七星瓢虫和异色瓢虫四变种成虫对茶蚜蜜露的搜索行为和蜜露的组分分析

采用培养皿 ,1承接茶蚜自然分泌蜜露 ;2收集蜜露浓缩后点于培养皿中心。逐头释放瓢虫于分别盛有这 2类蜜露的培养皿中心进行生物测定 ,两个试验均证明 :1蜜露强烈地吸引七星瓢虫和异色瓢虫 ,随着蜜露浓度呈梯度地增大 ,搜寻时间极显著地延长 ( P<0 .0 1 ) ;2蜜露可激发瓢虫的搜索行为由广域搜索型转换为地域集中搜索型。前 0～ 5s局限在较小范围内不断地转向 ,即搜索速度小 ,转动角度大。七星瓢虫和异色瓢虫显明变种最敏感 ,搜索和滞留时间也最长。用高效液相色谱定性定量地分析出蜜露中有茶氨酸等 1 3种氨基酸和蔗糖等 7种糖分。     

七星瓢虫和异色瓢虫四变种成虫对茶蚜蜜露的搜索行为和蜜露的组分 …

采用培养皿,①承接茶蚜自然分泌蜜露;②惧蜜露浓缩后点于培养皿中心。逐头释放瓢虫于分别胃这２类蜜露的培养皿中心进行生物测定,两个试验均证明：①蜜露强烈地吸引七星瓢虫和异色瓢虫,随着蜜露浓度呈梯并地增大,搜寻时间极显著地延长（Ｐ〈０．０１）;②蜜露可激发瓢虫的搜索行为由广域搜索型转换为地域集中搜索型。前０￣５ｓ局限在较小范围内不断地转向,即搜索速度小,转动角度大。七星瓢虫和异色瓢虫 变种最敏感,搜索和     

不同生境异色瓢虫对茶梢互利素和蚜虫利它素EAG和行为反应

触角电位(EAG)研究和选择性行为反应表明茶梢受茶蚜(Toxoptera aurantti Boyer)为害后能释放引诱异色瓢虫LLeis axyridis(Pallas)]的互利素,茶蚜、萝卜蚜Lipaphis erystmi(Kaltenbach)体表和茶蚜蜜露中含有吸引异色瓢虫的利它素,其中的少数特异性组分引诱活性较强.源于茶园、桑园和菜园的互利素或利它素对各自生境中的异色瓢虫更具刺激性,显示了生境特定性.EAG剂量反应表明茶园中的显明变种比显现变种稍敏感,这可能是由于前者触角上的化感器数量较多所致.     

不同生境异色瓢虫对茶梢互利素和蚜虫昨它素EAG和行为反应

触角电位（EAG）研究和选择性行为反应表明茶梢受茶蚜（Toxoptera aurantii Boyer）为害后能释放引诱导色瓢虫[Leis axyridis(Pallas)]的互利素,茶蚜、萝卜蚜Lipaphis erysimi(Kaltenbach）体表和茶蚜蜜露中含有吸引异色瓢虫的利它素,其中的少数特异性组分引诱活性较强。源于茶园、桑园和菜园的互利素或利它素对各自生境中的异色瓢虫更具刺激性,显示了生镜特定性。EAG剂量反应表量茶园中的显明变种比显现变种稍敏感,这可能是由于前者触角上的化感器数量较多所致。     

天敌体内玉米蚜的CoⅡ标记检测

以玉米蚜Rhopalosiphum maidis Fitch及玉米田的捕食性天敌为研究对象,筛选1对特异扩增玉米蚜细胞色素氧化酶Ⅱ(COⅡ)基因序列片段的引物。种特异性检验表明,该引物只对玉米蚜基因组DNA具有扩增效果,对与其同域发生的其他种类不具扩增作用;室内以该引物检测喂食单头玉米蚜的异色瓢虫Harmonia axyridis(Pallas)成虫和大草蛉Chrysopa pallens(Rambur)成虫腹内靶标食物的衰变情况,结果表明,异色瓢虫成虫和大草蛉成虫阳性比率的半衰期分别为喂食后2·814和2·441h;对玉米田间捕食性天敌的检测结果表明,在所检测的6类群13种捕食性天敌中,大灰食蚜蝇幼虫、草蛉幼虫、异色瓢虫成虫和幼虫、龟纹瓢虫成虫和幼虫对玉米蚜的捕食作用检出率较高,大于40%。     

异色瓢虫4变种成虫对茶和茶蚜气味行为反应

用Y形嗅觉仪测定了异色瓢虫4个变种成虫对茶蚜利它素的行为反应,结果表明,供给茶蚜、甘蓝蚜和萝卜蚜的两两组合,茶蚜+蚜害茶梢和正常茶梢,蚜害茶梢和正常茶梢,天敌分别选择茶蚜、茶蚜+蚜害茶梢或蚜害茶梢(P<0.05);以8～9种质量梯度的茶蚜+蚜害茶梢、蚜害茶梢和茶蚜做味源,瓢虫对味源趋向率与味源质量呈Logistic曲线关系(P<0.01),其中二斑变型、显现变种和十九斑变种对茶蚜的趋向率与蚜数呈左偏的单峰曲线(P<0.01);茶蚜体表乙醚或正己烷漂洗物也有引诱力,以显明变种最敏感.     

秋末苏南茶园昆虫的群落组成及其趋色性

苏南地区名茶荟萃,而虫害历来较为严重。秋末选丹阳市一片无公害茶园,使用纯白、桃红、墨绿、果绿、湖蓝、天蓝、素馨黄、芽绿、土黄、桔黄、大红和紫色12种粘性色板诱虫。结果表明:① 4日内捕获7目42科85种30455头昆虫,其中优势类群是同翅目、膜翅目和双翅目,三者个体数分别占总个体数的86.5%、8.8%和2.5%。②主要害虫是假眼小绿叶蝉和茶蚜,分别占总个体数的15%和71.5%。③ 捕获的中华蜜蜂占总个体数8.2%。④捕获天敌昆虫1034头,其中,瓢虫类32头,占3.1%,主要种类是异色瓢虫和黄斑盘瓢虫;草蛉类582头,占56.3%,包括中华草蛉、大草蛉和丽草蛉;伞裙追寄蝇和蚕饰腹寄蝇等5种寄生蝇类111头,占10.7%;门氏食蚜蝇和黑带食蚜蝇等7种食蚜蝇类110头,占10.6%;螟蛉瘤姬蜂和花胸姬蜂等5种姬蜂类、茶尺蠖绒茧蜂和单白绵绒茧蜂等7种茧蜂类个体数分别占3.9%和9.4%。⑤ 芽绿、素馨黄和桔黄色板显著地引诱假眼小绿叶蝉和茶蚜;芽绿、素馨黄色板显著地引诱姬蜂和茧蜂;芽绿、土黄和果绿色板明显地引诱草蛉类;果绿、天蓝和紫色色板引诱较多的蝇类和蚊类等双翅目昆虫;素馨黄引诱的各类昆虫种数最多;纯白板上各类昆虫的多样性指数最大,表明其对许多昆虫都有引诱效应。秋末时节查明即将越冬的害虫和天敌昆虫种类、数量和益害比、以及优势种害虫和优势种天敌数量,探明多种色彩引诱益、害虫的差异,对于有效实施无公害封园防治,以压低越冬基数有重要意义。     

阿维菌素对苹果绣线菊蚜的防治作用及对果园天敌的影响

以1．8％阿维菌素乳油为代表品种,开展了阿维菌素对苹果树绣线菊蚜Aphis citricola田间防治效果试验。结果表明,1．8％阿维菌素乳油1000～3000倍液药后2d、7d、14d对绣线菊蚜的防治效果为64．9％-87．6％。此外,研究了阿维菌素乳油对果园捕食性天敌幼虫种群的影响。田间调查结果表明,施药14d后药剂处理区食蚜蝇Chrysopa septempunctata种群难以恢复,七星瓢虫Epistrophc baltcata种群恢复至喷药前的65％以上,大草蛉Coccinella septempunctate种群基本恢复正常;室内实验结果与田间基本相同,对食蚜蝇影响最大,大草蛉影响最小。但枝条喷药后,在太阳光下放置4h后接虫,则天敌幼虫的死亡率均有明显下降。     

球孢白僵菌对桃蚜及其两种捕食性天敌的影响

从自然感病的温室桃蚜上分离到一株球孢白僵菌Bb21,测定了该菌株对桃蚜的致病性及其对两种捕食性天敌的影响.结果表明:Bb21菌株对桃蚜的致病力强,LD5o为97孢子·mm-2,95％置信区间为45～191孢子·mm-2;对草蛉2龄幼虫有较弱的致病性,LD50为1089孢子·mm-2,是桃蚜的11.2倍;对异色瓢虫致病性极小,高浓度处理(5×108孢子·mL-1)的平均感染率仅为l3％.该菌株低浓度处理对两种捕食性天敌的发育历期和生殖力均无显著影响,但高浓度处理(5×108孢子·mL-1)使异色瓢虫的幼虫期平均缩短1.4d,羽化率降低33％,产卵量减少14％,使普通草蛉的幼虫期平均缩短0.7d,羽化率降低24％,产卵量减少11％.该菌株对桃蚜的半致死剂量远低于对两种捕食性天敌的半致死剂量,并且在防治桃蚜使用浓度下对两种捕食性天敌成虫羽化率和繁殖力的影响极小,可作为温室桃蚜的生物控制因子在有害生物综合治理中应用.     

茶足柄瘤蚜茧蜂对苜蓿蚜的寄生功能反应

在室内(25±1℃,L:D=16:8光周期,RH=40%～60%)条件下,研究了茶足柄瘤蚜茧蜂Lysiphlebus testaceipes(Cresson)对苜蓿蚜Aphis craccivora(Koch)若蚜的寄生功能反应。结果表明:苜蓿蚜的龄期对茶足柄瘤蚜茧蜂的寄生作用有很大影响,用功能反应HollingⅡ模型模拟,其模拟方程为Na=1.118 N/(1+0.0184 N)。通过该方程可明确单头雌成蜂在24 h内最多寄生60.60头苜蓿蚜,其寄生1头苜蓿蚜所需时间为0.396 h。在5个温度梯度下,茶足柄瘤蚜茧蜂对苜蓿蚜的寄生功能反应均符合HollingⅡ模型,但不同温度下的功能反应参数有明显的差异。此外茶足柄瘤蚜茧蜂自身密度对寄生有一定的干扰作用,其干扰作用通过Hassell-Varley模型拟合,方程为a=0.0621P-0.3062,表明茶足柄瘤蚜茧蜂雌蜂的发现域随着自身密度的增加而逐渐变小,寄生蜂雌蜂个体间的相互干扰效应降低了寄生效能。     

Recent advances in the study of Kaposi's sarcoma-associated herpesvirus replication and pathogenesis

It has now been over twenty years since a novel herpesviral genome was identified in Kaposi's sarcoma biopsies. Since then, the cumulative research effort by molecular biologists, virologists, clinicians, and epidemiologists alike has led to the extensive characterization of this tumor virus, Kaposi's sarcoma-associated herpesvirus(KSHV; also known as human herpesvirus 8(HHV-8)), and its associated diseases. Here we review the current knowledge of KSHV biology and pathogenesis, with a particular emphasis on new and exciting advances in the field of epigenetics. We also discuss the development and practicality of various cell culture and animal model systems to study KSHV replication and pathogenesis.     

The structure, reproduction and taxonomy of Vidalia and Osmundaria (Rhodophyta, Rhodomelaceae)

Comprises species occurring mostly in subtidal habitats in tropical, subtropical and warm-temperate areas of the world. An analysis of the type species, V. spiralis (Sonder) Lamouroux ex J. Agardh, a species from Australia, establishes basic characters for distinguishing species in the genus. These characters are (1) branching patterns of thalli, (2) flat blades that may be spiralled on their axis, (3) width of the blade, (4) primary or secondary derivation of sterile and fertile branchlets and (5) position of sterile and fertile branchlets on the thalli. Application of the latter two characters provides an important basic method for separation of species into three major groups. Osmundaria , a genus known only in southern Australia, was studied in relation to Vidalia , and its separation from the Vidalia assemblage is not accepted. Species of Vidalia therefore are transferred to the older genus name, Osmundaria. Two new species, Osmundaria papenfussii and Osmundaria oliveae are described from Natal. Confusion in the usage of the epithet, Vidalia fimbriala Brown ex Turner has been clarified, and Vidalia gregaria Falkenberg, described as an epiphyte on Osmundaria pro/ifera Lamouroux, is revealed to be young branches of the host, Osmundaria prolifera.     

New or rare chromosome counts in Artemisia L. (Asteraceae, Anthemideae) and related genera from Kazakhstan

Fifteen chromosome counts of six Artemisia taxa and one species of each of the genera Brachanthemum, Hippolytia, Kaschgaria, Lepidolopsis and Turaniphytum are reported from Kazakhstan. Three of them are new reports, two are not consistent with previous counts and the remainder are confirmations of very scarce (one to four) earlier records. All the populations studied have the same basic chromosome number, x = 9, with ploidy levels ranging from 2x to 6x. Some correlations between ploidy level, morphological characters and distribution are noted.     

肝癌中HBV和HCV基因和抗原的分布及意义

采用原位分子杂交方法检测HCV RNA及HBV X基因;采用免疫组织化学方法研究HCV核心抗原,非结构区C33c抗原及HBxAg在肝细胞肝癌中的定位及分布.结果表明(1)HCV RNA、HBV X基因在肝细胞肝癌组织检出率分别为40%(55/136)和82%(112/136).HCV RNA定位于癌细胞的胞浆内,阳性细胞呈散在、灶状及弥漫分布三种形式;HBV X基因在肝癌细胞中的分布呈胞浆型、核型及核浆型,阳性细胞也呈上述三种分布形式;(2)HCV C33c抗原、核心抗原在肝细胞肝癌中的阳性率为81%(133/164)及86%(141/164).C33c抗原定位于癌细胞及肝细胞的胞浆内;核心抗原既定位于癌细胞核中,又可定位于胞浆中.C33c抗原阳性细胞以灶状分布为主;而核心抗原阳性细     

Selection with two alleles and complete dominance

For a plant selection model with frequency-independent viabilities, fertilities and selfing rates, it is shown that apart from global fixation, for certain parameter combinations a protected polymorphism and facultative fixation (either allele may become fixed according to initial frequencies) may both occur. Facultative fixation requires different selling rates for the dominant and recessive type. Protection of the polymorphism requires resource allocation for male and female function. In this connection the problem of purely genetically caused population extinction is discussed.
For general frequency dependence and regular segregation, the chances for establishment of a completely recessive gene are compared to those of a completely dominant gene. It is proven that the process of establishment of the recessive gene, despite a fitness advantage, may be considerably endangered by drift effects if random mating prevails. The recessive gene may reach the same effectivity in establishment as a dominant gene, only if the recessive homozygote mates exclusively with its own type during the period of establishment.