鸣禽燕雀性腺的春秋季变化

利用测量及Ｈ－Ｅ染色等组织学方法研究了鸣禽燕雀睾丸和卵巢的体积,重量及组织学结构,着重比较了其春秋两季的差异。结果表明：春季性腺在体积和重量上都远大于秋季,组织结构也比秋季复杂。表明春季燕雀各种功能,行为较秋季活跃,复杂,可能与性腺结构的改变所导致的功能改变（如激素分泌）有关。     

不同嫁接方式对低温胁迫下甜瓜幼苗光合特性及抗氧化系统的影响

【目的】探讨不同嫁接方式缓解甜瓜幼苗低温伤害的生理机制,为生产实践中选取适宜嫁接方式、提高甜瓜低温抗性提供理论依据。【方法】以厚皮甜瓜品种‘早蜜1号’、‘冰糖雪梨’和薄皮甜瓜品种‘芝麻蜜’为接穗,‘白籽南瓜’为砧木,并以甜瓜自根苗为对照,考察3种方式嫁接苗（双根嫁接、靠接、贴接）在4 ℃低温处理前、中、后期（复温处理）叶片的光合色素含量、光合气体交换参数、细胞膜透性及抗氧化酶活性变化特征。【结果】(1)各甜瓜品种各类嫁接苗叶片的光合色素(叶绿素和类胡萝卜素)含量、光合气体交换参数（净光合速率、气孔导度、蒸腾速率、胞间CO2浓度）在低温处理下均比低温处理前显著降低,其中贴接处理的嫁接苗下降率最小,在复温后所有嫁接苗均比低温处理有所上升,并以贴接苗上升幅度最大;（2）各甜瓜品种各类嫁接苗叶片相对电导率(REC)、丙二醛(MDA)含量、过氧化氢(H2O2)含量及超氧阴离子(O2·-)产生速率在低温处理下均比低温处理前显著升高,并以贴接方式嫁接苗上升幅度最小,在复温处理后均比低温处理有所下降,并以贴接苗下降幅度最大;(3)各甜瓜品种各类嫁接苗叶片超氧化物歧化酶(SOD)、过氧化物酶(POD)和过氧化氢酶(CAT)活性在低温处理下均比低温处理前显著提高,在复温处理后均比低温处理显著升高,期间均以贴接苗上升幅度最为显著。【结论】3种嫁接方式均可显著增强低温胁迫和复温后厚皮和薄皮甜瓜幼苗抗氧化酶活性,有效降低活性氧积累,维持幼苗光合能力,提高幼苗低温耐受性,并均以贴接方式表现最佳。     

湖泊湿地生态服务监测指标与监测方法

湖泊湿地生态系统为人类提供了维持生存发展的多种生态系统服务,是社会经济可持续发展的重要基础。然而,全国范围内的湖泊湿地资源被大量开发利用,极大地削弱了湖泊湿地提供生态系统服务的能力,人类自身福祉也受到严重威胁。开展湖泊湿地生态系统服务动态监测能减少生态系统服务重复计算、推动生态系统服务管理实践。本文在分析湖泊湿地生态系统服务监测必要性的基础上,探讨了湖泊湿地生态系统服务监测指标选取的原则和思路,并初步构建了适宜于我国湖泊湿地生态系统服务动态评估、权衡分析和生态生产函数构建的最终服务和生态特征监测指标体系。最终服务是与人类效益有直接关联的生态功能量,生态特征指标是产生生态系统最终服务的关键指标,主要包括生态结构、生态过程和生态功能指标。供给服务和文化服务一般是最终服务,而调节服务既可以是中间服务(生态功能)又可以是最终服务,支持服务是中间服务(生态过程)。针对调节服务和文化服务评估的困难性及调节服务的重复计算问题,本研究提出通过宏观监测(3S技术监测)和典型湖泊湿地定位监测相结合的多尺度湖泊湿地生态系统服务监测方法,构建湿地监测项目开展生态系统最终服务和生态特征指标数据监测。本研究对构建生态生产函数、开展湖泊湿地生态系统服务动态评估和权衡分析具有重要意义,是生态系统服务从认知走向管理实践的重要基础。     

人巨噬细胞集落刺激因子（hM－CSF）基因的合成及表达

按照ｈＭ－ＣＳＦ基因的序列,适当采用大肠杆菌的优选密码子,人工合成了Ｍ－ＣＳＦ的基因。在合成中我们采用了分段克隆和顺次克隆的方法,在次级克隆中我们成功地使用了多片段分组连接和多片段一次克隆战略,还尝试了多种单链战术。在表达载体的构建中,充分利用人工合成基因的灵活性,通过对Ｎ端６个氨基酸编码的变换及ＳＤ序列－ＡＴＧ间距离的改变,获得了在大肠杆菌中高效表达的重组体,表达的蛋白量占菌体总蛋白的２９％。目的蛋白在表达中形成的包含体形式,简化了产物的纯化。     

The Effects of Age, Darkness and Nitrate on Poly-β-hydroxybutyrate Levels and Nitrogen-Fixing Ability of Rhizobium in Lupinus angustifolius

The effects of age, darkness and nitrate on nitrogenase activity, poly-β-hydroxybutyrate (PHB) and β-hydroxybutyrate dehydrogenase (BOHB DH) activity in Rhizobium lupini while in symbiosis with Lupinus angustifolius were assessed. It was concluded that PHB functions as a reserve material in root nodules and is involved in the maintenance of nitrogen fixation when the availability of photosynthates is restricted. PHB accumulation and the development of BOHB-DH activity did not take place until the peak of nitrogenase activity had passed. All three parameters reached a steady level when the host plant was approximately 24 days old. Deprivation of photosynthates due to continuous darkness resulted in major losses of PHB and BOHB-DH activity until N₂-fixation ceased. Nitrate addition without restriction of photosynthates resulted in diminished nitrogenase activity. Apart from a slight delay in accumulation. PHB levels were not affected. It was found important to standardize sampling since N₂-fixation was affected by plant culture and diurnal cycles.     

Ultrastructural Localization of Monoclonal IgG Antibodies for Antigenic Sites of Eimeria tenella Oocysts,Sporocysts, and Sporozoites1

Monoclonal IgG antibodies against sporozoites of Eimeria tenella were obtained from the ascites fluid of BALB/c mice. Oocysts, sporocysts, and sporozoites were exposed to medium 199, normal ascites fluid, or monoclonal antibodies 1A, 9D, 3D3II, or 2G8f. Specimens were then incubated with ferritin-conjugated goat anti-mouse IgG antibody. Ferritin was uniformly distributed over the surface of sporozoites exposed to 1A, 9D, or 3D3II; ferritin was localized in patches on sporozoites exposed to 2G8f. A uniform layer of ferritin was present on the inner layer of oocyst walls and on the Stieda body and outer surface of sporocysts exposed to 1A, 9D or 3D3II. In specimens treated with 2G8f, ferritin was present on the inner layer of the oocyst wall and the Stieda body, but not on the sporocyst wall. No ferritin was found on specimens exposed to medium 199 or normal ascites fluid. Monoclonal antibodies 1A, 9D, and 3D3II, but not 2G8f, caused complement-mediated lysis of sporozoites. These findings indicate that oocysts, sporocysts, and sporozoites of E. tenella contain common antigens specific for each monoclonal antibody tested.