菊芋叶总黄酮提取工艺优化及含量动态变化

以菊芋叶为原料,研究了甲醇体积分数、提取温度、提取时间、固液比等因素对菊芋叶总黄酮含量的影响,在单因素试验的基础上,以L9(34)正交试验方法优化总黄酮提取工艺,然后在该工艺条件下研究不同采收时期对菊芋叶总黄酮含量的影响。结果表明:甲醇体积分数、提取温度、提取时间、固液比对菊芋叶总黄酮提取含量均有影响,最佳工艺组合为:用体积分数70%的甲醇,固液比1:30(g/mL),80℃条件下提取2 h,在此条件下,菊芋叶总黄酮含量为7.03%。采收时间对菊芋叶总黄酮含量影响较大,9月份总黄酮含量最高。     

三种微小RNA在意大利蜜蜂工蜂蛹期发育过程中的表达谱及潜在功能

[目的]意大利蜜蜂Apis mellifera ligustica是生产性能优良的西方蜜蜂Apis mellifera亚种.本研究旨在利用分子生物学手段揭示3种微小RNA(microRNA,miRNA) ame-miR-13b,ame-miR-100和ame-miR-bantam调控蛹期变态发育的分子机理.[方法]通过...     

湖北双蝴蝶小孢子发生及雄配子体发育(英文)

首次报道了湖北双蝴蝶小孢子发生和雄配子体发育。主要结果如下:花药四室;药壁发育为双子叶型;绒毡层异型起源,属腺质型绒毡层,药隔处的绒毡层细胞形成类胎座,其余部位的绒毡层细胞仍为一层细胞;花药成熟时,药室内壁纤维状加厚且柱状伸长,表皮细胞减缩退化,纤维状加厚不明显。小孢子母细胞减数分裂为同时型,四分体排列方式主要为四面体形,少数为十字交叉形;成熟花粉多为2-细胞型,偶见3-细胞型,具三萌发孔。     

萝卜-芥蓝杂种F_1代创制及杂种鉴定

以萝卜为母本,以芥蓝为父本,采用人工去雄授粉的方法进行杂交,然后通过胚抢救(embryo rescue)得到F1代植株,并利用RAPD技术对杂种F1代幼苗进行了鉴定.RAPD鉴定结果表明:杂种表现出亲本的特异带或者亲本不具备的新谱带,有的还遗失了亲本的特异带或者共有带.     

萝卜-芥蓝杂种F1代创制及杂种鉴定

以萝卜为母本,以芥蓝为父本,采用人工去雄授粉的方法进行杂交,然后通过胚抢救（embryo rescue）得到F1代植株,并利用RAPD技术对杂种F1代幼苗进行了鉴定。RAPD鉴定结果表明：杂种表现出亲本的特异带或者亲本不具备的新谱带,有的还遗失了亲本的特异带或者共有带。     

濒危植物西康玉兰种子休眠、萌发及贮藏特性

研究了西康玉兰(Magnolia wilsonii)种胚的形态大小,温度、层积、硝酸钾、浸种处理和GA_3对种子休眠及萌发的影响.通过将种子脱水至不同含水量和在两种温度(4℃和一20℃)下贮藏100 d后测其生活力,分析各处理对西康玉兰种子活力的影响.结果表明:西康玉兰种子胚尚未分化完全,需经过低温层积完成生理后熟;低温层积和GA3可打破种子休眠.种子最适萌发温度为25/20℃.由此推测,西康玉兰种子具有形态生理休眠特性.西康玉兰种子当含水量降至5.39%,存活率为53.50%.不同含水量的种子贮藏在-20℃条件下,100 d后种子全部死亡;但在4℃下含水量为10.31%的种子存活力高达76%.因此,西康玉兰种子极可能属于中间性种子,其适宜贮藏环境为4℃下的干藏或湿藏.     

MRSA感染性创面菌群结构分析

目的探究耐甲氧西林金黄色葡萄球菌(MRSA)感染性创面与创面旁菌种组成的差异并寻找可能的有益菌,为从皮肤微生态角度治疗MRSA感染性创面提供理论依据。方法采集湖南省人民医院MRSA感染性创面及创面旁的皮肤样本,其中创面部位样本22份为D组,创面旁样本11份为N组,提取样本DNA,采用高通量测序技术对16S rRNA基因V3-V4区测序并进行生物信息学分析。结果根据Alpha多样性分析,D组的Chao1指数、Ace指数和Shannon指数明显低于N组(Z=62, P=0.023 8；Z=66, P=0.035 9；Z=30, P=0.000 2),而Simpson指数明显高于N组(Z=211, P=0.000 3)。Beta多样性分析显示2组皮肤菌群组成具有差异,表明分组合理(R=0.584 3、0.467 3, P=0.001 0)。D组葡萄球菌属(Staphylococcus)及韦荣球菌属(Veillonella)丰度显著性升高(Z=213, P=0.000 5；Z=48.5, P=0.004 8),其他常驻菌群均下降。N组的乳杆菌属(Lactobacillus)相对丰度均值较D组高(Z=38, P=0.000 8)。结论MRSA感染性创面的菌群结构较创面旁组具有一定变化,Lactobacillus为皮肤有益菌,可能对创面的恢复有益。     

Ocean acidification and warming will lower coral reef resilience

Ocean warming and acidification from increasing levels of atmospheric CO₂ represent major global threats to coral reefs, and are in many regions exacerbated by local‐scale disturbances such as overfishing and nutrient enrichment. Our understanding of global threats and local‐scale disturbances on reefs is growing, but their relative contribution to reef resilience and vulnerability in the future is unclear. Here, we analyse quantitatively how different combinations of CO₂ and fishing pressure on herbivores will affect the ecological resilience of a simplified benthic reef community, as defined by its capacity to maintain and recover to coral‐dominated states. We use a dynamic community model integrated with the growth and mortality responses for branching corals (Acropora) and fleshy macroalgae (Lobophora). We operationalize the resilience framework by parameterizing the response function for coral growth (calcification) by ocean acidification and warming, coral bleaching and mortality by warming, macroalgal mortality by herbivore grazing and macroalgal growth via nutrient loading. The model was run for changes in sea surface temperature and water chemistry predicted by the rise in atmospheric CO₂ projected from the IPCC's fossil‐fuel intensive A1FI scenario during this century. Results demonstrated that severe acidification and warming alone can lower reef resilience (via impairment of coral growth and increased coral mortality) even under high grazing intensity and low nutrients. Further, the threshold at which herbivore overfishing (reduced grazing) leads to a coral–algal phase shift was lowered by acidification and warming. These analyses support two important conclusions: Firstly, reefs already subjected to herbivore overfishing and nutrification are likely to be more vulnerable to increasing CO₂. Secondly, under CO₂ regimes above 450–500 ppm, management of local‐scale disturbances will become critical to keeping reefs within an Acropora‐rich domain.