Control of Colletotrichum fructicola on strawberry with a foliar spray of neutral electrolyzed water through an overhead irrigation system     

Yoshihiko Hirayama  Shunsuke Asano  Keiichiroh Watanabe  Yasuhiro Sakamoto  Masaaki Ozaki  Ken’o Okayama  Satoshi T. Ohki  Motoaki Tojo 《Journal of General Plant Pathology》2016,82(4):186-189

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Oocyte maturation and active motility of spermatozoa are triggered by retinoic acid in pen shell <Emphasis Type="Italic">Atrina pectinata</Emphasis>     

Masahiko Awaji  Toshie Matsumoto  Daisuke Ojima  Shunsuke Inoue  Michio Suzuki  Masaei Kanematsu 《Fisheries Science》2018,84(3):535-551

For recovery of the declining population of pen shells in the wild, the production of pen shell juveniles for transplantation or aquaculture is underway in Japan. For more stable juvenile production, artificial fertilization methods for pen shells are needed, but methods to induce oocyte maturation (meiosis resumption) used in other bivalves, which make oocytes fertilizable, were ineffective for pen shells. Here, we report evidence showing that retinoic acid (RA) has strong activity in inducing oocyte maturation and activating sperm motility in pen shells. Treatment of fully developed oocytes with 1.0 μM all-trans-RA (at-RA) induced germinal vesicle breakdown, a typical morphological sign of oocyte maturation, but 1.0 μM at-retinol and at-retinal, 2 mM ammonia, and 1.0 μM serotonin were ineffective. Treatment with at-RA for 30 min was sufficient for oocyte maturation and was more potent than its isomers, 9-cis- and 13-cis-RA. Parallel results were obtained for sperm motility activation. Oocyte responsiveness to at-RA increased during the final stage of ovary development. Artificial fertilization was successful only with the oocytes treated with at-RA, and fertilized eggs developed to D-shaped (veliger) larvae without apparent morphological abnormalities. These results indicate the possible application of RA for the artificial fertilization of pen shells.  相似文献   

A hydro-environmental watershed model improved in canal-aquifer water exchange process     

Chie Imagawa  Junichiro Takeuchi  Toshihiko Kawachi  Kei Ishida  Shunsuke Chono  Natsuki Buma 《Paddy and Water Environment》2011,9(4):425-439

Long-term simulation using the distributed hydro-environmental watershed model is efficacious for assessing irrigation impacts on hydrological cycle in detail and for implementing watershed management successfully. In this article, the previously developed hydro-environmental watershed model (HEWM-1) is improved in the water exchange process caused by surface water-groundwater interaction via drainage canals and/or underdrains. The time-varying stream flow in canals is described by the complete one-dimensional shallow water equations in a newly introduced submodel, the open channel flow submodel. This submodel coordinates with the other submodels: the tank, soil moisture and groundwater flow submodels which are interlinked in a cascade manner. The improved model (HEWM-2) is applied to an agricultural watershed covering an area from an alluvial fan onto a nearly level alluvial plain, to be validated. The simulation by HEWM-2 is informative for identifying whether any drainage canal is gaining or losing water in relation to groundwater level. It could thus provide useful information for conserving a complex network of drainage canals which also functions as a passage for aquatic animals like fishes.  相似文献   

Growth performance of juvenile kuruma shrimp,Marsupenaeus japonicus (Bate) fed diets replacing fishmeal with soybean meal          下载免费PDF全文

Mahbuba Bulbul  Shunsuke Koshio  Manabu Ishikawa  Saichiro Yokoyama  Md. Abdul Kader 《Aquaculture Research》2015,46(3):572-580

A feeding trail was conducted to evaluate the effect of lowering dietary fishmeal (FM) levels while increasing levels of dehulled soybean meal (SBM) on growth, nutrient utilization and body composition of juvenile kuruma shrimp, Marsupenaeus japonicas. Five experimental diets were formulated to be isoenergetic, isolipidic and isonitrogenous with decreasing FM levels from 40 to 16% while increasing SBM from 0 to 33% respectively. Quadruplicate groups of shrimp (initial wt = 1.5 g) were fed the test diets for 56 days under the flow‐through system. There were no significant differences in final weight (g) and specific growth rate (SGR, % day) among shrimp fed FM40, FM34, FM28 and FM22 diets respectively. Growth parameters significantly decreased in shrimp when fed FM16 diet, which was the lowest level of FM. Feed intake was positively correlated with the SGR of shrimp, and the lowest one was found in shrimp fed FM16 diet. Protein gain and retention, whole body lipid, arginine and methionine significantly decreased in FM16 fed group. Thus, it is concluded that dietary FM could be reduced down to 22% with SBM without compromising growth, nutrient utilization and retention, and whole body composition of kuruma shrimp.  相似文献   

Soybean leaf rugose mosaic virus, a new soilborne virus in the family Potyviridae, isolated from soybean in Japan     

Tomohisa Kuroda  Koshio Nabata  Takeshi Hori  Kouji Ishikawa  Tomohide Natsuaki 《Journal of General Plant Pathology》2010,76(6):382-388

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Assessment of species specificity of moulting accelerating compounds in Lepidoptera: comparison of activity between Bombyx mori and Spodoptera littoralis by in vitro reporter and in vivo toxicity assays     

Thomas Soin  Ellen De Geyter  Hadi Mosallanejad  Masatoshi Iga  David Martín  Shunsuke Ozaki  Shigeki Kitsuda  Toshiyuki Harada  Hisashi Miyagawa  Dimitra Stefanou  Georgia Kotzia  Rodica Efrose  Vassiliki Labropoulou  Danny Geelen  Kostas Iatrou  Yoshiaki Nakagawa  Colin R Janssen  Guy Smagghe  Luc Swevers 《Pest management science》2010,66(5):526-535

BACKGROUND: Dibenzoylhydrazine analogues have been developed successfully as a new group of insect growth regulators, called ecdysone agonists or moulting accelerating compounds. A notable feature is their high activity against lepidopteran insects, raising the question as to whether species‐specific analogues can be isolated. In this study, the specificity of ecdysone agonists was addressed through a comparative analysis in two important lepidopterans, the silkworm Bombyx mori L. and the cotton leafworm Spodoptera littoralis (Boisd.). RESULTS: When collections of non‐steroidal ecdysone agonists containing different mother structures (dibenzoylhydrazine, acylaminoketone, tetrahydroquinoline) were tested, in vitro reporter assays showed minor differences using cell lines derived from both species. However, when compounds with high ecdysone agonist activity were examined in toxicity assays, larvicidal activity differed considerably. Of note was the identification of three dibenzoylhydrazine analogues with > 100‐fold higher activity against Bombyx than against Spodoptera larvae. CONCLUSION: The present study demonstrated that species‐specific ecdysone‐agonist‐based insecticides can be developed, but their species specificity is not based on differences in the activation of the ecdysone receptor but rather on unidentified in vivo parameters such as permeability of the cuticle, uptake/excretion by the gut or metabolic detoxification. Copyright © 2010 Society of Chemical Industry  相似文献   

Evaluation of Meat and Bone Meal as Replacement for Protein Concentrate in the Practical Diet for Sutchi Catfish,Pangasius hypophthalmus (Sauvage 1878), Reared under Pond Condition     

M. Abdul Kader  Mahbuba Bulbul  Saichiro Yokoyama  Manabu Ishikawa  Shunsuke Koshio  M. Sakhawat Hossain  Gias Uddin Ahmed  M. Arshad Hossain 《Journal of the World Aquaculture Society》2011,42(3):287-296

An 80‐d feeding trial was conducted to evaluate meat and bone meal (MBM) as replacement of protein concentrate (PC) in practical diets for sutchi catfish, Pangasius hypophthalmus. Triplicate groups of juvenile sutchi catfish (initial weight 4.80 g) were stocked at the rate of 20,000 fish/ha in 12 earthen ponds (30 m² each). Four isocaloric diets (4.12 kcal/g) were formulated by replacing 0 (Diet 1, control), 33 (Diet 2), 67 (Diet 3), and 100% (Diet 4) PC protein with MBM. The growth parameters [final weight, % weight gain, and specific growth rate (SGR)] of fish fed Diets 1, 2, and 3 were not significantly different (P > 0.05) from each other but were significantly (P < 0.05) higher than those in Diet 4. The protein content in fish fed Diet 4 was significantly (P < 0.05) lower than the others. The total production of fish in different treatments ranged between 1917 and 2648 kg/ha/80 d. A simple economic analysis determined that the highest net profit (Tk. 52,965/ha) was obtained with Diet 2 and the lowest (Tk. 27,127/ha) with Diet 4 having 100% PC protein replacement. From the results of the study it is concluded that MBM can substitute up to 67% PC protein in catfish diet without hampering the growth and feed utilization.  相似文献   

Does trade openness reduce a domestic fisheries catch?     

Keita Abe  Gakushi Ishimura  Tetsuya Tsurumi  Shunsuke Managi  Ussif Rashid Sumaila 《Fisheries Science》2017,83(6):897-906

Although trade liberalization may increase a country’s welfare, its specific effect on a country’s fishing industry has not been well studied. By decomposing the effect of international trade into four parts, i.e., scale-technique effects (ST), the indirect trade-induced composition effect (IC), the indirect effect of trade intensity through income (ITC), and the direct effect of trade intensity (DTC), this study empirically investigates the effect of trade openness on country-level fisheries production. To take into account the endogeneity of trade openness and income, we adopt the instrumental variable approach. We find that a rise in trade openness reduces fisheries catch on average. In particular, the long-run effect is large. This result implies that future production is affected by current overfishing through stock dynamics. Our decomposed elasticities indicate that the ST and ITC dominate in the trade elasticity of fisheries catch. While ST implies that overfishing would be affected by trade, ITC may either establish an “overfishing haven”, similar to a “pollution haven” in the environmental literature, or production shift of fisheries to countries with lax regulation to pass stringent regulation, which is more likely to occur in high-income countries.  相似文献   

Dietary supplementation of β‐glucan improves growth performance,the innate immune response and stress resistance of red sea bream,Pagrus major          下载免费PDF全文

M.A.O. Dawood  S. Koshio  M. Ishikawa  S. Yokoyama  M.F. El Basuini  M.S. Hossain  T.H. Nhu  A.S. Moss  S. Dossou  H. Wei 《Aquaculture Nutrition》2017,23(1):148-159

A 56‐day feeding trial was conducted to evaluate the effects of supplemented diets with β‐glucan (BG) at four levels [0 (D1), 250 (D2), 500 (D3) and 1000 (D4) mg BG kg^?1] on red sea bream, Pagrus major. The obtained results revealed a significant increase (P < 0.05) in final body weight, weight gain, specific growth rate, feed intake, body protein content, lysozyme activity and tolerance against low‐salinity stress test in all BG‐supplemented groups when compared with BG‐free group. Furthermore, D4 group resulted in a significant increase in feed efficiency ratio, protein gain, protein and lipid digestibilities, serum bactericidal activity and peroxidase content when compared with D1 group (P < 0.05). Haematocrit and plasma protein content in D3 group were significantly higher than those in D1 group (P < 0.05). Interestingly, BG supplementation decreased glutamic oxaloacetic transaminase (GOT) in D2 group and reactive oxygen metabolites in D2, D3 and D4 groups when compared with D1 group. Following low‐salinity stress test, significantly higher amounts of secreted mucus were observed in fish fed D2 and D4 diets than those from fish fed D1 diet (P < 0.05). In conclusion, the supplementation of BG improves growth, stress resistance and immune response of P. major.  相似文献   

Effects of dietary copper nanoparticles and vitamin C supplementations on growth performance,immune response and stress resistance of red sea bream,Pagrus major          下载免费PDF全文

M.F. El Basuini  A.M. El‐Hais  M.A.O. Dawood  A.E.‐S. Abou‐Zeid  S.Z. EL‐Damrawy  M.M.E.‐S. Khalafalla  S. Koshio  M. Ishikawa  S. Dossou 《Aquaculture Nutrition》2017,23(6):1329-1340

A 60‐day feeding trial was conducted to determine the effects of copper nanoparticles (Cu‐NPs) and vitamin C (VC) on red sea bream. Besides the control diet (D1), six diets were supplemented with Cu‐NPs and VC [0/800 (D2), 0/1,000 (D3), 0/1,200 (D4), 2/800 (D5), 2/1,000 (D6) and 2/1,200 (D7) mg Cu‐NPs/VC per kg]. Cu‐NP was a significant factor on final weight (FBW), weight gain (WG) and specific growth rate (SGR), feed intake (FI), feed (FER) and protein efficiency ratios (PER), protein gain (PG) and protein retention (PR), body protein and lipid contents, protease (PA) and bactericidal activities (BA) and tolerance against stress (LT50%) (p < .05). In addition, BA and LT50% were significantly affected by either Cu‐NPs or VC (p < .05). Fish fed Cu‐NPs or/and VC‐supplemented diets showed higher FBW, WG, SGR, PG, PR, FI, PA, LA and BA values when compared with the control group (p < .05). FER, PER and body lipid content were significantly enhanced in D4, D5, D6 and D7 groups; meanwhile, body protein and LT50% were significantly enhanced in D5, D6 and D7 groups when compared with D1 group (p < .05). In conclusion, dietary Cu‐NPs or/and VC improved growth and health of red sea bream.  相似文献