异色瓢虫与隐斑瓢虫的区别及其色斑型和横脊的频率

异色瓢虫Harmonia axyridis(Pallas)和隐斑瓢虫H.yedoensis(Takizawa)是亲缘关系很近的姐妹种,在中国(北京到南岭,西至甘肃南部和西藏东部)、日本(北海道以南)和南韩等地同域分布,常常在松树等植物上共存。长期以来,隐斑瓢虫被认为是异色瓢虫的一个异名。有时从外形上很难区分这2种瓢虫,因此对于依据野外数据,分析异色瓢虫色斑型和鞘翅横脊的发生频率及小进化会产生一些错误。本文从没有隐斑瓢虫分布的东北地区的材料及其他数据,报道异色瓢虫的色斑型及鞘翅横脊发生频率。异色瓢虫的花斑型在我国东部地区(从东北至广东北部,西至甘肃和云南)发生率很低,而在新疆西北部发生率较高。鞘翅横脊的发生率从东北佳木斯的98.85%降低到云南大理的78.26%。本文列出了区分这2种瓢虫的形态特征及自然分布。如果鞘翅具横脊,则属于异色瓢虫,但如果标本来自2种瓢虫的共存区,鞘翅没有横脊,鞘翅的斑纹呈花斑型、四窗型或二窗型,则很难从外部形态上对它们进行鉴定。但这2种瓢虫的幼虫很容易区分。本文还提供了2种瓢虫的雄性外生殖器形态图、幼虫和成虫。     

异色瓢虫不同色斑型成虫的耐寒性研究

【目的】研究异色瓢虫Harmonia axyridi不同色斑型成虫的耐寒能力,以明确其色斑型比例所呈现的季节性变化的适应意义。【方法】本文测定了异色瓢虫实验种群和自然种群不同色斑型成虫的过冷却点(Supercooling point,SCP)及低温存活率。【结果】同一发育温度下异色瓢虫实验种群不同色斑型成虫的SCP和低温存活率均没有显著性差异(P>0.05),但是低温暴露中饲养在25℃下成虫的存活率下降更为剧烈。异色瓢虫自然种群黑底型与黄底型成虫的SCP呈现出明显的季节性变化,其SCP在7月份最高,分别为﹣8.2℃和﹣7.5℃;在1月份达到最低,分别为﹣16.8℃和﹣18.2℃。越冬开始(11月)黑底型成虫的SCP低于黄底型成虫的,整个越冬期间黄底型成虫的SCP一直低于黑底型成虫的,但是异色瓢虫黑底型与黄底型越冬成虫的低温存活率却没有显著性差异(P>0.05)。【结论】越冬期间异色瓢虫黄底型成虫的SCP低于黑底型的,这样可以通过体液过冷却的方式来避免结冰造成的伤害,以增强其越冬种群的耐寒能力,这也可能是越冬期间异色瓢虫黄底型成虫数量显著上升的一个原因。     

不同色斑型异色瓢虫的同工酶比较

采用聚丙烯酰胺凝胶垂直板型电泳技术,对15种不同色斑型异色瓢虫Harmonia axyridis(Pallas)的酯酶同工酶(EST)、过氧化氢同工酶(CAT)、淀粉酶(α-AMY)和苹果酸脱氢酶(MDH)进行比较研究。结果表明:15份材料共获得25个同工酶位点,其中多态性位点20个,多态位点百分率为80%;根据酶带结果,利用NTSYSpc2·10e软件进行Jaccard相似系数分析,15种不同色斑型异色瓢虫遗传相似度为0·44~0·96,平均遗传距离为0·42;通过UPGMA聚类分析,在相似系数0·65处,15份瓢虫材料分为2大类群;主成分分析结果表明,显现变种、拟月斑变型和眼斑变型3种斑型瓢虫是异色瓢虫遗传变异的主线。     

异色瓢虫(Harmonia axyridis)鞘翅色斑二个新等位基因和嵌镶显性遗传学说的再证实

异色瓢虫是一个鞘翅色斑表现多态的亚洲物种。但在苏联西伯利亚中西部阿尔泰地区群体几乎单一地由黑底小黄斑的花斑型axyridis(S~x)所组成,在我国东北黑龙江几乎全为黄色或黄底带有不同数目小黑点的黄底型Succinea(ss)所组成,由北向南黄底型的百分比逐渐减小,增添了黑底大黄斑类型。因此,常见的有三型:由浅色的黄底型和深色的四窗型Spectabilis(S~s)和二窗型conspicua(S~c)所组成,越向南深色类型越趋增多。鞘翅色斑各型的频率,在其广大的分布区内有着地理性的变化,但各局部地区亦有相对稳定的一定的频率,标志着该局部地区的群体的特征(Tan,1932;Dobzhansky 1951)。除上述空间的变化外,也存在着季节性的变化等(Mayr,1963;Tan,1948)。群体中除上述三种基本类型外,尚有罕见类型,各罕见类型也以一定的低频率而出现,     

不同色斑型异色瓢虫COⅠ和COⅡ基因序列系统进化分析

利用线粒体COⅠ和COⅡ基因序列分析法,研究13种色斑型异色瓢虫Harmonia axyridis Pallas的系统分化,计算核苷酸的使用频率,并构建分子系统树,以便更好地探索异色瓢虫色斑变异的规律。结果表明,在用于分析的COⅠ基因和COⅡ基因的序列中,共有31个变异位点,29个简约信息位点,A+T平均约占71.2%,大部分碱基改变为颠换。13种不同色斑型异色瓢虫的遗传距离为0.0021～0.0328,平均相似系数为0.0193。分别采用邻接法(NJ)、最大简约法(MP)、最小进化法(ME)构建系统发育树。分子系统树显示:各类群间遗传分化很小,鞘翅颜色相同的瓢虫均已较高的置信值聚在一起;双月斑变型和显明变种亲缘关系最近,重名变种为原始类群,分化较早,与其它12种不同色斑异色瓢虫亲缘关系较远。     

两种豆科作物田捕食性瓢虫群落研究

利用生物多样性研究方法, 对通辽市科尔沁区两种豆科作物田开花期捕食性瓢虫群落进行研究。结果表明: 两种捕食性瓢虫群落的物种组成和发生个体数量上存在差异, 具体为大豆田分布捕食性瓢虫8属10种, 以异色瓢虫Harmonia axyridis (Pallas)数量最多(122头); 苜蓿田分布5属8种, 以多异瓢虫Hippodamia variegata (Goeze)数量最多(68头)。两个捕食性瓢虫群落相似性较高, 差异性较大的捕食性瓢虫物种其个体数量均明显多于其它物种。色斑型研究显示异色瓢虫具27种变型, 多异瓢虫有8种, 龟纹瓢虫Propylea japonica (Thunberg) 有6种变型; 且大豆田捕食性瓢虫色斑变型(共35种)明显多于苜蓿田(共16种)。     

三种蔷薇科果树小绿叶蝉及捕食性天敌种群动态的比较

对3种果树小绿叶蝉及其天敌数量进行t检验得出,樱桃园与梨园之间,小绿叶蝉、异色瓢虫、锥腹肖蛸差异显著、三突花蟹蛛差异极显著,均是樱桃园多于梨园;樱桃园与杏园之间,三突花蟹蛛、草间小黑蛛差异显著,异色瓢虫、锥腹肖蛸差异基本显著,均是樱桃园多于杏园,小绿叶蝉差异基本显著,杏园多于樱桃园;梨园与杏园之间,草间小黑蛛和小绿叶蝉均差异显著,杏园多于梨园。采用灰色系统分析方法研究樱桃小绿叶蝉数量与其天敌个体数量关联度,结果是,关联度较高的天敌依次是锥腹肖蛸、草间小黑蛛、八斑球腹蛛和中华草蛉,与理想优势种天敌数量关联度较高的天敌依次是三突花蟹蛛、异色瓢虫、草间小黑蛛和中华草蛉;利用生态位分析方法分析的结果是,与小绿叶蝉时间生态位和空间生态位重叠指数较大的天敌依次是异色瓢虫、草间小黑蛛、三突花蟹蛛和锥腹肖蛸;与小绿叶蝉两种生态位相似性比例指数较大的天敌依次是异色瓢虫、三突花蟹蛛、草间小黑蛛和锥腹肖蛸。综合排序分析,前4位的天敌依次是异色瓢虫、草间小黑蛛、三突花蟹蛛和锥腹肖蛸。     

黑带食蚜蝇体色变异的研究

通过对黑带食蚜蝇Episyrphus balteatus(De Geer)体色变异的研究,发现黑带食蚜蝇存在深色型和浅色型2种基本形式,体色变异具有明显的季节性,深色型个体出现在温度较低的秋季及早春,浅色型个体发生在温度较高的春夏季节;在腹部色斑方面,深色型和浅色型个体中均存在变异,可划分为8种类型,腹部色斑的变异在浅色型个体中较为丰富,腹部不同体节背板上色斑的变异程度不同;黑带食蚜蝇在体型大小方面同样存在差异,这些变异的多态性可能是食蚜蝇系统学研究中异名产生的一个重要原因。因此,食蚜蝇类群的个体体色变异在系统学研究中是一个必须特别注意的问题。     

异色瓢虫成虫对麦二叉蚜的捕食作用模型

通过异色瓢虫雌,雄成虫对麦二叉蚜捕食作用研究,得出：1．异色瓢虫雌、雄成虫对麦二叉蚜捕食作用的功能反应均是HollingⅡ型反应;2．异色瓢虫捕食麦二叉蚜时,同等数量的异色瓢虫雌雄混合的干扰作用大于同一性别成虫间的干扰作用;3．异色瓢虫雌、雄成虫均喜好捕食低龄若蚜．     

茶园4种半翅目主要害虫与其捕食性天敌的关系

为了科学施药,合理利用和保护天敌进行假眼小绿叶蝉、通草粉虱、黑刺粉虱和茶蚜的综合防治,用灰色系统分析方法,生态位分析方法和空间格局聚集强度指标分析方法对潜山县茶园4种半翅目主要害虫与其捕食性天敌在数量、时间、空间格局等方面进行分析,评判出害虫的主要天敌,与假眼小绿叶蝉数量上跟随关系密切的天敌是三突花蟹蛛、斑管巢蛛、鞍型花蟹蛛、茶色新圆蛛和八点球腹蛛;时间上是三突花蟹蛛、斑管巢蛛、鞍型花蟹蛛、八点球腹蛛和茶色新圆蛛;空间上是三突花蟹蛛、斑管巢蛛、草间小黑蛛、八点球腹蛛和茶色新圆蛛;把与假眼小绿叶蝉在数、时、空方面参数大小的序号积加,和最小的即是第一位天敌,其综合排序得出假眼小绿叶蝉的主要捕食性天敌依次是三突花蟹蛛、斑管巢蛛、八点球腹蛛、茶色新圆蛛和鞍型花蟹蛛。与通草粉虱数量上跟随关系密切的天敌是锥腹肖蛸、日本球腹蛛、草间小黑蛛、龟纹瓢虫和八点球腹蛛;时间上是龟纹瓢虫、锥腹肖蛸、草间小黑蛛、八点球腹蛛和日本球腹蛛;空间上是八点球腹蛛、草间小黑蛛、龟纹瓢虫、异色瓢虫和三突花蟹蛛;把与通草粉虱在数、时、空方面参数大小的序号积加,综合排序得出通草粉虱的是龟纹瓢虫、草间小黑蛛、八点球腹蛛、锥腹肖蛸和异色瓢虫。与黑刺粉虱数量上跟随关系密切的天敌是草间小黑蛛、锥腹肖蛸、八点球腹蛛、异色瓢虫和鞍型花蟹蛛;时间上是草间小黑蛛、八点球腹蛛、锥腹肖蛸、异色瓢虫和斑管巢蛛;空间上是八点球腹蛛、草间小黑蛛、异色瓢虫、锥腹肖蛸和龟纹瓢虫;把与黑刺粉虱在数、时、空方面参数大小的序号积加,综合排序得出黑刺粉虱的是八点球腹蛛、草间小黑蛛、锥腹肖蛸、异色瓢虫和斑管巢蛛。与茶蚜数量上跟随关系密切的天敌是异色瓢虫、日本球腹蛛、草间小黑蛛、鞍型花蟹蛛和八点球腹蛛;时间上是日本球腹蛛、草间小黑蛛、鞍型花蟹蛛和茶色新圆蛛;空间上是异色瓢虫、草间小黑蛛、、八点球腹蛛、茶色新圆蛛和鞍型花蟹蛛;把与茶蚜在数、时、空方面参数大小的序号积加,综合排序得出茶蚜的是异色瓢虫、日本球腹蛛、草间小黑蛛、鞍型花蟹蛛和茶色新圆蛛。4种害虫种群聚集均数λ均大于2,其聚集是害虫本身原因造成的,天敌的种群聚集均数λ均小于2,其聚集是环境因子所致。     

Curcuminoids as inhibitors of thioredoxin reductase: A receptor based pharmacophore study with distance mapping of the active site

Curcumin is the yellow pigment of turmeric that interacts irreversibly forming an adduct with thioredoxin reductase (TrxR), an enzyme responsible for redox control of cell and defence against oxidative stress. Docking at both the active sites of TrxR was performed to compare the potency of three naturally occurring curcuminoids, namely curcumin, demethoxy curcumin and bis-demethoxy curcumin. Results show that active sites of TrxR occur at the junction of E and F chains. Volume and area of both cavities is predicted. It has been concluded by distance mapping of the most active conformations that Se atom of catalytic residue SeCYS498, is at a distance of 3.56 from C13 of demethoxy curcumin at the E chain active site, whereas C13 carbon atom forms adduct with Se atom of SeCys 498. We report that at least one methoxy group in curcuminoids is necessary for interation with catalytic residues of thioredoxin. Pharmacophore of both active sites of the TrxR receptor for curcumin and demethoxy curcumin molecules has been drawn and proposed for design and synthesis of most probable potent antiproliferative synthetic drugs.     

A Unique Protease Cleavage Site Predicted in the Spike Protein of the Novel Pneumonia Coronavirus (2019-nCoV) Potentially Related to Viral Transmissibility

正Dear Editor,In December 2019, a novel human coronavirus caused an epidemic of severe pneumonia(Coronavirus Disease 2019,COVID-19) in Wuhan, Hubei, China(Wu et al. 2020; Zhu et al. 2020). So far, this virus has spread to all areas of China and even to other countries. The epidemic has caused 67,102 confirmed infections with 1526 fatal cases     

Comparative morphology of the carpel in the Liliaceae: Hewardieae, Petrosavieae, and Tricyrteae

The young pistils in the melanthioid tribes, Hewardieae, Petrosavieae and Tricyrteae, are uniformly tricarpellate and syncarpous. They lack raphide idioblasts. All are multiovulate, with bitegmic ovules. The Petrosavieae are marked by the presence of septal glands and incomplete syncarpy. Tepals and stamens adhere to the ovary in the Hewardieae and the Petrosavieae but not in the Tricyrteae. Two vascular bundles occur in the stamens of the Hewartlieae and Tricyrtis latifolia. Ventral bundles in the upper part of the ovary of the Hewardieae are continuous with compound septal bundles and placental bundles in the lower part. Putative ventral bundles occur in the alternate position in the Tricyrteae and putative placental bundles in the opposite. position in the Petrosavieae. The dichtomously branched stigma in each carpel of the Tricyrteae is supplied by a bifurcated dorsal bundle.     

鸡传染性法氏囊病病毒研究进展

传染性法氏囊病(Infection bursal disease, IBD)是由鸡传染性法氏囊病毒(Infectious bursal disease virus, IBDV)引起的鸡和火鸡的一种高度接触性传染病,给世界各国的禽养殖业带来了巨大损失.自IBDV发现至今新的变异株不断出现,分子结构的改变导致病毒致病力的改变及宿主对疫苗应答的改变,使得传统的疫苗已不能控制其流行,因此各国学者对其基因组结构和功能进行了广泛深入的研究,并积极研制新型有效的疫苗以达到防治的目的.     

Development of a Novel Reverse Transcription Loop-Mediated Isothermal Amplification Method for Rapid Detection of SARS-CoV-2

In conclusion, the novel visual RT-LAMP assay is a simple, rapid, and sensitive approach for detection of SARS-CoV-2, and it is ready for application in primary care and community hospitals or health care centers, and even patients' own houses in response to the current SARS-CoV-2 epidemic because the assay does not require sophisticated equipment and skilled personnel. Furthermore, it is also ready to be used in fields for screening samples from wild animals and environments to facilitate the identification of potential intermediate hosts that mediate the cross-species transmission of SARS-CoV-2 from bats to humans.     

Perinatal Vertical Transmission of Chikungunya Virus in Ruili,a Town on the Border between China and Myanmar

正Dear Editor,Chikungunya virus (CHIKV), an arbovirus in the family of Togaviridae, genus Alphavirus, is transmitted by the A.aegyptii or A. albopictus mosquito, and causes disease in humans characterized by fever, rash, and arthralgia (Silva and Dermody 2017; Suhrbier 2019). It was first reported in 1953 in Tanzania, and caused only a few outbreaks and sporadic cases in Africa and Asia in last century. However, in the epidemic in 2004, CHIKV acquired mutations that conferred enhanced transmission by the A. albopictus mosquito(Schuffenecker et al. 2006). Since then, it has successively caused outbreaks in Africa, the Indian Ocean, South East Asia, the South America, and Europe (Zeller et al. 2016).