松材线虫Bx-Daf-22基因鉴定及表达

[目的]为探究松材线虫(Bursaphelenchus xylophilus)抗逆态幼虫DL3(Dauer larvae3)形成的分子机理,对其鸟苷酸环化酶路径(cyclic guanosine monophosphate,cGMP)中的抗逆态基因daf-22进行了鉴定和表达研究。[方法]根据松材线虫基因组数据设计引物克隆松材线虫Bx-Daf-22基因。进一步对Bx-Daf-22基因编码的蛋白进行系统发育分析、保守结构域分析等生物信息学分析。应用BLAST比对技术在松材线虫基因组数据中鉴定得到固醇载体蛋白SCP2同源基因,命名为Bx-Daf-22。应用PCR技术扩增Bx-Daf-22完整蛋白编码区,分析同源序列系统进化和三维结构。[结果]结果表明,Daf-22作为路径的起点是cGMP路径中一个受体蛋白,可将起始信号传递到cGMP路径的膜结合受体上,再通过胰岛素相似信号途径(insulin like signaling,Insulin/IGF)中的β-胰岛素(β-insulin,Daf-28)以及转化生长因子β路径(transforming growth factor β,TGFβ-like)中的热激蛋白90(HSP90/Daf-21)连接从而调控线虫进入抗逆态。[结论]通过结构比对及基因表达量分析表明Bx-Daf-22与秀丽线虫Daf-22具有相近的功能。Bx-Daf-22编码的蛋白质具有固醇载体蛋白SCP2构域。因此松材线虫的cGMP路径与DL3形成具有直接相关。     

Effects of stocking density,ration and temperature on growth,survival and metamorphosis of auricularia larvae of the California sea cucumber,Parastichopus californicus

The combined effects of stocking density (0.2, 0.5, 1, 2, 4 and 8 inds/ml) and dietary microalgal ration (20,000 and 40,000 cells/ml) and the sole effect of temperature (10, 12, 14, 16, 18 and 22°C) on the specific growth rate (SGR), per cent survival and per cent metamorphosis of auricularia larvae of the California sea cucumber, Parastichopus californicus, were evaluated in two separate experiments. The SGR was not significantly affected by stocking densities in the range of 0.2 to 4 inds/ml, but was significantly reduced at 8 inds/ml. The SGR of larvae fed 20,000 cells/ml was significantly reduced in comparison to those fed 40,000 cells/ml. Larvae had significantly higher per cent survival and per cent metamorphosis when reared at densities of 0.2 and 0.5 inds/ml compared with those reared at 2–8 inds/ml. Microalgal ration level did not significantly impact survival or metamorphosis. Larvae reared at 16 and 18°C had significantly higher SGRs and per cent metamorphosis than those held at all other temperatures, while per cent survival was highest at 16°C. Based on these results, we recommend rearing auricularia larvae of P. californicus at a stocking density at or below 0.5 inds/ml, a dietary ration of 40,000 cells/ml, and a temperature of 16°C.     

光色对中华绒螯蟹幼体诱集与仔蟹摄食的影响

为揭示不同发育阶段中华绒螯蟹Eriocheir sinensis对光照颜色的行为反应,探究蟹类颜色视觉的特征,采用自制的试验装置,研究了蓝光(波长446~493 nm)、绿光(波长502~579 nm)、黄光(波长586~600 nm)、红光(波长620~644 nm)、白光(波长440~637 nm)对中华绒螯蟹Ⅱ~Ⅴ期溞状幼体与大眼幼体的诱集效果,以及对仔蟹摄食的影响。结果表明:在室内试验装置中,Ⅱ~Ⅴ期溞状幼体和大眼幼体在蓝光下的分布率最高,极显著高于其他光照组(P0.01),各期幼体在绿光下的分布率也不同程度地高于其他光照组;在室外土池中,采用容积为1 L的捕苗器,在蓝光下捕获大眼幼体的数量最多,为1097尾,极显著高于白光组(253尾)、红光组(121尾)和黄光组(35尾)(P0.01),显著高于绿光组(629尾)(P0.05);24 h内各光色组中仔蟹的昼夜摄食量结果显示,各组仔蟹的日摄食量无显著性差异(P0.05),白天摄食量平均值高于夜晚,但差异并不显著(P0.05)。     

杜仲梦尼夜蛾发育历期及取食行为研究

杜仲梦尼夜蛾是单食性食叶害虫,专性为害杜仲。本研究旨在摸清该害虫的发育及为害规律,为制定防治决策提供依据。通过野外采集越冬蛹,室内羽化并交尾、产卵,对孵化的幼虫采用单头饲养的方法精确测量幼虫各龄期的取食量,同时,观察并记述该虫各虫态的形态特征及其发育历期。结果表明,杜仲梦尼夜蛾越冬代历时213.85d,蛹期172.40d;在寄主植物生长季,其完成一个世代平均需要59.8d,其中卵期4.45d,幼虫期19.7d,蛹期28.85d,成虫期6.8d。幼虫期蜕皮7次,经历8个龄期,幼虫期存活率达98.9%。越冬代除蛹期外其他虫态历期与上述一致。幼虫全期取食,每头幼虫总取食量平均为1.65g新鲜叶片,6、7、8三个龄期幼虫总的取食量占幼虫期取食总量的79.71%。幼虫为害期约为20d,其防治工作应在5龄之前完成。     

Characterization of the bacterial community associated with early‐developmental stages of grass carp (Ctenopharyngodon idella)

Bacterial communities in eggs and larvae of grass carp were analysed. During the early‐developmental stages, grass carp harboured five bacterial phyla, i.e. Proteobacteria, Bacteroidetes, Verrucomicrobia, Planctomycetes and Firmicutes. However, the composition of bacterial communities varied among the different developmental stages. In eggs, the bacterial communities were dominated by Proteobacteria, while in larvae the dominant bacterial community was Bacterioidetes. With the exception of a large proportion (>50%) of uncultured bacteria, Sphingobacterium (14.75%) and Acinetobacter (13.11%) were the most abundant groups in eggs at the fertilization stage (FS). However, Aermonas was the most abundant group, ranging from 40.54% to 61.76% in eggs at the cleavage (CS), blastula (BS), organ differentiation (ODS) and hatching stages (HS). In larvae after first ingestion (OW), Chitinophagaceae (79.41%) formed the predominant bacterial community. Changes in the bacterial community were further confirmed by statistical analysis, which demonstrated significant differences in the bacterial communities of eggs at FS, eggs from CS to HS and OW. However, no significant difference was found in bacterial communities of eggs from CS to HS. Furthermore, the present study revealed that bacteria related to Chitinophagaceae persisted from CS to OW, suggesting that these bacteria form part of the autochthonous microbiota of the fish.     

斜带石斑鱼(♀)×鞍带石斑鱼(♂)杂交子代仔、稚鱼的异速生长

应用实验生态学的方法研究斜带石斑鱼(Epinephelus coioides)(♀)×鞍带石斑鱼(E. lanceolatus)(♂)杂交子代(青龙斑)仔、稚鱼阶段的生长模式。利用Q-Capture Pro 6软件对仔、稚鱼(0~28日龄)的全长、肛前长、体高、头长、眼径、口径、第二背鳍棘、腹鳍棘、胸鳍、臀鳍和尾鳍等11个可量性状进行拍照和测量。研究表明青龙斑全长的生长可分为3个阶段, 不同阶段生长速率存在显著差异(P<0.05)。各功能器官均表现为异速生长。在11个可量性状中, 肛前长为等速生长, 头长和体高的生长由正异速生长分别转变为等速生长和负异速生长; 头部器官(口径和眼径)生长在20 ~22日龄时出现拐点, 拐点后分别转变为等速生长和负异速生长; 运动器官在拐点前均为正异速生长, 除臀鳍外, 其他各鳍的生长均存在不同的拐点。通过对青龙斑仔、稚鱼异速生长的研究, 发现在早期发育过程中, 有关摄食、感觉、运动等功能器官得到优先发育。在人工繁殖苗种的培育中, 可根据青龙斑重要器官发育的优先性, 创造有利的外部环境, 提高苗种的成活率。

     

催青条件对蚕蚁色限性品种产卵质量的影响

蚕卵在不同条件下催青,不同交配组合间存在差异,平均单蛾产卵数以高温干燥♀×高温干燥♂组合>高温干燥♀×自然温湿♂组合>自然温湿♀×自然温湿♂组合>自然温湿♀×高温干燥♂组合。比较分析不同交配组合间的不受精卵率,显示出蚕卵经高温干燥处理后发育而成的雌雄蛾,有降低当代蚕蛾不受精卵率的现象。高温干燥催青条件对后代卵的孵化影响是高温干燥♀×自然温湿♂组合>自然温湿♀×自然温湿♂组合>高温干燥♀×高温干燥♂组合>自然温湿♀×高温干燥♂组合。     

红珠凤蝶小斑亚种幼虫的生物学特性

为合理开发利用红珠凤蝶小斑亚种和有效控制其为害,室内用卵叶马兜铃叶片饲养幼虫,研究了红珠凤蝶小斑亚种幼虫的生活习性、取食量和体重的变化规律。结果表明,幼虫有取食自身蜕和相互残杀的习性。1~3龄幼虫取食量较小,为幼虫总食量的5.23%,5龄幼虫的取食量最大,为幼虫总食量的77.11%。取食速率的变化趋势与取食量相似。幼虫期体重变化呈“S”型。     

绿翅绢野螟幼虫头部感器超微结构观察

为探讨和分析绿翅绢野螟Diaphania angustalis(Snellen)幼虫头部感器的功能及其作用机制,通过扫描电镜对其触角和口器上的感器进行了观察。结果表明:绿翅绢野螟幼虫头式为下口式,头部具有触角、上唇、上颚、下颚和下唇。触角短小,位于幼虫头部侧下方,分3节,其梗节和鞭节分布有4种类型的感器,即毛形感器、短毛感器、锥形感器和栓锥形感器。口器分为上唇、上颚、下颚和下唇4个部分,共具有6种类型感器,分别为毛形感器、刺形感器、指形感器、锥形感器、栓锥形感器和小感觉锥。刺形感器数量较多,分布范围广,口器上各部位均有分布;毛形感器仅分布于上唇;指形感器仅分布于内唇;锥形感器仅分布于下颚;栓锥形感器在下颚和下唇皆有分布;指形感器为内唇所特有。     

管氏肿腿蜂及其带菌室内防治松褐天牛幼虫研究

在室内通过5菌株感染松褐天牛幼虫研究筛选出毒力相对较强菌株Ma789,然后进一步研究了其1.0×10^5-1.0×10^8个/mL不同孢子含量梯度对松褐天牛幼虫的毒力,结果显示其对松褐天牛幼虫的半致死含量为3.2×10^5个/mL;而管氏肿腿蜂对松褐天牛幼虫室内寄生试验表明,随着接蜂量的增加,管氏肿腿蜂对幼虫的寄生死亡率不断提高,当虫蜂比提高到1∶4-1∶5时,管氏肿腿蜂对松褐天牛幼虫的平均校正死亡率达96.7%;每只管氏肿腿蜂携带Ma789约1.0×10^7个孢子时,对老熟松褐天牛幼虫按虫蜂比1∶1、1∶2和1∶3接蜂,寄生感染死亡率分别为56.7%,70%和100%。