symptom was equal in grade. As regards-the position of grains on an ear, the nematode distributes slightly dense at the middle, followed by the lower part, and the terminal part is slightly sparse. In regard to the size of a grain, the larger one contains usually more of the nematode. It is remarkably decreased in empty unhulled grains.
(5) The rice plants developed from nematodecarrying seed grains grow up sometimes as carrying or no-nematode stems. (Tokai-Kinki National Agr. Exp. Station. Ishinden, Pref. Mie)View full abstractDownload PDF (359K) -
1. On the Pathogenicity of Pythium aphanidermatum on various plant seedlings.T. KUSUMOTO1952 Volume 16 Issue 2 Pages 61-62
Published: May 31, 1952
Released on J-STAGE: April 21, 2009
JOURNAL FREE ACCESS -
On the Polyphenol-oxidase in the Fungus Free Filtrate of Culture Media.H. TORIKATA, Y. KOMAI1952 Volume 16 Issue 2 Pages 63-68
Published: May 31, 1952
Released on J-STAGE: April 21, 2009
JOURNAL FREE ACCESS1. By means of cultural method the BAVENDAMM'S reaction of Alternaria Kikuchiana, a causal fungus of black spot disease of Japanese pear, is positive on its culture media. The writers have also found the laccase (polyphenoloxidase) reaction in the fungus-free filtrates of potatodecoction culture, showing blue color with guaiacum tincture. However, we did not find tyrosinase in them.
2. The optimum pH value of polyphenol-oxidase produced by the present fungus lies approximately at 8.0-8.3, using PARITZSCH'S borate buffer. When potatodecoction media containing 2% sucrose was used, the maximum value of Oxidase activity was obtained in 12 to 14 days after inoculation, but after about 30 days it was negligible. It is assumed, therefore, that the Oxidase activity is parallel th the growth curve of the mycelium. When different amounts of sugar was added to the media, the activity was most intensive in the culture solution containing 2% sugar, having no connection with the dry weight of the mycelium.
3. When the culture filtrate was dialysed through collodion semipermeable membrane, we found that the enzyme solution that remained in the bag did not cause the death of leaf tissue and the toxic substances contained in the solution outside the bag, had the ability to cause the death of the tissues showing black appearance.
4. Among the fungi belonging to the genus Alternaria, it was found that some species had positive reaction of Polyphenol-oxidase in their fungus-free filtrates of culture media. Many of them, however, do not attack pear leaves, thus there is no resulting necrosis of cells.
5. From the result of the above stated investigations, it was concluded that Polyphenol-oxidase produced by the present fungus did not cause the death of tissues in leaves and fruits of pear directly. It is presumable, however, that Oxidase has some connection with the process of blackening of the lesions.View full abstractDownload PDF (4384K) -
MASAKI YAMAMOTO1952 Volume 16 Issue 2 Pages 69-71
Published: May 31, 1952
Released on J-STAGE: April 21, 2009
JOURNAL FREE ACCESSThe present paper deals with the results of investigations of seventeen fungi collected in Oze District (Nikko National Park) in July of 1948.
So far as the writer knows, Cercospora Nicolai Bubak is a new addition to the mycological flora of Japan.
By comparing the characters of Leptosphaeria sp. parasitic to Rhododendron metternichii var. Degronianum with the original description of Leptosphaeria Rhododendri. he found that asci and ascospores of the original fungus are quite larger than those of the writer's fungus, so its taxononical study will remain in future.
Allium Iatissimum PROK., Trillium Tschonoskii MAXIM., Epimedium snlphrellum NAKAI and E. coelestre NAKAI are additional new hosts for Alternaria Allii NOLLA, Phyllosticta trillicola TOGASHI and Aecidium Epdmedii P. HENN. et SHIRAI respectively.View full abstractDownload PDF (2113K) -
K. HARA1952 Volume 16 Issue 2 Pages 71
Published: May 31, 1952
Released on J-STAGE: April 21, 2009
JOURNAL FREE ACCESSDownload PDF (609K) -
1952 Volume 16 Issue 2 Pages 73-85
Published: May 31, 1952
Released on J-STAGE: April 21, 2009
JOURNAL FREE ACCESSDownload PDF (8306K)
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