Daiki Murayama - Academia.edu (original) (raw)

Papers by Daiki Murayama

Research paper thumbnail of Some Physical Properties of Northern Cereal Mosaic Virus

Journal of the Faculty of Agriculture, 1967

NCMV was found in eastern Hokkaido and in the north-eastern portion of the Main Island of Japan. ... more NCMV was found in eastern Hokkaido and in the north-eastern portion of the Main Island of Japan. It was identified as a virus disease in 1943. As it is not transmitted by mechanical inoculation with crude sap, and is transmitted only by a planthopper (Laodelphax striatellus FALLEN), few of the physical properties of this virus are known. The injecting method into insects was used in order to determine some properties of this virus. From this experiment it was known that the virus in the crude sap of the diseased plants and in viruliferous insects was transmitted to healthy planthoppers. The longevity in vitro of the virus was between 4 and 5 days at 5°C, but at room temperature there was no insect survival after 10 days. The thermal inactivation point of the virus was 50 to 55°C for 10 minutes. The dilution end point was between 10and 10in diseased plant juices, and 10and 10in viruliferous insects. Diseased plant tissues frozen for 1 month and 1 year under -35°C still retained their...

Research paper thumbnail of Antigenicity of Potato Leaf-Roll Virus

Proceedings of the Japan Academy, 1974

Research paper thumbnail of Studies on the properties of potato leaf roll virus by the aphid-injection method

Japanese Journal of Phytopathology, 1965

Research paper thumbnail of Latent Period and Retention of Potato Leaf-Roll Virus in its Vector, Myzus persicae

Japanese Journal of Phytopathology, 1974

Green peach aphids, Myzus persicae Sulz. fed on the Physalis floridana Rydb. plants infected with... more Green peach aphids, Myzus persicae Sulz. fed on the Physalis floridana Rydb. plants infected with potato leaf-roll virus (PLRV) for 3 hours, began to transmit the virus 9 hours after leaving the source plants. Aphids injected with extracts or blood from the viruliferous insects were also enable to transmit PLRV 6 hours after injection. The length of the latent period and the frequency of virus transmission in its aphid vector appeared to depend on the virus concentration within the vector. Inoculativity in the transmission of aphids tended gradually to increase till 24 hours after acquisition feeding or injection of extracts and blood from viruliferous insects. PLRV was detected in extracts and blood from aphids fed on the infected P. floridana plants for more than 3 hours, but no virus was recognized in them from insects given an hour's acquisition feeding. Even though the concentration of PLRV in the aphid vectors increased with the prolonged acquisition feeding, it decreased gradually with the time after leaving the source plants. The frequency of virus recovery from blood of the injected aphids also tended similarly to decrease gradually with the time after injection of the virus into aphids.

Research paper thumbnail of Further Studies on the Transmission and Retention of Inoculativity of Potato Leaf-Roll Virus in its Vector, Myzus persicae

Japanese Journal of Phytopathology, 1973

This paper reports the results of further investigations of the transmission and retention of ino... more This paper reports the results of further investigations of the transmission and retention of inoculativity of potato leaf-roll virus (PLRV) in the green peach aphid, Myzus persicae (Sulz.). The frequency of virus transmission, the length of the latent period, and the retention period of inoculativity of the virus in the injected aphids were dependen ton the virus concentration of inocula. Virus recovery from viruliferous aphid extracts was influenced by the length of the acquisition feeding period of the aphids used as sources of inoculum. However, irrespective of the length of the acquisition feeding period, the virus concentration in the aphids tended gradually to decrease after leaving the source plant. The virus was recovered from the guts and blood, but not from the salivary glands of aphids given a 4-day acquisition feeding period on infected plants. Virus recovery from the aphid blood was also dependent on the length of the acquisition feeding period of aphids used as sources of inoculum. PLRV was detected in the blood of aphids up to 2 days after injection with a massive dose of the virus solution using aphid extracts as the inoculum. The results of virus recovery with the blood of the injected aphids were the same as for those following an acquisition feeding period. Attempts to maintain the virus inoculativity in serial passage using extracts or blood of viruliferous aphids were unsuccessful.

Research paper thumbnail of An Attempt to Prepare Antiserum against Potato Leaf-roll Virus

Japanese Journal of Phytopathology, 1972

Research paper thumbnail of Purification and serology of bean yellow mosaic virus

Japanese Journal of Phytopathology, 1975

Purification and Serology of Bean Yellow Mosaic Virus Ichiro UyEDA*, Makoto KoJIMA'" and Daiki Mu... more Purification and Serology of Bean Yellow Mosaic Virus Ichiro UyEDA*, Makoto KoJIMA'" and Daiki MuRAyAMA"' .EN-RF* ･ rihn ax** ･ itrLLIk:e** : I >t ti ;ifira Ei vtd fi " K ,u x O xx wa LMW pt Pti; Arktract Isolate No. 30 oi bean yellow mosaic virus <BYMV) was purified from broad bean leaves by extraetion with O,1M Tris-HCI buffer, pH 7.0, containing O.05M EDTA and 1% 2-mercaptoethanol; repeated clarification with carbon tetrachloride and precipitatien with 4% polyethylene glycol <#6,OOO) fol!owed by differential centrifugation and sucrose density-gradient centrifugation. ISCO fractionator scanning patterns indicated a high degree of purity but serological results revealed the presence of some host contaminates. The yield of virus was abeut 2mgfleOg of bro'ad bean leaves. The titer of the antiserum against isolate No. 30 was 1!2048 by ring precipitin tests. Although the iutact virus particles could n6t diffuse in agar gel plates, a clear precipitin line was observed when O.5% SDS (or LIS) was added to the agar or virus suspension. Isolate No. 30 was compared serologically with a necrotic strain and a chlerotic spot strain of BYMV in agar ge! diiffu$ion test$. Spur reactions were observed between isolate Ne. 30 and these strains.

Research paper thumbnail of Transmission of potato leaf roll virus by three species of aphids

Japanese Journal of Phytopathology, 1965

Research paper thumbnail of Purification and electron microscopy of potato leafroll virus

Virology, 1969

A procedure for purification of potato leafroll virus (PLRV) from its plant host was improved. An... more A procedure for purification of potato leafroll virus (PLRV) from its plant host was improved. An extract from diseased Physalis $oridana plants was emulsified with an n-butanol-chloroform mixture. The virus in the aqueous phase was concentrated by centrifugation, the pellet was resuspended in 0.01 M phosphate buffer and subjected to emulsification with fluorocarbon (Daifron S-3). The virus, concentrated by additional centrifugation from the aqueous phase, was fractionated in a sucrose densitygradient column. When the final preparation was suspended in 0.01 M phosphate buffer at pH 6.0 and negatively stained by 2oJ, PTA at pH 5.5, the resulting suspension contained uniform particles 25 rnp in diameter (side by side) and with more or less hexagonal profiles. High infectivity was associated with the zone containing these particles. Preparations obtained from healthy plants and virus-free aphids by the same purification procedure did not contain these particles. Examination of ultrathin sections of the infected P. JEoridana and Datura stramonium plants by electron microscopy indicated that the virus occurred in some of the phloem cells. When PLRV particles were measured in crystalline array in ultrathin sections the size obtained (23 rnp diameters) agreed approximately with that of the purified virus particles.

Research paper thumbnail of Some Physical Properties of Northern Cereal Mosaic Virus

Journal of the Faculty of Agriculture, 1967

NCMV was found in eastern Hokkaido and in the north-eastern portion of the Main Island of Japan. ... more NCMV was found in eastern Hokkaido and in the north-eastern portion of the Main Island of Japan. It was identified as a virus disease in 1943. As it is not transmitted by mechanical inoculation with crude sap, and is transmitted only by a planthopper (Laodelphax striatellus FALLEN), few of the physical properties of this virus are known. The injecting method into insects was used in order to determine some properties of this virus. From this experiment it was known that the virus in the crude sap of the diseased plants and in viruliferous insects was transmitted to healthy planthoppers. The longevity in vitro of the virus was between 4 and 5 days at 5°C, but at room temperature there was no insect survival after 10 days. The thermal inactivation point of the virus was 50 to 55°C for 10 minutes. The dilution end point was between 10and 10in diseased plant juices, and 10and 10in viruliferous insects. Diseased plant tissues frozen for 1 month and 1 year under -35°C still retained their...

Research paper thumbnail of Antigenicity of Potato Leaf-Roll Virus

Proceedings of the Japan Academy, 1974

Research paper thumbnail of Studies on the properties of potato leaf roll virus by the aphid-injection method

Japanese Journal of Phytopathology, 1965

Research paper thumbnail of Latent Period and Retention of Potato Leaf-Roll Virus in its Vector, Myzus persicae

Japanese Journal of Phytopathology, 1974

Green peach aphids, Myzus persicae Sulz. fed on the Physalis floridana Rydb. plants infected with... more Green peach aphids, Myzus persicae Sulz. fed on the Physalis floridana Rydb. plants infected with potato leaf-roll virus (PLRV) for 3 hours, began to transmit the virus 9 hours after leaving the source plants. Aphids injected with extracts or blood from the viruliferous insects were also enable to transmit PLRV 6 hours after injection. The length of the latent period and the frequency of virus transmission in its aphid vector appeared to depend on the virus concentration within the vector. Inoculativity in the transmission of aphids tended gradually to increase till 24 hours after acquisition feeding or injection of extracts and blood from viruliferous insects. PLRV was detected in extracts and blood from aphids fed on the infected P. floridana plants for more than 3 hours, but no virus was recognized in them from insects given an hour's acquisition feeding. Even though the concentration of PLRV in the aphid vectors increased with the prolonged acquisition feeding, it decreased gradually with the time after leaving the source plants. The frequency of virus recovery from blood of the injected aphids also tended similarly to decrease gradually with the time after injection of the virus into aphids.

Research paper thumbnail of Further Studies on the Transmission and Retention of Inoculativity of Potato Leaf-Roll Virus in its Vector, Myzus persicae

Japanese Journal of Phytopathology, 1973

This paper reports the results of further investigations of the transmission and retention of ino... more This paper reports the results of further investigations of the transmission and retention of inoculativity of potato leaf-roll virus (PLRV) in the green peach aphid, Myzus persicae (Sulz.). The frequency of virus transmission, the length of the latent period, and the retention period of inoculativity of the virus in the injected aphids were dependen ton the virus concentration of inocula. Virus recovery from viruliferous aphid extracts was influenced by the length of the acquisition feeding period of the aphids used as sources of inoculum. However, irrespective of the length of the acquisition feeding period, the virus concentration in the aphids tended gradually to decrease after leaving the source plant. The virus was recovered from the guts and blood, but not from the salivary glands of aphids given a 4-day acquisition feeding period on infected plants. Virus recovery from the aphid blood was also dependent on the length of the acquisition feeding period of aphids used as sources of inoculum. PLRV was detected in the blood of aphids up to 2 days after injection with a massive dose of the virus solution using aphid extracts as the inoculum. The results of virus recovery with the blood of the injected aphids were the same as for those following an acquisition feeding period. Attempts to maintain the virus inoculativity in serial passage using extracts or blood of viruliferous aphids were unsuccessful.

Research paper thumbnail of An Attempt to Prepare Antiserum against Potato Leaf-roll Virus

Japanese Journal of Phytopathology, 1972

Research paper thumbnail of Purification and serology of bean yellow mosaic virus

Japanese Journal of Phytopathology, 1975

Purification and Serology of Bean Yellow Mosaic Virus Ichiro UyEDA*, Makoto KoJIMA'" and Daiki Mu... more Purification and Serology of Bean Yellow Mosaic Virus Ichiro UyEDA*, Makoto KoJIMA'" and Daiki MuRAyAMA"' .EN-RF* ･ rihn ax** ･ itrLLIk:e** : I >t ti ;ifira Ei vtd fi " K ,u x O xx wa LMW pt Pti; Arktract Isolate No. 30 oi bean yellow mosaic virus <BYMV) was purified from broad bean leaves by extraetion with O,1M Tris-HCI buffer, pH 7.0, containing O.05M EDTA and 1% 2-mercaptoethanol; repeated clarification with carbon tetrachloride and precipitatien with 4% polyethylene glycol <#6,OOO) fol!owed by differential centrifugation and sucrose density-gradient centrifugation. ISCO fractionator scanning patterns indicated a high degree of purity but serological results revealed the presence of some host contaminates. The yield of virus was abeut 2mgfleOg of bro'ad bean leaves. The titer of the antiserum against isolate No. 30 was 1!2048 by ring precipitin tests. Although the iutact virus particles could n6t diffuse in agar gel plates, a clear precipitin line was observed when O.5% SDS (or LIS) was added to the agar or virus suspension. Isolate No. 30 was compared serologically with a necrotic strain and a chlerotic spot strain of BYMV in agar ge! diiffu$ion test$. Spur reactions were observed between isolate Ne. 30 and these strains.

Research paper thumbnail of Transmission of potato leaf roll virus by three species of aphids

Japanese Journal of Phytopathology, 1965

Research paper thumbnail of Purification and electron microscopy of potato leafroll virus

Virology, 1969

A procedure for purification of potato leafroll virus (PLRV) from its plant host was improved. An... more A procedure for purification of potato leafroll virus (PLRV) from its plant host was improved. An extract from diseased Physalis $oridana plants was emulsified with an n-butanol-chloroform mixture. The virus in the aqueous phase was concentrated by centrifugation, the pellet was resuspended in 0.01 M phosphate buffer and subjected to emulsification with fluorocarbon (Daifron S-3). The virus, concentrated by additional centrifugation from the aqueous phase, was fractionated in a sucrose densitygradient column. When the final preparation was suspended in 0.01 M phosphate buffer at pH 6.0 and negatively stained by 2oJ, PTA at pH 5.5, the resulting suspension contained uniform particles 25 rnp in diameter (side by side) and with more or less hexagonal profiles. High infectivity was associated with the zone containing these particles. Preparations obtained from healthy plants and virus-free aphids by the same purification procedure did not contain these particles. Examination of ultrathin sections of the infected P. JEoridana and Datura stramonium plants by electron microscopy indicated that the virus occurred in some of the phloem cells. When PLRV particles were measured in crystalline array in ultrathin sections the size obtained (23 rnp diameters) agreed approximately with that of the purified virus particles.