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Volume 43 (1974)
- Issue 6 Pages 445-
- Issue 5 Pages 361-
- Issue 4 Pages 277-
- Issue 3 Pages 195-
- Issue 2 Pages 105-
- Issue 1 Pages 1-
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Volume 43, Issue 3
Displaying 1-11 of 11 articles from this issue
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Kazuhiko KURISU, Michio HIMENO1974 Volume 43 Issue 3 Pages 195-199
Published: June 28, 1974
Released on J-STAGE: July 01, 2010
JOURNAL FREE ACCESSRecently, flacherie virus particles were separated into the FV I and FV II (HIMENO et al., 1973). FV I correspondis to the flacherie virus reported by AYUZAWA (1972). This paper deals with the pathogenicity of FV I and FV II to silkworm larvae.
The results indicated that the larvae inoculated with FV II either per os or intrahemocoelically, showed similar syndrome and mortality to those of the larvae infected with FV I. Moreover, the larvae inoculated with FV II produced only FV II particles. These results suggest that the FV II particle is a virus and the pathogenicity is similar to that of FV I.View full abstractDownload PDF (611K) -
I. Changes of the susceptibility to the virus of mid-gut epitherial cells in the silkworm larvae treated with low temperatureYoshihiko ABE, Chihiro AYUZAWA1974 Volume 43 Issue 3 Pages 200-205
Published: June 28, 1974
Released on J-STAGE: July 01, 2010
JOURNAL FREE ACCESSChanges of the susceptibility of mid-gut epitherium in the silkworm larvae treated with low temperature, to the nuclear polyhedrosis virus, were studied by microscopical observation.
When the larvae were chilled at 5°C for 24hr just after the moulting without any feeding and inoculated with the polyhedra, the posterior portion of mid-gut in these larvae was heavily affected with virus, specific C. P. E. and polyhedra were formed in both cylindrical cells and goblet cells (Figs. 1 and 2), but in anterior portion of mid-gut, infected cells could hardly be seen as shown in Fig. 3. And most of larval body in these insect became shorter and died within 24-48hr after the inoculation of polyhedra.
In larvae which were chilled after the feeding following the moulting, and non-chilled larvae, polyhedral bodies could not be seen in both cylindrical cells and goblet cells as shown in Fig. 4. And most of these larvae died over of 72hr after the inoculation of polyhedra, showing the swelling of segmental membrane.
From these results, it was concluded that, usually cylindrical cells and goblet cells of mid-gut epitherium in the silkworm are not so susceptible to the nuclear polyhedrosis virus, but if the larvae are chilled at 5°C after the moulting without any feeding, the susceptibility of both cylindrical cells and goblet cells become higher.View full abstractDownload PDF (4692K) -
Shuichi IWAMORI, Sukemitsu SORITA, Katsuo OHYAMA1974 Volume 43 Issue 3 Pages 206-210
Published: June 28, 1974
Released on J-STAGE: July 01, 2010
JOURNAL FREE ACCESSSpraying ethephon (2-chloroethylphosphonic acid) causes abscission of mulberry leaves, thus enables mechanical harvesting of the leaves. The experiments were conducted to correlate the ethephon-induced abscission to the cellulase activity of the abscission zone.
Ethephon of 3, 000ppm was sprayed to potted mulberry plants in the first and second experiments, and to the field-grown plants in the third experiment. Leaves were collected at definite time intervals after the treatment. The tissue of 4mm in length, including abscission zone was sampled, homogenized in phosphate buffer (pH 6.8) and centrifuged. The supernatant, as crude enzyme preparation, was put into Ostwald's viscometer togather with 0.4% (Exp. 1, 2) or 0.8% (Exp. 3) carboxymethylcellulose in phosphate buffer. The activity of cellulase was measured as change in flow time at 0 and 20 hours after the mixture was put in.
In the first experiment a crack was observed at the abscission zone at 48 hours after the treatment. Cellulase activity increased considerably at 36 and 48 hours after the treatment. In the second experiment using very young leaves, however, no sign of abscission nor any increase in cellulase activity was observed up to 72 hours after the ethephon treatment. In the third experiment cellulase activity began to increase one day after the treatment when no leaves abscised yet, then continued to be high level up to four days after the treatment when essentially all leaves abscised.
Excised leaves were enclosed in glass jar for one hour, and ethylene evolution was measured by gas chromatography. Ethylene evolution from the ethephon-treated leaves was highest at 3hours after the treatment (45mμl/g/hr), then decreased steadily until three days after the treatment when the level was about the same as that from control leaves.
Most results showed thus fairly good correlation between ethephon-induced abscission of mulberry leaves and cellulase activity at the abscission zone.View full abstractDownload PDF (500K) -
III, Effects of photoperiods on voltinism of the silkworm fed on artificial dietKunio TAKAMIYA1974 Volume 43 Issue 3 Pages 211-216
Published: June 28, 1974
Released on J-STAGE: July 01, 2010
JOURNAL FREE ACCESSEffects of photoperiods on the voltinism (diapause or non-diapause induction) of silkworms, Bombyx mori L., reared on the artificial diet were studied. Silkworm larvae were reared at 28°C throughout under the two photoperiodic conditions. These conditions were short day (8L·16D; 9 a. m.-5 p. m., light, 5 p. m.-9 a. m., dark) and long day (16L·8D; 5 p. m.-9 a. m., light, 9 a. m.-5 p.m., dark). The artificial diet consisted of mulberry leaf powder, agar, potato starch, sucrose, soybean meal, cellulose powder, L-ascorbic acid, citric acid and B-vitamins. The race of the silkworm, Hosho (a bivoltine Chinese race), was used throughout.
1. Being the silkworm larvae reared on the artificial diet, the photoperiodic conditions during the incubation period and the pupal stage did not effect to the voltinism of silkworm.
2. However, in larval stages reared on the artificial diet, a short day illumination (8L·16D) was more effective than a long day (16L·8D) to the change in diapause character of eggs laid by the moths which developed under different photoperiodic conditions. As a result, a short day for 8 hours gave a higher rate of diapause egg producers of moths of the bivoltine race.
3. The changes in diapause character of eggs by moths which developed under different daylengths during larval stages were recognized regardless of every larval stage treated by illumination, though there were some variations. And, the diapause character gradually rose as the silkworm grew, passed through a maximum at the 4th instar and finally fell off.View full abstractDownload PDF (627K) -
IV. Resistance of Pseudomonas mori (BOYER et LAMBERT) STEVENS to some factorsMamoru SATO, Kokichi TAKAHASHI1974 Volume 43 Issue 3 Pages 217-223
Published: June 28, 1974
Released on J-STAGE: July 01, 2010
JOURNAL FREE ACCESSThe effects of some physical factors on the growth and survival of Pseudomonas mori (BOYER at LAMBERT) STEVENS, the pathogen of bacterial blight of mulberry, were studied. The results obtained were summarized as follows
(1) The bacteria were killed almost completely by exposing to sunlight for about 30min. in May to October.
(2) The bacteria were killed almost completely by exposing to UV light (15W lamp, 40cm) for 40 sec. The survival rate was markedly increased when the concentration of bacterial suspension was higher than 108 per ml.
(3) The bacteria were able to grow at the temperature range of 2.5 to 34°C, and best growth was obtained at 28 to 32°C. Thermal death point in water was 46°C and 52°C, respectively when the concentration of bacteria was about 103 per ml and about 109 per ml. Thermal death point in dry air was 110°C. The bacteria survived longer in sterilized distilled water when the bacterial concentration was high and the temperature was low.
(4) The bacteria dried on a cover glass surived for 37 days in a desiccator.
(5) The bacteria were able to grow at pH 4 to 10, and maximum growth was obtained at pH 5 to 7.View full abstractDownload PDF (732K) -
V. Resistance of Pseudomonas mori phage to some factorsMamoru SATO1974 Volume 43 Issue 3 Pages 224-229
Published: June 28, 1974
Released on J-STAGE: July 01, 2010
JOURNAL FREE ACCESSThe author studied on the resistance of P. mori phage to some factors such as sunlight, ultraviolet light, temperature, dehydration, and pH. The following results were obtained.
(1) The grade of phage inactivation under sunshine depended on the strength of sunlight. The phages were completely inactivated by exposing to sunlight for 60min, in May, but not even for 180min in April.
(2) When the phage suspension was irradiated under a certain dosage of UV-light, the survival rate was higher corresponding to an increase of the initial phage concentration. The phages were inactivated almost completely by exposing to UV light at a distance of 40cm under 15W lamp (2537Å), for 40sec., if the initial phage concentration was less than 103 per ml.
(3) The phages were able to form plaques at the range of temperatures from 2.5 to 25°C. The highest plaque forming efficiency with clear plaque was obtained at about 20°C, and the plaque formation was retarded at low temperatures. The activity of the phages in sterilized water was relatively stable when they were in high concentration and kept at low temperature.
(4) The phages dried on a cover glass maintained their activity for more than 50 days in a desiccator.
(5) The phage activity was stable at the range of pH 5 to 9 in bouillon.
From the foregoing results, it is evident that P. mori phage is more resistant to dehydration and dry heat compared with that of P. mori.View full abstractDownload PDF (560K) -
I. Effects of growth substances on the development of shoots and organ formation from winter budsSeibi OKA, Katsuo OHYAMA1974 Volume 43 Issue 3 Pages 230-235
Published: June 28, 1974
Released on J-STAGE: July 01, 2010
JOURNAL FREE ACCESSTissue culture is one of the useful method for the study of physiological problems in woody plants such as flowering, bud dormancy and bud growth, because correlations among tissues or organs might be eliminated under defined conditions in tissue culture system. From this point of view, in vitro culture of isolated winter buds of mulberry tree was carried out. Results obtained are as follows.
1. When an excised winter bud (var. Kenmochi) was cultured on MURASHIGE and SKOOG'S medium containing benzyl adenine at 0.1 to 1.0mg/l, it sprouted within 2 weeks and a leaflet with stem grew in a month after planting. Continuous cultivation over more than a month caused differentiation of roots from basal part of the shoot.
2. Auxins, when they were added alone to the medium, exerted no effect on bud sprouting but induced callus at the base of the bud. When auxins were added together with benzyl adenine the time of rooting was fastened.
3. Adventitious buds were rarely formed on main nerves of leaflets on medium with benzyl adenine at 1mg/l.
4. There seemed to exist three types of varieties among 16 ones cultured on medium with benzyl adenine at 1mg/l. They are as follows.
Type A: Leaves with stem grow and shoot is formed.
B: A few leaves without stem grow and shoot is not formed.
C: Either leaf or stem hardly grows.View full abstractDownload PDF (6202K) -
Minoru FUJII1974 Volume 43 Issue 3 Pages 236-240
Published: June 28, 1974
Released on J-STAGE: July 01, 2010
JOURNAL FREE ACCESSPhysiological damages caused by the oral administration of fluorine in Bombyx mori were investigated. Results obtained are summarized as follows:
Alimentary canal of the larvae damaged by the fluorine became light green or light brown containing little mulberry leaves and the larvae exhibited light brown. The growth and molting of such larvae were delayed, indicating a symptom similar to that of flacherie. When larvae were affected by the fluorine, the incleasing rate in body weight declined at first, followed by the reduction in amount of food ingested, and then their development prolonged. In chemical analyses, ingested fluorine was mostly retained in alimentary canal, digestive juice and blood, and was very little found in integument and silkgland. From these results, it may be presumed that the death of silkworm larvae caused by the oral administration of fluorine can be mainly attributed to physiological damages of alimentary canal caused by the fluorine toxicity, because much amount of fluorine is accumulated in the wall of alimentary canal.View full abstractDownload PDF (2651K) -
Fujio KATSUMATA1974 Volume 43 Issue 3 Pages 241-244
Published: June 28, 1974
Released on J-STAGE: July 01, 2010
JOURNAL FREE ACCESSMorus boninensis KOIDZUMI has many peculiar characteristics, being very much different from other mulberry species, so it is safe to say that M. boninensis K. stands at the outermost position of the group of the Genus Morus.
Accidentally, we have seen, for the first time, (1) the mulberry female spike, which has the shape alike to that of the wheat, (2) the serra of the leaf-margin, on the apex of which there is no central point, (3) the idioblast in the mulberry leaves shows “Type A underdeveloped”.
By the wey, according to the native of the Bonin Islands it is said that silkworms cannot grow by feeding with the leaves of M. boninensis K., owing to the dislike of the worms against the leaves of this mulberry species.View full abstractDownload PDF (2184K) -
Keiji KURATA, Sumio TAKAHASHI1974 Volume 43 Issue 3 Pages 245-249
Published: June 28, 1974
Released on J-STAGE: July 01, 2010
JOURNAL FREE ACCESSThe concentration of formaldehyde gas in the silk-worm-rearing room sprayed with 3% formalin or fumigated with Neo PPS was determined by the use of 2-hydrazinobenzothiazol. Just after the spray of the formalin solution, the concentration of formaldehyde gas ranged from 250 to 300μg per a liter of air. With the time lapse after the spray the concentration decreased and about 40μg per a liter of air after 24 hours.
When Neo PPS (Para formaldehyde) was fumigated, the concentration was about 600μg per a liter of air just after the disinfection and decreased rapidly to about 60μg per a liter of air after 16hours.
It was found from the small-scaled eyperiment that the concentration of formaldehyde gas in air was increased in accordance with the increase in the concentration of formalin solution sprayed at varying temperature between 20 to 28°C (Fig. 4).View full abstractDownload PDF (501K) -
Kazuhiko KURISU, Tsuguo MATSUMOTO1974 Volume 43 Issue 3 Pages 250-252
Published: June 28, 1974
Released on J-STAGE: July 01, 2010
JOURNAL FREE ACCESSDownload PDF (412K)
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