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Volume 48 (1982)
- Issue 5 Pages 559-
- Issue 4 Pages 419-
- Issue 3 Pages 245-
- Issue 2 Pages 141-
- Issue 1 Pages 1-
Volume 48, Issue 2
Displaying 1-17 of 17 articles from this issue
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Akira SHIRATA, Kokichi TAKAHASHI1982 Volume 48 Issue 2 Pages 141-146
Published: April 25, 1982
Released on J-STAGE: February 19, 2009
JOURNAL FREE ACCESSTo detect the presence of antifungal activity in arboreal plant tissues, cortical disks of one- to two-years-old shoots of 22 species belonging to 11 families including mulberry were placed on potato-dextrose agar (PDA) media seeded respectively with 6 species of fungi and bacteria, and assayed at 25C for 1-2 days and inhibition zones to microbial growth were observed (direct method). The disks of 11 species including mulberry and persimmon showed inhibition zones, indicating antifungal activity against Bipolaris leersiae and Fusarium roseum. The cortical disks of mulberry shoots showed antifungal activity on neutralised PDA, while those of persimmon showed antifungal activity only on acidified PDA. The cortical disks of mulberry shoots treated at -20C for 60min or in hot water at 60C for 10min failed to display any antifungal activity. Pieces of various organs of mulberry plant, i.e., leaf, petiole, cortical tissues of shoot and root showed antifungal activity, but antifungal activity could not be detected in xylem tissues of either shoot or root by this method. On the other hand, the acetone extracts from all of these pieces assayed by the direct method showed antifungal activity against B. leersiae. Antifungal activity could not be found in browned cortical tissues infected with pathogens by using the direct method, whereas acetone extracts showed antifungal activity.View full abstractDownload PDF (1342K) -
Akira SHIRATA1982 Volume 48 Issue 2 Pages 147-152
Published: April 25, 1982
Released on J-STAGE: February 19, 2009
JOURNAL FREE ACCESSPieces of bark cut out from one-year-old mulberry shoots (Morus alba L) cv. “Ichinose” showed antifungal activity (AA). When the pieces were placed on potato-dextrose agar (PDA) seeded with conidiospores from Bipolaris leersiae and were incubated at 25C for 1-2 days, mycelium inhibition zone appeared around the pieces. Pieces less than 0.1mm in length, however, did not show AA. The pieces were kept in moist conditions at 5 to 35C for various hours before being placed on the spore-seeded PDA. The intensity of AA increased when the pieces were kept at lower temperatures (5 and 10C), and it decreased, after an initial increase, at higher temperatures (15, 20, 30 and 35C). These changes were more conspicuous in the upper part of the shoots than in the middle and lower parts, and they were inhibited by dip treatment of the pieces with latex. The change of AA was confined to a region within 3mm length from the cut surface when using cut shoots. The AA was not detected in pieces incubated with the spore-seeded PDA for less than 4hr, but it was detected in pieces maintained on PDA for more than 6hr. The highest activity was found in the piece incubated with PDA for 18-24hr. When the pieces were heated at a temperature of more than 50C for 10min, it took a longer time for the pieces to show AA. When exposed to a temperature of more than 60C for 10min, AA could not be detected at least until 36hr after the treatment.View full abstractDownload PDF (1293K) -
I. Historical Analysis, Regional Pathogeographic Classification and Some Considerations of Disease Attributes of the EpidemicsE.S. POON, L.S LEU, C. LIU, W.T. CHENG1982 Volume 48 Issue 2 Pages 153-161
Published: April 25, 1982
Released on J-STAGE: February 19, 2009
JOURNAL FREE ACCESSThe pathogeographic history of sugarcane downy mildew in Taiwan was traced from 1909 to 1978. Three major epidemic periods were distinguished: namely, 1955-57, 1965 and 1973. Geographic distribution of the disease was also mapped. Hsinying area was identified as the primary disease focus and Pingtung area, the secondary disease focus. Areas of main damage, marginal damage, sporadic attack as well as nonepidemic region were distinguished. By means of cluster analysis based on three disease attributes (disease frequency, intensity and extensity), a pathogeographic classification of the sugarcane factory districts in Taiwan was presented. The classification corresponds with the disease regions demarcated in the geographic studies. Correlation of the spatial and temporal attributes (disease intensity, extensity, frequency and duration) was found and the meaning of such correlation was discussed.View full abstractDownload PDF (837K) -
II. A Preliminary Characterization of Host Factors in Four Pathogeographic RegionsE.S. POON, L.S. LEU, C. LIU1982 Volume 48 Issue 2 Pages 162-168
Published: April 25, 1982
Released on J-STAGE: February 19, 2009
JOURNAL FREE ACCESSThe disease and host attributes of four different pathogeographic regions from 1965-1978 were compared. The regions studied were Taichung (nonepidemic region), Huwey (sporadic region), Hsinying (region of main damage) and Pingtung (region of marginal damage). The disease attributes studied were disease intensity, extensity, frequency and duration. The host attributes were planting acreage of sugarcane and corn, the ratio of the two; ratio of disease-conducive varieties planted and disease potential index of the sugarcane population; the ratio of susceptible and resistant corn varieties and the practice of corn interplanting. Good correlation was found with the ratio of disease-conducive sugarcane variety, the disease potential index of the sugarcane population and disease incidence on sugarcane. Failure to find correlation with disease on sugarcane and the corn host population is probably due to the inadequacy of the historical data of corn. The host factors accounting for the different levels of disease intensities in the different pathogeographic regions were also discussed.View full abstractDownload PDF (771K) -
Setsumi ITOI, Hiroshi ISHIKURA, Toshiro MIYATA, Sakae ARASE, Hideo OIK ...1982 Volume 48 Issue 2 Pages 169-176
Published: April 25, 1982
Released on J-STAGE: February 19, 2009
JOURNAL FREE ACCESSStigmina mori, the causal fungus of mulberry branch blight, does not produce conidia on standard laboratory media. Monoconidial isolates of the fungus were cultured at alternating temperature of 20 to 5C under alternating 12-hr light-dark cycles (light 6:00-18:00, 20C; dark 18:00-6:00, 5C). Profuse sporulation occurred during growth for 50 to 60 days on epidermis removed mulberry shoot bark decoction agar plus 0.2% glucose. However, mulberry shoot bark decoction agar with epidermis yielded few conidia. Best results were also obtained when the fungus was cultured on mulberry shoot bark agar medium at alternating temperature of 15 to 5C under alternating 12-hr light-dark cycles (light 6:00-18:00, 15C; dark 18:00-6:00, 5C). Abundant sporulation occurred during growth for 27 to 32 days, Apparently there is a nutritional factor in mulberry shoot cortex tissues that promotes sporulation of S. mori. Conidia were produced at ends of hyphae, on short lateral hyphal branches, and also directly on hyphae. “Lesion-like sporulating area” was formed on mulberry shoot agar and mulberry shoot bark agar medium. There were significant differences in sporulation capacity between monoconidial isolates. Isolates S201-4, S201-5 and SE79-2 produced much more conidia than other isolates tested.View full abstractDownload PDF (1366K) -
Kazuo MIYAIRI, Akira MURAKAMI, Toshikatsu OKUNO, Ko SAWAI1982 Volume 48 Issue 2 Pages 177-181
Published: April 25, 1982
Released on J-STAGE: February 19, 2009
JOURNAL FREE ACCESSStereum purpureum was stationarily grown in PD medium at 29C for 20 days, and the laccase was purified from its culture filtrate by column chromatographies on DEAE-cellulose, DE-52, and Sephadex G-100. The purified enzyme was homogeneous in the electrophoresis as well as the ultracentrifuge, and the degree of purification was about 90-fold over the initial filtrate. The relative reaction rates for p-phenylenediamine, guaiacol, pyrogallol, catechol and hydroquinone were estimated to be 100, 86.9, 80.7, 79.7 and 45, respectively. The Km values for these substrates were 0.833, 0.760, 0.101, 2.63 and 2.0mM, respectively. The enzymatic reaction was strongly inhibited by several reducing agents, such as sodium hydrosulfite, cysteine and ascorbic acid, but no effects were observed by chelating agents, such as EDTA, αα'-dipyridyl and o-phenanthroline. In the feeding experiment using healthy nursery stocks of apple (cv. Fuji, 2 years old), the woody tissues showed browning at the extremely high concentration of laccase (5, 000 units). On the other hand, slight browning was observed on the cut-surface of the woody pieces, when the enzymatic solution (1, 000 units) was put on them. On the contrary, remarkable browning was recognized on the cut-surface of the boiled woody pieces at the lower concentration (100 units). It can be thought from these results that the laccase produced by the pathogen may participate in tissue-browning accompanied by the development of disease.View full abstractDownload PDF (1487K) -
Nobuyuki YOSHIKAWA, Tsuyoshi TAKAHASHI1982 Volume 48 Issue 2 Pages 182-191
Published: April 25, 1982
Released on J-STAGE: February 19, 2009
JOURNAL FREE ACCESSPurification of hop stunt viroid (HSV) from the infected cucumber leaf tissues has been accomplished. Comparative analysis of three extraction methods for low molecular weight RNA as well as HSV, that is, methods of Diener et al., Sänger et al. and Niblett et al., indicates no discernible differences in the yields of extractable RNA (30-32mg/kg of infected tissues). In this work, a more rapid extraction procedure was developed by modifying the direct phenol method of Diener et al. HSV was then purified to homogeneity from this extract by two-cycles of gel electrophoresis. Specific HSV band was consistently detected on 7.5% polyacrylamide gel electrophoresis. The yield of purified HSV was 30-40μg/kg of infected tissues. The dilution end point for infection of the purified HSV was between 10 and 100pg per ml, and its 50% infective dose (ID50) was 5ng per ml. The electrophoretic mobility of non-denatured HSV was markedly affected by acrylamide concentrations; apparent molecular weight of HSV was estimated at 52, 000-69, 000 daltons, whereas molecular weight estimate of 96, 000 daltons was derived from determination under denaturing condition. Denatured HSV was separated into two electrophoretic bands on polyacrylamide gels (5, 7.5 and 10%) containing 8M urea at 60C. Both slower migrating and faster migrating bands were infectious when bioassayed on cucumber plants.View full abstractDownload PDF (1000K) -
Nobumichi SAKO, Kazutoshi MATSUO, Fukuji NONAKA1982 Volume 48 Issue 2 Pages 192-198
Published: April 25, 1982
Released on J-STAGE: February 19, 2009
JOURNAL FREE ACCESSIncubation conditions for double antibody sandwich method of ELISA have been evaluated for detection of watermelon mosaic virus (WMV) and cucumber mosaic virus (CMV). When adsorbing specific antibody (globulin) to plate wells, there were no clear differences in ELISA absorbance values for WMV at three incubation temperatures of 6, 27 and 37C. However, when adding test samples to plate wells, combination incubation of 27C for 2hr and 6C for 14hr resulted in maximum values for the two viruses. In adding conjugated globulin to plate wells, higher values were obtained when incubated at 27C than at 37C for 3 or 4hr for WMV and for 1 to 4hr for CMV. Incubation at 6C showed lower values than those obtained at 27 or 37C for 1 to 4hr incubation times. Incubation at 27C was preferable over the conventional incubation temperature of 37C for detection of the two viruses in crude or purified preparations by ELISA.View full abstractDownload PDF (662K) -
Shigehisa KIYOSAWA, Hidekazu YAMAGUCHI, Masao YAMADA1982 Volume 48 Issue 2 Pages 199-209
Published: April 25, 1982
Released on J-STAGE: February 19, 2009
JOURNAL FREE ACCESSUsing the data on race frequencies of blast fungus through Japan obtained by Yamada et al.33), multiple regression analyses were carried out to get an equation for predicting frequencies for virulence genes in each prefecture in Japan. Resistance gene frequencies in each prefecture was calculated from growing areas of each variety in each prefecture in 16 years from 1961 to 1976. After arcsin transformation of frequencies of resistance genes and the corresponding virulence genes, 1) resistance gene frequencies, 2) the first and second component scores in principal component analysis computed from the resistance gene frequencies in the 16 years, and 3) means and slopes of resistance gene frequencies in each five or six year period when the 16 years were divided into three sections were used as three series of independent variables for a regression equation. The choice of a multiple regression equation from many equations obtained was performed to minimize the prediction sum of squares and to gain a better understanding. The virulence gene frequencies (F) in 1976 were expressed by F=0.14-1.89S2+1.44M1+0.53Da-0.62M12+0.63M1Dk+2.42S2Da, where S2 was the slope showing change of resistance gene frequencies from 1966 to 1971, M1 was the mean of resistance gene frequencies from 1972 to 1976, and Da and Dk were dummy variables for Pi-a and Pi-k resistance gene, respectively.View full abstractDownload PDF (1224K) -
Taeko TAKEUCHI, Yuji NAGAI1982 Volume 48 Issue 2 Pages 210-216
Published: April 25, 1982
Released on J-STAGE: February 19, 2009
JOURNAL FREE ACCESSIprodione-resistant strains of Botrytis cinerea were detected on tomatoes and cucumbers in greenhouses of Chiba prefecture first in spring 1980 and then more frequently in 1981 within one or two years of practical use of the fungicide. The rate of the resistant strains in all the isolates increased with the frequency of the fungicidal spraying. Percentage of diseased fruits caused by the resistant strains was 50% after five applications of the fungicide. On iprodione-containing potato sucrose agar (PSA) media, the resistant strains raised abundant aerial hyphae and developed mycelia on the media containing 6.25, 12.5, 200, 400, 800μg/ml iprodione respectively, though the mycelial growth was severely suppressed as compared with iprodione-free PSA media. However, the mycelial growth was less developed on the media with 25-100μg/ml iprodione. The resistant strains were as pathogenic as the sensitive strains against excised leaves of kidney beans. Strains resistant to iprodione showed cross-resistance to procymidone, vinclozolin and diclozoline, and they had ability of conidial germination and mycelial growth on the PSA media containing 6.25-400μg/ml of the above fungicides. Three out of four above fungicides except diclozoline untested did not show satisfactory effect against the resistant strains in excised leaf test using kidney bean leaves. Moreover, in greenhouses where the resistant strains of Botrytis cinerea had already been abundant, both iprodione and procymidone showed a reduced effect against gray mold of tomato.View full abstractDownload PDF (1218K) -
Nobuaki MATSUYAMA1982 Volume 48 Issue 2 Pages 217-219
Published: April 25, 1982
Released on J-STAGE: February 19, 2009
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Norio NISHIMURA, Kohei TOMIYAMA, Noriyuki DOKE1982 Volume 48 Issue 2 Pages 220-223
Published: April 25, 1982
Released on J-STAGE: February 19, 2009
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Masahiro OZAKI, Yoshio EHARA, Susumu YAMANAKA1982 Volume 48 Issue 2 Pages 224-227
Published: April 25, 1982
Released on J-STAGE: February 19, 2009
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Kohei TOMIYAMA, Kazuo SATO, Noriyuki DOKE1982 Volume 48 Issue 2 Pages 228-230
Published: April 25, 1982
Released on J-STAGE: February 19, 2009
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Takuo ISHII, Tomio USUGI1982 Volume 48 Issue 2 Pages 231-233
Published: April 25, 1982
Released on J-STAGE: February 19, 2009
JOURNAL FREE ACCESSSerologically specific electron microscopy (SSEM) proved to be useful for a diagnostic technique of citrus tristeza virus (CTV) and for a quantitative assay of CTV in crude tissue extract. The amount of CTV was much more in the young shoots than in other parts and differed with host species. There were no significant differences in number of CTV particles detected in the same host among three CTV strains.View full abstractDownload PDF (302K) -
Naotaka FURUICHI, Kohei TOMIYAMA, Noriyuki DOKE1982 Volume 48 Issue 2 Pages 234-237
Published: April 25, 1982
Released on J-STAGE: February 19, 2009
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Susumu SAKAI, Noriyuki DOKE, Kohei TOMIYAMA1982 Volume 48 Issue 2 Pages 238-240
Published: April 25, 1982
Released on J-STAGE: February 19, 2009
JOURNAL FREE ACCESSDownload PDF (295K)
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