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翅多型现象在昆虫中广泛存在,比如蚜虫有有翅蚜和无翅蚜,无翅蚜无翅不能飞行。翅型分化是蚜虫对不良生态环境的适应策略。有翅蚜能飞行,使其逃离不良环境并找到新的栖息地;而无翅蚜繁殖周期短、繁殖量大,有助于维持一定的种群数量。影响蚜虫翅发育的因素有遗传因素和环境因素,由环境因素决定的翅的多型现象被称为翅的非遗传多型性。本文就蚜虫翅型分化的生态学意义、影响因素,以及蚜虫翅型分化的生理和分子机制进行了综述。关于影响蚜虫翅型分化的遗传因素的研究较少,部分研究发现豌豆蚜翅型由X染色体上的一对等位基因所控制。更多的研究表明蚜虫翅型分化受环境因素影响,影响蚜虫翅型分化的环境因素有光周期、温度、种群密度、共生微生物、天敌、杀虫剂及抗生素等,事实上这些环境因素往往不是单方面存在的。保幼激素、蜕皮激素等外源激素会影响包括蚜虫在内昆虫的翅型分化,蚜虫的拥挤效应最终可能也是通过激素调控发挥作用。外源激素可以作用于出生后的低龄若虫也可作用于预产期的成虫,比如给豆蚜中龄若蚜施加保幼激素处理后,会出现超龄若虫,而不是无翅蚜。相反,反-β-法尼烯(EBF)的刺激会诱导有翅蚜后代的产生。另有研究发现,上一代豌豆蚜注射蜕皮激素可以减少有翅后代数量,而通过RNA干扰(RNA interference, RNAi)EcR受体或施加EcR抑制物也会导致后代有翅个体增加。蚜虫翅型分化分子机制的研究起始于对同一基因型蚜虫有翅、无翅成虫个体的差异表达基因或差异表达蛋白。 相似文献
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Xiaoyang Wang Keyu Zhang Mi Wang Lifang Zhang Chenzhong Fei Chunmei Wang Yingchun Liu Feiqun Xue Taijun Hang 《Journal of veterinary pharmacology and therapeutics》2020,43(4):331-338
Ethanamizuril is a new triazine compound that shows potential for application in novel anticoccidial treatment. In this study, a pharmacokinetic model of ethanamizuril was established on the basis of the blood concentration of 81 experimental animals. The final model showed that ethanamizuril was distributed as a two-compartment model with first-order absorption after oral administration in chickens. Its clearance rate and volumn of central compartment distribution (Vc) were affected by age and body weight, and volumn of central compartment distribution (Vc) and volume of peripheral compartment distribution(Vp) were influenced by weight and infection. External verification revealed that the model had good prediction accuracy and stability. 相似文献
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[目的]探究植物提取液对水稻潜根线虫的抑杀活性,寻找防控水稻潜根线虫病的植物源农药。[方法]将川芎(根)、仙鹤草(全草)、苍耳(籽粒)、紫苏(叶)、豚草(茎叶)、大葱(根)、大蒜(块茎)、玉竹(叶)、辣蓼(全草)、小飞蓬(地上部茎叶)10种植物材料烘干、粉碎、过筛后,用乙醇作溶剂常温浸泡提取24 h后用滤纸过滤提取液定容,将获得的植物提取液稀释后,在室内测定其对水稻潜根线虫的校正死亡率。[结果]川芎提取液的杀线活性较强,苍耳、仙鹤草、紫苏、大蒜、豚草提取液的杀线活性次之,杀线活性最弱的是小飞蓬提取液。[结论]川芎等植物来自天然,环境相容性好,有可能成为防治水稻潜根线虫病的植物源农药。 相似文献
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[目的]解决望天树在人工繁育方面存在的技术难题。[方法]研究不同光照和土壤水分对望天树种子发芽率及出苗情况的影响。[结果]望天树种子在光照强度40%、土壤含水量60%的条件下发芽率最高。[结论]该研究为望天树的迁地保护、种群恢复及开发利用等提供一定的基础资料。 相似文献
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The objective was to determine the most favorable nitrogen (N) source ratio of ammonium (NH4+) to nitrate (NO3?) for aeroponic culture of Chinese fragrant solomonseal Polygonatum odoratum (Mill.) Druce seedlings. Seedlings were cultured with solutions based on 50% Hoagland formula containing 0:100, 10:90, 20:80, and 30:70 NH4+:NO3? ratios for 21 days. Activities of anti-oxidant enzymes and glutathione contents of leaves with treatments of 10:90 and 20:80 NH4+:NO3? ratios were higher than that of all-nitrate treatment, and malondialdehyde (MDA) concentrations were lower than that of all-nitrate treatment. The maximum quantum yield ?Po value was normal among all of the treatments, whereas the absorption energy ABS/CSm value with 20:80 NH4+:NO3? treatment was highest and the heat dissipation DIo/CSm value with 20:80 NH4+:NO3? treatment was lowest among all of the treatments. These results supported that moderate proportion of 20% NH4+ in the solution provided optimal growth condition for (P) P. odoratum aeroponic culture. 相似文献
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卤虫具有很高的水产应用价值,其生存的环境非常严酷。本文作者初步分析了生存在盐湖中的卤虫的生态学特征,探讨了水温、盐度、溶氧、pH以及风等环境因子对卤虫生存的影响,着重分析了卤虫适应不良环境的一些对策;卤虫的种群特征。 相似文献