Indigofera spicata (creeping indigo) poisoning of three ponies

Three ponies continuously grazed a pasture containing an estimated 24% Indigofera spicata (wet weight basis) for 4–6 weeks in April and May 2004. They developed ataxia, paresis, depression, muscle fasciculations, dysphagia, ptyalism and halitosis. Two also developed corneal opacity. One pony recovered with supportive treatment, but the other two were euthanased and necropsied. Neuropathology was not present in either case, but both livers had periacinar and periportal lymphocytic infiltrations and hydropic degeneration of mid‐zonal hepatocytes, with mild to moderate periacinar necrosis also evident in one. The I. spicata contained 2.66 mg 3‐nitropropionic acid (3‐NPA)/g dry matter and 1.5 mg indospicine/g dry matter. Indospicine, but not 3‐NPA, was detected in serum from both of the euthanased ponies and indospicine was detected in heart, liver and muscle from the one pony in which this assay was performed. The clinical syndrome closely resembled ‘Birdsville horse disease’ caused by I. linnaei and was similar to that reported in horses poisoned by the closely related species I. hendecaphylla and to 3‐NPA poisoning of other animals, including humans. 3‐NPA is thought to cause this neurological syndrome. To our knowledge, this is the first authenticated report of I. spicata poisoning in grazing animals. We also report here the first published evidence that 3‐NPA and indospicine exist in naturalised I. spicata in Australia and of the formation of indospicine residues in tissues of animals grazing paddocks infested with I. spicata.     

留兰香提取物体外抗菌作用初步研究

【摘要】 目的：研究留兰香提取物的体外抗菌作用。方法：采用管碟法测定留兰香提取物抑菌圈大小,采用试管2倍稀释法测定留兰香提取物对4种动物病原菌的最低抑菌浓度(MIC),判定抗菌效果。结果：留兰香水煎剂、醇提物、挥发油对4种动物病原菌有不同程度的抗菌作用,尤其是对猪葡萄球菌抑制效果比较明显,留兰香水煎剂Ⅰ的MIC为0.0313g/ml,醇提物Ⅲ的MIC为0.0625g/ml,挥发油Ⅴ的MIC为2.5μl/ /ml,挥发油Ⅵ的MIC为2.5μl/ /ml。结论：留兰香水煎剂、醇提物及挥发油体外有一定抑菌作用,不同提取方法所得提取物对试验菌抑制效果不同。     

穗花马先蒿对枸杞蚜虫的杀虫活性研究

[目的]为穗花马先蒿的开发利用和活性成分的研究提供依据。[方法]采用点滴法,研究穗花马先蒿乙醇提取物和石油醚、氯仿、乙酸乙酯、正丁醇和水5种萃取物对枸杞蚜虫的杀虫活性。[结果]用95%乙醇作提取剂,料液比1∶10,提取穗花马先蒿杀虫活性成分为15.30%。随着乙醇提取物浓度的增大和处理时间的延长,枸杞蚜虫的校正死亡率升高,浓度50.00 mg/ml时,48 h的校正死亡率达96.38%,毒力回归方程为y=2.220x+2.859。5种萃取物对枸杞蚜虫的杀虫活性的顺序为石油醚>正丁醇>氯仿>乙酸乙酯>水,石油醚萃取物48 h的校正死亡率达96.38%。[结论]穗花马先蒿乙醇提取物对枸杞蚜虫有较好的杀虫效果,48 h的LC50为9.21 mg/ml。不同极性萃取物的活性比较得知,杀虫活性成分主要是酯溶性的弱极性物质,分布在石油醚所在极性范围内。     

六种植物精油对家蝇的熏蒸及触杀毒力测定

测定了6种植物精油对家蝇的熏蒸及触杀作用。结果表明,6种精油均对家蝇有较强的熏蒸活性,且表现出一定的触杀活性。熏蒸毒力次序为:黄樟油(LC50＝1.7695 μL/L)＞八角叶油(1.8930 μL/L)＞肉桂油(5.8074 μL/L)＞留兰香油(6.2123 μL/L)＞香茅油(6.5801 μL/L)＞薄荷素油(9.4500 μL/L);触杀活性较好的为黄樟油,其次为 留兰香油、香茅油和薄荷素油,而八角叶油和肉桂油对家蝇的触杀作用较差。     

湖北麦冬外观品质的施肥模型研究

试验采用了二次回归正交设计,以氮、磷、钾配方施肥为研究对象,系统地进行了湖北麦冬外观品质施肥模型研究.结果表明,外观品质的最佳施肥模式为施N 546.2 kg/hm2、施P2O5 150.9 kg/hm2、施K2O819.7 kg/hm2,每50 9粒数为137粒.     

Chitosan Coatings Containing Mentha spicata Essential Oil and Zinc Oxide Nanoparticle for Shelf Life Extension of Rainbow Trout Fillets

ABSTRACT

The objective of the current study was to determine the effects of chitosan (CH) coatings containing Mentha spicata essential oil (MSO; 0.2 and 0.4%) and zinc oxide nanoparticle (ZnO; 0.2 and 0.4%) on chemical (total volatile basic nitrogen (TVB-N), 2-thiobarbituric acid reactive substances (TBARS) and peroxide value (PV)), microbial (total viable count, psychrotrophic count, Pseudomonas spp., and Enterobacteriaceae) and sensory (odor, color, and overall acceptability) properties of raw rainbow trout fillets during 14 days of refrigerated storage. Final microbial population of CH + MSO 0.4% + ZnO 0.4% and CH + MSO 0.4% + ZnO 0.2% retarded approximately 3–5 log CFU/g as compared to control groups (P < 0.05). At the end of storage time in control samples, TVB-N, TBARS, and PV reached 49.3 mg N/100 g, 3.31 mg malonaldehyde/kg, and 2.04 meq peroxide/kg lipid, while the values for the treated samples with MSO (0.2 and 0.4%) in combination with ZnO (0.2 and 0.4%) remained lower than 25 mg N/100 g, 2 mg malonaldehyde/kg, and 1.1 meq peroxide/kg lipid, respectively. The results indicate a potential use of CH coating containing MSO and ZnO as an effective type of antimicrobial packaging to maintain quality of rainbow trout fillets.     

铺地木蓝对不同程度淹水胁迫的生理响应

应用于感潮河涌两岸或具有季节性消涨带河道景观绿化的植物必须能耐水淹。本试验以铺地木蓝为对象,研究了不同淹水深度和淹水时间下,铺地木蓝的存活率、叶绿素含量、根系活力和根冠比等指标的变化情况,旨在探索铺地木蓝对淹水生境的响应机制,阐明铺地木蓝耐淹的生理机理,为该植物种用于感潮河涌或有水位变化的河道两岸绿化工程的可行性提供理论依据。结果表明,1)经过21 d淹水胁迫,铺地木蓝的存活率达到100%,虽然其叶绿素含量显著下降,但能够长时间维持在一个比较稳定的水平;2)随着淹水时间的延长,地下根的根系活力显著下降,全淹处理下淹水茎部无不定根形成,而半淹处理下淹水茎部不定根迅速形成且根系活力较强;3)淹水后铺地木蓝的茎叶生物量大幅下降,根冠比增加。     

留兰香挥发油熏蒸抑菌活性研究

为了确定留兰香挥发油对植物病原真菌的生防效果,进一步探讨其抑菌机制,以明确其在植物真菌病害防控方面的应用前景,本研究采用菌丝生长速率法测定了留兰香挥发油对番茄灰霉病菌Botrytis cinerea、小麦赤霉病菌Fusarium graminearum、水稻纹枯病菌Rhizoctonia solani和莴苣菌核病菌Sclerotinia sclerotiorum 4种植物病原真菌的熏蒸抑制作用,并利用GC-MS分析了留兰香挥发油的化学组分。结果显示,留兰香挥发油对4种供试真菌均有强烈的熏蒸抑制作用,EC_(50)均低于7.0μL/L。挥发油处理后番茄灰霉病菌菌丝畸变、表面塌陷,细胞膜被破坏、原生质泄漏,细胞质结构呈消解状,线粒体受损。通过GC-MS从留兰香挥发油中分离出30个组分,鉴定出其中24个组分,占挥发油总量的94.918%,其主要成分有L-香芹酮(57.468%)、D-柠檬烯(8.976%)等。研究表明,留兰香挥发油是理想的绿色熏蒸杀菌资源。     

NyPa宽叶草抗盐生理特性的初步研究

NyPa宽叶草为盐草属植物,是一种最近从国外引进的具有优良抗性的牧草和草坪兼用型多年生草本植物,填补了国内没有该属耐盐和盐生植物的空白,具有很高的开发潜力。为了了解NyPa宽叶草的抗盐特性,以耐盐牧草高羊茅为对照,对比研究了盐胁迫对NyPa宽叶草和高羊茅叶片的光合作用、光系统II（PSII）光化学效率、叶片的水分特征以及细胞膜透性的影响。结果表明：虽然在正常条件下高羊茅叶片的光合速率、气孔导度明显高于NyPa宽叶草,但是经过外加400 mmol/L的NaCl胁迫后,高羊茅叶片的水势、叶片相对含水量、光合速率、气孔导度、光系统II的实际光化学效率（ФPSII）等急剧下降,细胞膜透性和PSII反应中心关闭程度（1-qP）显著增加;而同样的NaCl胁迫却没有导致NyPa宽叶草这些指标的明显变化。研究结果表明,NyPa宽叶草比高羊茅抗盐性更强,是一种可以用来开发和改良盐碱、滩涂的抗盐牧草。     

日喀则地区穗花韭天然居群结实性状变异研究

乡土草种推广利用的先决条件是种子。本研究以日喀则地区16份穗花韭(Milula spicata Prain)居群为研究对象,结合22个环境因子对其7个结实性状进行巣式方差分析、变异分析、相关分析、主成分分析和聚类分析等,探讨穗花韭居群间和居群内结实性状的多样性、变异程度和变异规律。结果表明：7个结实性状在居群间存在极显著差异;表型分化系数在37.30%～82.35%之间,平均为55.49%,居群间的变异是穗花韭结实性状变异的主要来源;影响穗花韭结实的最关键结实性状是穗干鲜重、花序长宽和小花数,主要环境因子是经度、海拔、温度和降水;7个结实性状可提炼为4个主成分,累计贡献率97.39%;16个居群在欧式距离为5时可划分为4个类群。本研究可为穗花韭资源的保护提供科学依据。