对夜蛾科幼虫高毒力的苏云金芽孢杆菌菌株及其晶体蛋白特性

本文对自德国土壤中分离的８株苏云金芽孢杆菌进行毒力测定和晶体蛋白特性的研究。生物测定结果表明，８株Ｂｔ中除Ｓ２１－１、Ｓ２１－１３对甜菜夜蛾无毒性外，对夜蛾科的４种供试昆虫均有很高的毒效，４８小时校正死亡率高达８０％～１００％；扫描电镜观察和ＳＤＳ－ＰＡＧＥ晶体蛋白电泳结果可知，Ｓ１１－６和Ｓ２１－１３２个菌株只有一种菱形晶体和一条相应的１３５ＫＤａ主带，其余６个菌株均有菱形和方形两种晶体，以及两条相应的１３５ＫＤａ和６５ＫＤａ主带。另对晶体的特性与其毒力的关系进行了讨论。     

截头堆砂白蚁补充型繁殖蚁形成的生物学特性及其在群体中的作用

截头堆砂白蚁形成补充型敏殖蚁的生物学特性主要为：１．补充型从若 产生，一般都具有繁殖功能。２．补充型只能一雌一雄并存。对培养了三年的２０个群体进行解剖，每个群体只存在一对补充型。３．补充型可以再续；人为除去第一个补充型以后，可以重新形成一对型。４．人为除去第一个补充型后，重新形成补充型的发育历期比自然形成的补充型历期平均长２．４天，其繁殖功能亦有一些差异。６．自然淘汰后形成的补充型的繁殖功能与自然     

捕食线虫性真菌——少孢节丛孢菌CIMH1株捕食特性研究

本研究首次对国内土壤中分离出的捕食线虫性真菌—少孢节丛孢菌ＣＩＭＨ１株（Ａｒｔｈｒｏｂｏｔｒｙｓｏｌｉｇｏｓｐｏｒａｓｔｒａｉｎ：ＣＩＭＨ１）捕食马线虫第３期幼虫的活性、效力及杀虫机理进行了试验。结果表明菌株生长环境对其捕食活性有很大影响。在２０℃、有氧条件、玉米粉浓度相对较低（０．４ｇ／Ｌ）、菌丝生长较稀疏的ＣＭＡ培养基中,捕食活性最佳。捕食线虫时,在虫体运动刺激及虫体内部某些物质诱导下,菌株会产生一些特殊捕食性结构,如粘性菌丝（Ｓｔｉｃｋｙｂｒａｎｃｈｅｓ）、粘性菌环（Ｓｔｉｃｋｙｒｉｎｇｓ）和粘性菌网（Ｓｔｉｃｋｙｎｅｔｗｏｒｋｓ）等。通过这些功能性构造,菌株将线虫捕获并杀死消化。少孢节丛孢菌ＣＩＭＨ１株在最佳条件下,对马线虫第３期幼虫的平均捕食效力为７８．１５±３．８％。     

蝇蛆几丁糖对几种细菌抑制作用的研究

蝇蛆几丁糖对３种细菌均表现出不同程度的抑制作用,但在不同ｐＨ值条件下的抑菌效果不同,以ｐＨ５．５条件下抑菌效果较好,且随几丁糖质量浓度的升高,抑菌效果也相应增加。     

pH对紫彩血蛤幼虫发育的影响

ｐＨ对紫彩血蛤（Ｎｕｔａｌｉａｏｌｉｖａｃｅａ）幼虫生长、存活和变态有影响,ｐＨ６．４４～９．５１时培养幼虫均能得到变态的稚贝,说明ｐＨ对幼虫变态率影响较小,但对幼虫存活率影响较大;ｐＨ８．００～８．４７时,存活率较高,为９１．０％以上,高于或低于此ｐＨ范围,其存活率呈下降趋势;ｐＨ９．５１时最低,仅为３４．０％。低ｐＨ组在培养早期幼虫出现畸形,死亡较多,而高ｐＨ组则在培养后期死亡较多     

Cross-bred Cattle Protected against Hyalomma anatolicum anatolicum by Larval Antigens Purified by Immunoaffinity Chromatography

Antigens from larvae of Hyalomma anatolicum anatolicum were extracted and purified by immunoaffinity chromatography using immunoglobulin ligands from cross-bred animals immunized with soluble larval antigen. Affinity-purified antigen (Aff-TLE) and a total larval extract (TLE) were used to immunize cross-bred (Bos indicus×Bos taurus) cattle. The group immunized with Aff-TLE rejected 71.6% of larvae and 77.3% of nymphs. However, the rejection percentages were lower in the TLE-immunized group. No significant changes in the feeding period, moulting percentages or moulting period of engorged larvae and nymphs were recorded. There was, however, a significant decrease in the number of resultant nymphs p<0.01) and adults (p<0.01) in the ticks fed on the Aff-TLE-immunized group. The Aff-TLE antigen was 93.3% purified. SDS-PAGE analysis identified a 39 kDa protein, reported for the first time, as the antigen responsible for the induction of resistance in the host.     

茶皂素对雷公藤乳油防治茶尺蠖幼虫的增效作用

测定了茶皂素对雷公藤乳油防治茶尺蠖幼虫的增效作用。结果表明,用1、2、4mg/ml茶皂素浸叶处理,对茶尺蠖2龄幼虫的毒杀作用不明显,第7天的毒杀效果只有27.03%~37.84%。用雷公藤乳油0.8、1.6、3.2、6.4mg/ml和12.8mg/ml浸叶处理,对茶尺蠖2龄幼虫的毒杀效果在第7天分别为27.27%、33.78%、40.54%、56.76%和63.51%。在0.8mg/ml浓度的雷公藤乳油中加入4mg/ml的茶皂素,对茶尺蠖幼虫的毒杀作用(84.42%)显著高于加1mg/ml茶皂素的毒杀效果(68.83%);而加入2mg/ml和4mg/ml的防效差异不显著。向不同浓度的雷公藤乳油中加入2mg/ml茶皂素,对茶尺蠖2龄幼虫的共毒系数在第1、3、5、7天分别为667.68、981.61、1706.15和1209.76,即增效5.68~11.10倍,达到相同的使用效果可减少雷公藤用量85%以上。对茶尺蠖4龄幼虫增效1.00~6.91倍,减少雷公藤用量50%以上。     

文蛤浮游期发病幼虫细菌群落分析和致病菌的分离鉴定

为研究文蛤育苗过程中幼虫病害及其主要致病菌,实验通过构建细菌16S rDNA克隆文库、病原菌分离纯化、人工感染和药敏实验等方法对育苗场发病的浮游期文蛤壳顶幼虫样品进行了系统分析。结果显示,发病的文蛤壳顶幼虫细菌群落多样性低,地中海弧菌占比高达75%以上,推断其可能为引发此次幼虫发病的主要致病菌。从发病幼虫的匀浆组织中分离获得该优势菌株,测序及系统发育鉴定为地中海弧菌。人工感染实验确定了其致病性,菌株US2-01在1.0×10⁶ CFU/mL的菌液浓度下浸泡感染文蛤浮游幼虫,96 h累计死亡率为84%。药敏实验表明,地中海弧菌菌株US2-01在12种抗生素的测试中对常用的青霉素、氨苄西林、红霉素等抗生素具有一定的耐药性,对四环素和多西环素中度敏感,对头孢他啶、庆大霉素、卡那霉素等其余7种抗生素呈现高度敏感。本研究首次报道了地中海弧菌为文蛤浮游期幼虫致病的一种潜在病原,研究结果可为文蛤幼虫疾病研究及贝类苗种培育过程中的病害防控提供科学依据。     

Pacific cod in the Anthropocene: An early life history perspective under changing thermal habitats

The rapid decline in Pacific cod (Gadus macrocephalus, Gadidae) biomass following multiple Gulf of Alaska marine heatwaves (2014–2016 and 2019) may be one of the most dramatic documented changes in a sustainably managed marine fishery. As such, fisheries managers are exploring new recruitment paradigms for Pacific cod under novel environmental conditions. In this review, we address the challenges of managing and forecasting Pacific cod populations in the Eastern Pacific where thermal habitats for early life stages are undergoing varying rates of change across space and time. We use observational data to examine changes in distribution, abundance and demographics of the population from 1993 to 2020, and model contemporary and future changes of thermal habitat for both spawning success and age-0 juvenile growth potential. Results indicate that reduced spawning habitat and early life stage abundance may be a precursor to regional population decline, but the recent apparent increases in size-at-age of pre-recruits will have unknown impacts on future recruitment in these regions. We contend that continued monitoring of early life stages will be necessary to track changes in phenology and growth that likely determine size-at-age and the survival trajectories of year classes into the adult population. These include complex size- and temperature-dependent energetics spanning seasonal habitats through the first winter. Climate-ready management of Pacific cod will, therefore, require new process investigations beyond single-season surveys focused on one-life stage.