环境因子对新疆B型烟粉虱发育与繁殖的影响

研究了不同温度、寄主、光照时间对新疆地区烟粉虱发育与繁殖的影响.结果表明,不同温度处理下新疆B型烟粉虱的产卵量差异显著,在25℃恒温下,B型烟粉虱在烟草和番茄上产卵量都最高,分别为152粒/雌和182粒/雌,且成虫寿命最长.在昼夜24 h光照下新疆B型烟粉虱产卵量最高.在不同寄主上产卵量也有显著差异,在卡莫蒂尼上产卵量最高,为147粒/雌.在不同温度处理下,温度越高,新疆B型烟粉虱发育历期越短.35℃条件不能发育到成虫.在25℃温度下粉虱的存活率最高.     

种间竞争对烟粉虱和桃蚜生长发育及繁殖力的影响

【目的】研究烟粉虱Bemisia tabaci与桃蚜Myzus persicae的种间竞争。【方法】在(26±1)℃的条件下,设置了1∶1、1∶5和1∶10的种间竞争比例,调查烟粉虱和桃蚜的发育历期、存活率、成虫寿命及产卵/仔量情况。【结果】种间竞争延长了烟粉虱1~2龄若虫发育所需的时间,但对整个若虫期的发育速度影响不大。烟粉虱∶桃蚜为1∶1、1∶5时对烟粉虱若虫的存活率影响较小,但缩短了烟粉虱雌成虫的寿命、降低了其产卵量;而烟粉虱∶桃蚜为1∶10明显降低了烟粉虱若虫期的存活率,延长了烟粉虱雌成虫的寿命,提高了其后代繁殖量。种间竞争明显延长了桃蚜若虫期的发育时间,降低了若虫期的存活率。相对而言,桃蚜∶烟粉虱为1∶1、1∶5时,桃蚜成虫的寿命有所缩短,但对其单雌产仔量影响较小;桃蚜∶烟粉虱为1∶10显著延长了桃蚜雌成虫寿命的同时,降低了其单雌产仔量。【结论】生态位重叠的昆虫的种间竞争对昆虫种群数量影响很大,有时甚至会发生种间的竞争取代。     

B型烟粉虱在不同类型棉花上的生态适应性

研究了不同类型棉花(彩棉、Bt棉和低酚棉)对B型烟粉虱的生长发育的影响。结果表明,B型烟粉虱在低酚棉上的成虫数量和产卵量显著高于其他两个品种,分别占总虫数的46.1%和总卵量的47.7%。彩棉上的虫量和产卵量最少,分别为23.4%和23.1%。B型烟粉虱在不同类型棉花上的适生性存在显著差异,其中在低酚棉上若虫历期最短,存活率最高,而在Bt棉和彩棉上的若虫历期较长,存活率较低,生态适应性较低。B型烟粉虱在低酚棉上的成虫寿命最长,雌成虫在低酚棉和Bt棉上的产卵量显著高于在彩棉上的产卵量。     

不同品系抗刺吸式转基因棉对Q型烟粉虱生长发育的影响

测定了Q型烟粉虱(Bemisia tabaci)在3个不同品系的抗刺吸式口器害虫转基因棉花与其亲本棉花品种上的体型差异、发育历期、成活率、成虫寿命、产卵量和生命参数,以分析不同抗刺吸式转基因棉花品系对Q型烟粉虱的抗虫效果.结果表明,Q型烟粉虱的体型、发育历期、存活率以及成虫寿命等多个生长发育参数在转基因棉花品系与对应亲本间无显著差异;但Q型烟粉虱在转基因棉品系上的产卵量和种群净增值率明显低于其对应亲本棉,种群加倍时间高于其亲本棉,表明检测的3个转基因抗虫棉品系都对Q型烟粉虱有抗性.烟粉虱成虫单雌产卵量、种群净增值率和种群加倍时间等3个生命参数指标为评价其它抗刺吸式口器转基因棉花对Q型烟粉虱的抗虫效果提供参考指标.     

不同寄主植物对B型烟粉虱生长发育的影响

在26℃条件下测定了五种寄主植物对B型烟粉虱个体发育、种群存活率、成虫寿命和生育力的影响。寄主植物不同，烟粉虱幼期存活率、成虫寿命和生育力差异较明显，而对其生长发育影响不大。比较种群趋势指数，甘薯为最适寄主，芥蓝次之，棉花最差。     

温度对B型烟粉虱试验种群的影响

在不同恒温条件下观察了B型烟粉虱的发育、存活和繁殖情况,求出了发育起点温度和有效积温,计算了种群增长指数。结果表明:20℃发育历期为30.5天,而32℃下为14.9天。B型烟粉虱发育的最适温度为26℃,低于20℃或高于32℃皆使发育变缓。不同温度下寿命和单雌产卵量有显著差异。20℃烟粉虱成虫寿命和产卵量均为32℃时的两倍多。内禀增长力在29℃时最高。数据显示26℃是烟粉虱种群发育和繁殖的最适温度。     

捕食不同虫态烟粉虱对小黑瓢虫生长发育的影响

分别提供烟粉虱卵、若虫(含拟蛹)、成虫3种虫态供小黑瓢虫捕食,饲喂结果表明:小黑瓢虫最喜食烟粉虱卵,其次为烟粉虱若虫(含拟蛹),最不喜食烟粉虱成虫。捕食不同虫态猎物对小黑瓢虫生长发育存在一定的影响。烟粉虱卵饲喂的小黑瓢虫发育速度快(幼虫至成虫羽化为19.18d)、存活率高(幼虫至成虫羽化为78.57%)、成虫的繁殖力强(平均每雌产卵131.25粒)、种群内禀增长率大(rm=0.0724),明显优于其他2种虫态,最有利于人工繁殖小黑瓢虫。     

不同园林植物对Cv型烟粉虱发育和繁殖的影响

研究了CV型烟粉虱在扶桑、一品红、芙蓉和变叶木上的发育、存活和繁殖情况〔实验室温度26(±1)℃,相对湿度75%～90%,L∶D 14∶10〕。烟粉虱从卵发育到成虫的存活率以在扶桑上的最高、为41.58%,一品红上的最低、为27.15%;发育时间在芙蓉上最短、为26.43 d,一品红上最长、为41.63 d,差异显著;扶桑、一品红、芙蓉和变叶木上的平均单雌产卵量分别为29.76,36.56,48.85和66.80粒/雌;成虫的寿命在一品红上最长、平均为21.36 d,芙蓉上最短,为11.90 d;内禀增长率rm在芙蓉上的最大、为0.0668,一品红上最小、为0.0344。综合比较4种不同寄主植物,芙蓉是烟粉虱种群生长发育和繁殖最适宜的寄主。     

烟草品种对Q型烟粉虱生物学参数的影响

为明确烟草不同品种对Q型烟粉虱(Bemisia tabaci)生物学参数影响的差异,筛选出抗Q型烟粉虱烟草品种。在室内温度(26±1)℃,湿度70%~80%,光照L:D=14:10条件下,研究6个烟草品种对Q型烟粉虱生长发育和繁殖的影响。结果表明,Q型烟粉虱在6种烟草品种上发育历期没有明显差异,而其存活率、成虫寿命、单雌产卵量及生命参数差异显著。用生命参数表综合评价,G28、G140、K326和NC95是利于Q型烟粉虱的种群生长发育及繁殖的品种,为易感虫品种,其中K326最敏感,云烟85和革新三号是抗性较强的品种。     

短时高温暴露对B型烟粉虱和温室白粉虱存活以及生殖适应性的影响

 【目的】研究短时高温暴露对B型烟粉虱和温室白粉虱成虫存活和生殖适应性影响的差异。【方法】将B型烟粉虱和温室白粉虱的成虫在不同温度（37℃、39℃、41℃、43℃、45℃）下暴露1 h后比较两种粉虱存活、产卵量、后代存活情况的变化以及两者的差异。【结果】随着暴露温度的升高,B型烟粉虱成虫的存活率从99.1%下降到42.6%,温室白粉虱成虫的存活率从95.0%下降到13.5%。两种粉虱雌雄虫在45℃高温暴露1 h后,B型烟粉虱成虫的寿命超过10 d,而温室白粉虱成虫存活的时间不足24 h,存在显著差异。高温暴露对B型烟粉虱成虫的产卵量没有显著影响,但后代的存活率随着暴露温度的升高由70.7%下降到25.1%。温室白粉虱成虫在37～43℃暴露1 h后雌虫产卵量由62.4粒下降到1.5粒,45℃暴露1 h后停止了产卵活动;导致B型烟粉虱和温室白粉虱成虫后代50%和90%个体死亡的温度分别相差1.6℃和4.1℃。【结论】B型烟粉虱成虫的耐热性高于温室白粉虱,高温对B型烟粉虱成虫存活和生殖适应性的影响要小于温室白粉虱,这有利于B型烟粉虱种群在夏季高温季节的发生。B型烟粉虱和温室白粉虱对高温适应性存在差异尤其是高温对两者生殖适应性的影响是导致它们种群季节动态格局和分布存在差异的重要原因。     

Pathogenesis of a local graft versus host reaction: immunogenicity of circulating host leukocytes

A local invasive-destructive reaction typical of that seen in allograft rejection occurs when Lewis rat spleen cells are inoculated under the capsule of Lewis kidney freshly grafted into F(1) hybrid hosts. Thus the donor lymphoid cells can be immunogenically stimulated by circulating host leukocytes and the interaction of these two cell populations results in nonspecific damage to kidney parenchyma. The results indicate that passenger leukocytes in organ allografts may be important immunogenic agents.     

Volatile chemical cues guide host location and host selection by parasitic plants

The importance of plant volatiles in mediating interactions between plant species is much debated. Here, we demonstrate that the parasitic plant Cuscuta pentagona (dodder) uses volatile cues for host location. Cuscuta pentagona seedlings exhibit directed growth toward nearby tomato plants (Lycopersicon esculentum) and toward extracted tomato-plant volatiles presented in the absence of other cues. Impatiens (Impatiens wallerana) and wheat plants (Triticum aestivum) also elicit directed growth. Moreover, seedlings can distinguish tomato and wheat volatiles and preferentially grow toward the former. Several individual compounds from tomato and wheat elicit directed growth by C. pentagona, whereas one compound from wheat is repellent. These findings provide compelling evidence that volatiles mediate important ecological interactions among plant species.     

辣椒青枯病的防治

近年来,我地莱农种植的辣椒刚进入盛花结果期(一般在5月上旬)就出现辣椒植株枯萎,有时叶片脱落,果实一部分像火烤一样枯白,然后整株枯死,发病迟可收1～2层辣椒,发病早且严重的田块基本绝收。菜农把它当作辣椒疫病治疗,效果不佳,其实,这是辣椒青枯病,一般辣椒栽培书中没有介绍这种病害,此病害在辣椒生长期内时有发生。     

Viral infection and host defense

Double-stranded RNA, made as an intermediary substance in the replication of most, if not all, viruses, may play a much more important role in the pathogenesis and the recovery from virus infections than has hitherto been suspected. Apparently, dsRNA is used by both the challenge virus and the host cell in an attempt to gain "molecular control." Double-stranded RNA exerts a set of effects, which may be well balanced, not only at the level of the individual cell but also at the complex assemblage of these cells termed the organism (Fig. 1). In the cell, interferon synthesis is triggered, although interferon mRNA translation may not occur if dsRNA shuts off protein synthesis too quickly. In the whole organism, the disease severity will depend on how certain toxic reactions evoked by infection (such as cell necrosis and fever) are counterbalanced by an increase in the host defense mechanisms (for example, immune responsiveness and interferon production). Many aspects of the response, relating to either progress of, or recovery from, the disease, can be explained on the basis of a dsRNA. In addition to drawing attention to the biodynamic role of dsRNA, our hypothesis suggests specific experimental vectors designed to enhance our information on the molecular basis of the morbid process which occurs with viral infection. Finally, we suggest that, although the dsRNA molecule may be viewed as a rather simple unit structure, the opportunity for further diversity in the biological activity of a given dsRNA molecule always exists. Namely, each deviation from a perfectly double-helical arrangement introduces the possibility for emphasizing one biological reactivity at the expense of another. This latter structure-activity property may partially account for the extreme apparent diversity, commonly encountered, in the presentations of virologic illness. Appendix note added in proof. Subsequent to submission of this text, we have found that the potent mitogen effect of dsRNA for lymphocytes (murine and human) is also exquisitively sensitive to the fidelity in base pairing of the input polymer pair (59). For example, infrequent "loops" (one nucleotide per 20 base pairs) in an otherwise perfectly helical rI(n) (.) rC(n) molecule [for example, rI(n) (.) r(C(19,)U)(n)] strongly changes its mitogenic properties. This observation, which supports our thesis that a "fine structure" term can be developed for other reactions triggered by dsRNA's in biological systems, emphasizes that diverse biological effects may be encountered with an ostensibly uniform family of dsRNA's.     

微胶囊化昆虫病毒在宿主体内的动态增殖研究

为进一步了解微胶囊化斜纹夜蛾核型多角体病毒(Spodoptera litura nuclear polyhedrosis virus,SINPV)在宿主体内的侵染过程,以明胶/羧甲基纤维素(Carboxymethylcellulose,CMC)为壁材,茶多酚为固化剂,斜纹夜蛾核型多角体病毒为芯材的病毒微胶囊,通过建立实...