Suppression of Verticillium Wilt in Eggplant by Some Fungal Root Endophytes   总被引：5，自引：0，他引：5  

Kazuhiko Narisawa  Hitoshi Kawamata  Randolph S. Currah  Teruyoshi Hashiba 《European journal of plant pathology / European Foundation for Plant Pathology》2002,108(2):103-109

One hundred and twenty-three fungal isolates were obtained from 225 root segments of eggplants, melon, tomato, strawberry and Chinese cabbage, grown as bait plants in a mixed soil made up of samples from different fields in Shizuoka, Japan. Isolates belonging to Mycelium radicis atrovirens (MRA), including Phialocephala fortinii, were the most prevalent in all the five bait plants. Eleven of the 123 isolates, after being inoculated onto axenically reared eggplant seedlings, almost completely suppressed the pathogenic effects of a post-inoculated, virulent strain of Verticillium dahliae. Seven of these 11 isolates had come from the roots of eggplant and included Heteroconium chaetospira, P. fortinii, and unidentified species of Fusarium, Penicillium, Trichoderma and MRA. P. fortinii, H. chaetospira, a non-sporulating isolate with white mycelium (SWM) and MRA were easily reisolated from root segments. Hyphae of H. chaetospira, P. fortinii and SWM colonized the root tissues of eggplant without causing apparent pathogenic symptoms. The mechanisms by which these endophytes confer resistance to infection by V. dahliae are unknown but the effectiveness of these fungi in a laboratory setting indicates that they have potential as biocontrol agents and merit further investigation.  相似文献   

Optimum planting density for Japanese oak (Quercus mongolica var.grosseserrata) based on spacing experiment with systematic design     

Morio Imada  Takashi Kunisaki  Nobuya Mizoue  Yukio Teraoka 《Journal of Forest Research》1997,2(2):89-93

A spacing experiment for Japanese oak (Quercus mongolica var.grosseserrata) with Nelder's design have been studied at the Kyushu University Forest in Hokkaido, since 1975. The oak seedlings were planted according to systematic spacings which were 20 levels varying gradually from 40,816 to 1,086 seedlings per hectare with concentric circular arcs (22 in number) and spokes (41 in number). In 1992 when the planted oak seedlings were 18-year-old, DBH, crown diameter, total height and clear length of the survival trees were measured. Based on the results obtained from analyzing the relationships between planting density and the mean values of each block, the optimum planting density should be 7,241 seedlings per hectare. The title is tentative translation from the original Japanese title by the authors of this paper.  相似文献   

Settling and raising postlarval abalone Haliotis diversicolor supertexta (Lischke) on microparticulate diets embedded in a layer of alginate     

Adrian Stott  Toshio Takeuchi  Yasuyuki Koike  & Osamu Imada 《Aquaculture Research》2003,34(7):561-567

Two 21 day experiments were conducted to determine whether microparticulate diets could be used to substitute for diatoms for raising (Experiment 1) as well as settling and on‐growing (Experiment 2) Haliotis diversicolor supertexta postlarvae. The experiments were conducted in 10 L flow‐through tanks and each diet had three replicate tanks. In experiment 1, three experimental microparticulate diets supplied by a commercial feed company, labelled SF‐15, SF‐15 (T) and JFY‐13–1, were used, and in experiment 2, SF‐15 and SF‐15 (T). Artificial diets were compared to diatoms in terms of supporting growth and survival. The survival rate for experiment 1 was lowest for JFY‐13–1 (0%) and highest for diatoms (12.9±0.8%). The final size of postlarvae fed SF‐15 and SF‐15 (T) was significantly greater than that of postlarvae fed diatoms, 973±193 μm and 996±220 μm compared to 786±141 μm. In experiment 2, a total number of 501 larvae settled onto plates covered with SF‐15, 254 on SF‐15 (T) and 1085 on diatoms. The highest survival rate was 33.1±6.9% for SF‐15 and the lowest was 17.3±5.0% for diatoms. However, the final length of postlarvae fed diatoms was significantly greater than SF‐15 and SF‐15 (T); 1018±379 μm compared to 728±89 μm and 717±90 μm. The artificial micro diets used in this study were comparable to diatoms in terms of grow and survival of postlarval H. diversicolor supertexta.  相似文献   

Changes in seawater tolerance during the development of eyed-stage embryos in shishamo smelt Spirinchus lanceolatus (Hikita)     

Shinya Mizuno  Yoshitaka Sasaki  & Kazushi Imada 《Aquaculture Research》2005,36(6):615-619

  相似文献   

Development of height curves for Japanese larch in relation to GIS-derived site index     

Yasushi Mitsuda  Shigejiro Yoshida  Morio Imada 《Journal of Forest Research》2003,8(3):199-207

The objectives of this study were: (1) to relate the height growth pattern to the GIS-derived site index, (2) to construct various types of polymorphic height curves, and (3) to select the most accurate height curve for Japanese larch (Larix kaempferi). A total of 14 dominant trees were felled for stem analysis. Richards' function was first fitted to the height/age dataset recorded from stem analyses of 14 trees, and its parameters (i.e., A, k, and m) were then estimated for each sample tree. The relationship between parameter A and the GIS-derived site index was significant, while that of parameters k and m were not significant. The 12 height curve equation forms developed from the Richards' function were then fitted to the dataset consisting of 563 observations of height, age, and GIS-derived site index derived from 14 trees. All height curves were unbiased and provided an equally good fit. The shape of the height curves differed among sites of different site indices. These results indicated that Richards' function was sufficiently flexible to represent the polymorphic height growth pattern of Japanese larch. Finally, the best-fit height curve was selected so that accurate height growth predictions would be possible at any given age and site.  相似文献   

The effects of human disturbance on a stingless bee community in a tropical rainforest     

Hiromitsu Samejima  Marfaizal Marzuki  Teruyoshi Nagamitsu  Tohru Nakasizuka 《Biological conservation》2004,120(4):577-587

Human disturbance of tropical rainforests may change pollinator communities indirectly as a result of changes in resource availability. We studied the mechanisms by which human disturbance affects a community of major pollinators, stingless bees, in Sarawak, Malaysia. We surveyed forest structure and flowering activity, and conducted a nest census and a bait-trap survey of stingless bees, both in primary forests and in forests disturbed by logging and shifting cultivation. The densities of late successional trees and large trees (diameter at breast height >50 cm) were higher in the primary forests than in the disturbed forests. The density of flowering trees was lower one year after logging, but recovered in old disturbed forests because of the active flowering of pioneer trees that became established after the disturbance. Stingless bees nest only in large trees, and nest density was positively correlated with the density of large trees. However, we found no relationship between the numbers of foragers and floristic parameters. Some species preferred nesting in dipterocarps, while others preferred dead trees. The results of the bait-trap survey also indicated that some species were abundant in the primary forests, whereas other species were abundant in the disturbed forests. These results suggest that human disturbance alters the species composition of the stingless bee community. Such changes in the bee community may affect the reproductive success of plants, and ultimately forest composition.  相似文献   

Conjugated linoleic acid-induced fatty liver can be attenuated by combination with docosahexaenoic acid in C57BL/6N mice     

Yanagita T  Wang YM  Nagao K  Ujino Y  Inoue N 《Journal of agricultural and food chemistry》2005,53(24):9629-9633

We investigated the effect of dietary combination of conjugated linoleic acid (CLA) and docosahexaenoic acid (DHA) to attenuate CLA-induced fatty liver in C57BL/6N mice. Mice were fed semisynthetic diets that contained either 6% high linoleic safflower oil (HL-SAF), 4% HL-SAF + 2% CLA, or 3.5% HL-SAF + 2% CLA + 0.5% DHA for 4 weeks. This 4 week feeding of CLA showed hepatic lipid accumulation concomitant with the decrease in adipose tissue weight in mice. However, 0.5% supplementation of DHA to the CLA diet could alleviate fatty liver without decreasing the antiobesity effect of CLA. The CLA diet promoted fatty acid synthesis in the liver, but DHA supplementation significantly attenuated the increase in enzyme activity induced by CLA. On the other hand, serum adipocytokines, leptin and adiponectin, were drastically decreased by CLA feeding, and DHA supplementation did not affect those levels. These results show that DHA supplementation to the CLA diet can attenuate CLA-induced fatty liver through the reduction of hepatic fatty acid synthesis without affecting adipocytokine production in C57BL/6N mice.  相似文献   

Plaque formation and replication of porcine parvovirus in embryonic swine kidney cell line, ESK cells     

H Kawamura  T Fujita  T Imada 《Nippon juigaku zasshi. The Japanese journal of veterinary science》1988,50(3):803-808

  相似文献   

Pathogenicity and distribution of egg-drop syndrome-1976 virus (JPA-1) in inoculated laying hens     

S Yamaguchi  T Imada  H Kawamura  T Taniguchi  M Kawakami 《Avian diseases》1981,25(3):642-649

Rhode Island Red laying hens that lacked hemagglutination-inhibition antibody were inoculated orally with the JPA-1 strain of adenovirus isolated from a flock affected with egg-drop syndrome-1976 in Japan and observed for 80 days. Inoculated hens laid abnormal eggs, such as shell-less, soft-shelled, and cracked eggs and those with loss of pigmentation, from 8 days postinoculation (PI). Fifteen out of 16 hens laid abnormal eggs. Egg-production rte fell from 94% to 50% between 13 and 16 days PI. When the abnormal eggs were excluded, egg production was 17%; then it recoverd slowly, reaching 67% by the end of the experiment. The virus was recovered from various organs of inoculated hens from 3 to 7 days PI. Fluorescent antigens of the virus were observed in the epithelial cells and desquamated cells from the epithelium of the uterus and isthmus 10 and 14 days PI.  相似文献   

Evaluation of the pathogenicity and immunogenicity of vaccinia virus to piglets     

T Imada  H Kawamura  T Nishimori  H Murata  M Narita  Y Honda  K Ishigaki 《Nippon juigaku zasshi. The Japanese journal of veterinary science》1989,51(1):96-104

The pathogenicity and immunogenicity of vaccinia virus were examined in order to evaluate the possibility of its application as a recombinant viral vaccine in pigs. Following scarification inoculation with vaccinia virus, a mild reddish papulation developed only on the scarified part of the skin. No symptoms of illness such as fever or stunting were noted. Vaccinia virus was recovered in titers from scarified skin 4 and 7 days after inoculation. Control piglets cohabited with inoculated animals remained normal for the whole 5 week observation period. Hemagglutination inhibition and indirect immunofluorescence tests detected antibodies against vaccinia virus in the inoculated piglets, whereas no anti-vaccinia virus antibodies were detected in the contact control animals. Antigen-induced blastogenic tests of peripheral blood lymphocytes from animals, revealed that lymphocytes obtained from inoculated donors 5 weeks after inoculation, had a higher stimulation index (P less than 0.05) than did those from uninoculated piglets. These results suggested that vaccinia virus would be useful as a recombinant viral vector for pigs.  相似文献