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1.
钉螺分布与滩地环境因子的关系   总被引:31,自引:3,他引:28  
长江中下游滩地钉螺的分布与滩地的地下水位关系显著,当地下水位为32cm左右时,钉螺密度和有螺框出现率分别达到其最大值。活螺密度(Y)与地下水位的回归方程为:Y=-1.9686+0.2512X-0.004013X^2;有螺框出现率(Y)与地下水位的关系为:Y=-55.9720+7.5689X=-0.1180X^2;5月份钉螺适宜在土壤含水率30%左右的土壤表层生活。当土壤含水率为28-30%时,滩面  相似文献   

2.
采用赖氨酸缺陷型酿酒酵母(Saccharomyces cerenisiae)L1原生质与肌醇缺陷型粟酒裂殖酵母(Schizosaccharomyces pombe)PM-5原生质体事例选育了葡萄酒发酵性能良好且具有降解苹果酸能力的酵母菌株。对融合子菌落形态、遗传稳定性、降解苹果酸能力和葡萄酒发酵性能进行了研究。结果表明:用促融合剂「30%聚乙二醇(MW6000)、0.02mol/L CaCl2和1  相似文献   

3.
采用DOCA硅胶管皮下埋入法建立大鼠心衰模型,从基因转录水平检测正常与心衰大鼠心肌组织中心肌收缩蛋白分子基因α-MHC、β-MHC、α-cardiacactin、α-skeletalactin表达的变化。结果显示:(1)心衰大鼠心肌收缩力指标dp/dtmax较正常大鼠明显降低(下降27.51%,P<0.01),(2)心衰大鼠与正常大鼠相比,心肌组织中α-MHC基因表达水平显著下降(降低21.43%,P<0.05),β-MHC基因表达水平显著升高(升高62.43%,P<0.01)、α-cardiacactin基因和α-skeletalactin基因表达水平未见明显改变,(3)α-MHCmRNA的含量与心肌收缩力指标dp/dtmax值之间存在正相关关系(r=0.4143,n=43,P<0.05),β-MHCmRNA的含量与dp/dtmax值之间存在负相关关系。(r=-0.3902,n=43,P<0.05)。这提示:心肌组织中MHC基因表达水平的改变是心衰时心肌收缩力降低的主要分子基础  相似文献   

4.
枫杨(Pterocarya stenoptera)水浸液灭螺实验研究   总被引:9,自引:0,他引:9  
采用枫杨的新鲜根皮、茎皮和叶的水浸液处理钉螺,并用五氯酚钠溶液处理和清水饲养钉螺实验作对照.结果表明,5%以上的枫杨各部水浸液对钉螺具有20%~100%的毒杀致死作用.处理时间在240h左右时,其死螺率可达93.5%~100%,含2.5%的新鲜枫杨叶和2.5%的新鲜乌桕叶、池杉叶、樟叶、羊蹄全株、青蒿全株等的混浸液,处理钉螺240h亦分别具有96.7%、93.3%、80%、100%、86.7%的灭螺效果  相似文献   

5.
本文研究了柯萨基B3病毒(CoxsackievirusB3)对正常人PBMC白细胞介素一2受体(mIL一2R)表达的影响,结果实验组为89.83±7.03%,对照组为52.5±6.13%,表明CoxsackievirusB3能作用于PBMC,使其mIL一2R表达明显减少(P<0.01),由此影响IL-2发挥正常的生物学功能,如促使T细胞增殖,NK细胞活化等,本文认为mIL-2表达减少可能是CoxsackievirusB组病毒所致心肌炎患者细胞免疫功能异常的原因之一。  相似文献   

6.
刺槐宽叶和四倍体无性系的组织培养   总被引:13,自引:0,他引:13  
1植物名称刺槐(Robiniapseudoacacia)优良无性系:Tetraploidlocust、Glgastypelocust。2材料类别带腋芽的茎段。3培养条件(1)启动培养基:MS+6-BA0.25mg·L-1(单位下同)+NAA0.05。(2)分化培养基和继代培养基:MS+6-BA0.5+NAA0.1+AgNO310,MS+6BA0.5+NAA0.1。上述培养基均添加3%蔗糖、0.6%琼脂。(3)生根培养基:1/2MS+IBA0.2+NAA0.2,添加2%蔗糖0.6%琼脂。培养基pH…  相似文献   

7.
枫杨水浸液灭螺实验研究   总被引:31,自引:0,他引:31  
采用枫杨的新鲜根皮、茎皮和叶的水浸液处理螺,并用五氯酚钠溶液处理和清水饲养钉螺实验作对照,结果表明,5%以上的枫杨各部水浸液对钉螺个有20-100%的毒杀致死作用,处理时间在240h左右时,其经可达93.5-100%,含2.5%的新鲜枫杨叶和2.5%的新鲜乌桕叶、池杉叶、樟叶、羊蹄全株、青蒿全株等的混浸液,处理钉螺240h亦分别具有96.7%、93.3%、80%、100%、86.7%的灭螺效果。  相似文献   

8.
应用钙离子荧光指示剂fura-2,对糖皮质激素(Glucocorticoid,GC)是否影响肝细胞内游离钙(Intracellular free calcium,[Ca2+]i作了初步探讨。结果发现,GC在短期内能升高肝细胞[Ca2+]i,水平,并具有明显的量效关系。以1.0μmol/L的Cortisol和10.0μmol/L的Dexamethasone效果最好。加入1.0μmol/L的Cortisol0.25min即可引起肝细胞[Ca2+]i的明显升高,到10分钟时效应达高峰。此时与静息状态的肝细胞[Ca2+]i水平相比,胞浆内游离钙升高了近3倍;与相应对照组比较,胞浆内游离钙升高具有明显的统计学意义,P<0.01。RU486为一种人工合成的糖皮质激素受体(Glucocorticoid receptor,GR)的拮抗剂,它可以取消GC升高肝细胞[Ca2+]i的效应,提示GC升高肝细胞内[Ca2+]i可能与GR介导有一定关系。鉴于GC升高[Ca2+]i时间较短,推测与肝细胞膜GR的非基因快速调节作用影响钙离子通道有关。  相似文献   

9.
枫杨,乌桕对钉螺毒性的研究   总被引:21,自引:2,他引:19  
在自然条件下,研究了枫杨、乌桕叶对钉螺生理生化功能的影响,结果表明,与草滩生态系统相比,枫杨和乌桕生态系统中钉螺糖原含量、总蛋白含量分别下降36.3、55.7和27.5、54.5%,谷草转氨酸(GOT)和谷丙转氨酶(GPT)比活增高2.7和2.6倍,死亡率升高62和41%。本文对抑螺化合物结构与作用关系进行了讨论.  相似文献   

10.
本文对延安市150例男性高血粘滞综合证患者的卡森粘度(CassonViscosity,CV、ηc)、卡森屈服值(Cassonyieldstress,CY,Tc)与另外十四项血流变指标的相关性进行了研究,36例男健康人作对照,以初步观察CV、CY的内在规律与临床意义,结果表明病例组CV与ηa(230S-1)、HRV、TK、IR呈正相关(P<0.01或<0.005);CY与ηa(230S、46S、5.75n)、MRV、LRV、AI呈正相关(P<0.01)与ESR负相关;CV与ηa(5.75S)、MRV、LRV、AI、Fib,CY呈负相关(P<0.01);对照组例数少,相关性差,待后观察。  相似文献   

11.
中国乌桕品种资源的调查研究   总被引:22,自引:0,他引:22  
本文报道对我国16省82县乌桕主产区进行乌桕品种资源调查的结果。通过性状比较研究划分为44个农家品种和11个无性系品种,并描述了这些品种的分布和性状。  相似文献   

12.
金代钧  黄惠坤   《广西植物》1990,10(4):351-358
本文报道提高乌桕林经济效益的研究成果。采取垦复、中度修剪、林下套种春花生或马铃薯等作物,适当施肥等综合抚育技术,低产乌桕林的经济效益可提高10倍以上。  相似文献   

13.
The introduced tree Sapium sebiferum (Euphorbiaceae) is considered a serious threat to the preservation of the coastal prairie region of Louisiana and Texas, although it is currently uncommon in the western part of the region. The objective of this study was to evaluate the potential effects of location, soils, and available moisture on the growth and survival of S. sebiferum in coastal prairie. In a field experiment, S. sebiferum mortality was significantly greater at a western site than at central and eastern sites. The greatest mortality and least growth of surviving plants occurred on a soil from the western region, regardless of site. A greenhouse study also found that S. sebiferum growth was lowest on the western soil. Watering frequency significantly affected S. sebiferum growth, except on the western soil. Sapium sebiferum growth responded to both nitrogen and phosphorus additions for all soils. Soil analyses revealed the highest sand, sodium, and phosphorus contents, and much higher electrical conductivity in the western soil. It is concluded that the soil examined from the western region is unfavorable for S. sebiferum growth, though not to the extent to preclude S. sebiferum completely. Evidence suggests that soil salinity may be the primary cause of the poor S. sebiferum growth at the western site.  相似文献   

14.
乌桕种子油脂含量与其水平地带性的关系   总被引:7,自引:0,他引:7  
黄惠坤  唐润琴   《广西植物》1989,9(2):187-190
乌桕Sapium sebiferum (L.)Roxb.在现有栽培区域内,幼龄树的种仁含油率和种子含油率的高低与水平地带性变化差异不大。而种子含蜡率和种子含油脂率.则随纬度降低而极显著增高。  相似文献   

15.
Trade-offs associated with maintaining herbivory resistance and herbivory tolerance are frequently inferred in plant life histories. Invasive success for many non-native plants is often attributed to novel resistance that repels native herbivores. Chinese tallow tree (Sapium sebiferum, Euphorbiaceae) is a non-native invader that threatens ecosystems throughout the southeastern United States, including imperiled coastal prairie regions. Low herbivore loads due to costly resistance are generally assumed to give Sapium a competitive advantage over native plants. We predicted that if Sapium experienced higher damage levels it would show significant decreases in growth and reduced ability to compete with native prairie vegetation. We conducted full-factorial, paired greenhouse and field experiments designed to assess the effects of simulated leaf herbivory on Sapium growth in the presence of prairie vegetation at different levels of light and nitrogen. Contrary to our expectations, neither low-intensity, chronic defoliation nor high-intensity, acute defoliation negatively affected Sapium seedlings in any resource combination in either experiment. These studies reveal that Sapium possesses considerable phenotypic plasticity, and herbivory tolerance is a newly appreciated trait that likely contributes to its invasive potential.  相似文献   

16.
夹竹桃、鱼藤、乌桕对锈同心舟蛾的毒杀活性   总被引:6,自引:0,他引:6  
林同  黎荣彬  陆宁将 《昆虫知识》2006,43(4):517-519
为有效控制锈同心舟蛾HomocentridiapictaHampson对木荷(SchimasuperdaGardn.etChamp.)的危害,用索氏提取法获得夹竹桃(NeriumindicumMill.)叶、鱼藤(DerristrifoliateLour.)叶和乌桕(Sapiumsebiferum(L.)Roxb.)皮的乙醇提取物,在室内分别测定3种植物提取物对锈同心舟蛾3龄幼虫的防治效果。实验结果和方差分析表明,3种植物提取物为锈同心舟蛾都具有防治效果,3.5d后,受试昆虫的校正死亡率都达到60%以上;其中以夹竹桃和乌桕的提取物对受试昆虫的影响最为明显,6d后,受试昆虫的校正死亡率都达到90%以上。3种植物对锈同心舟蛾的毒杀作用由大到小的顺序依次是乌桕、夹竹桃和鱼藤。  相似文献   

17.
Siemann E  Rogers WE 《Oecologia》2003,135(3):451-457
Invasive plants are often larger in their introduced range compared to their native range. This may reflect an evolved reduction in defense and increase in growth in response to low herbivory in their introduced range. Key elements of this scenario include genetic differences in defense and growth yet uniformly low rates of herbivory in the field that dissociate defense and herbivore damage for alien species. We conducted a laboratory experiment with Melanoplus angustipennis grasshoppers and Chinese Tallow Tree seedlings ( Sapium sebiferum) from its native range (China) and its introduced range (Texas, USA) where it is invasive. We caged grasshoppers with pairs of Sapium seedlings from the same continent or different continents. The amounts of leaf area removed from Texas and China seedlings, and their height growth rates, were indistinguishable when both seedlings in the pair were from the same continent. However, when grasshoppers had a choice between seedlings from different continents, they removed more Texas Sapium foliage than China Sapium foliage and height growth rates were higher for China Sapium seedlings compared to Texas seedlings. Grasshopper growth rates increased with greater Sapium foliage consumption. In a common garden in Texas, Sapium seedlings from Texas grew 40% faster than those from China. Chewing insect herbivores removed little Sapium foliage in the field experiment. Although grasshoppers preferred to feed on Texas Sapium when offered a choice in the laboratory, extremely low herbivory levels in the field may have allowed the Texas seedlings to outperform the China seedlings in the common garden. These results demonstrate post-invasion genetic differences in herbivore resistance and growth of an invasive plant species together with a decoupling of defense and herbivore choice in the introduced range.  相似文献   

18.
钉螺在枫杨防护林和芦林分布密度的比较研究   总被引:6,自引:1,他引:5  
通过对长江外滩枫杨防护林和芦林钉螺分布密度的调查比较,结果表明:枫杨林钉螺分布密度明显低于芦林;两种群落钉螺分布密度不同程度受长江洪泛的影响;两种群落中4种抑制钉螺的植物对钉螺分布密度的影响相似。  相似文献   

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