我国西沙群岛白蚁调查及新种描述

一、前言 1974年5、6月间,广东省昆虫研究所,派员到我国西沙群岛(宣德群岛和永乐群岛所属的主要八个岛屿)进行动物与昆虫区系的调查。就中在永兴岛上采有白蚁标本14号,经初步整理有木白蚁科(Kalotermitidae)的截头堆砂白蚁[Cryptotermes domesticus(Haviland)]和鼻白蚁科(Rhinotermitidae)的西沙原鼻白蚁(Prorhinotermes xishaensis sp. nov.)两种。并见到家白蚁[Coptotermes formosanus (Shiraki)]的被害状,但未采到家白蚁标本,1975年3、4月间高道容同志在西沙群岛珊瑚岛采到大量家白蚁标本及被害状,始得肯定其分布。     

我国森林害虫“松毛虫”综合防治的实践及展望

我国森林害虫的种类很多,其中以松毛虫类为害最严重。松毛虫的种类多,分布广,繁殖力强,猖獗时能食尽松针,引起大面积松林死亡。严重影响绿化成果的巩固及林产品产量和质量的提高。松毛虫体上的毒毛,触人肌肤引起肿痛,也影响人民的健康。 松毛虫猖獗成灾,在我国历史上早有记载,但历代反动统治者,从未重视这一问题,听之任之视为天灾,解放后党和政府重视森林资源的保护和发展,为此从中央到地方建立     

我国柑桔新害虫——柑桔地粉蚧记述及防治

国内从未报道过的一种地粉蚧——柑桔地粉蚧 Geococcus citrinus Kuwana 1960—1965 年在福建初次发现。它属于同翅目,蚧总科,粉蚧科。当年我们在资料交流时把它暂名为柑桔根粉蚧,果区群众称之为“小白虫”。这种国内柑桔上的新害虫在福建的一些果区严重发生为害,是引致柑桔树衰退的一个主要原因,群众迫切要求防治。根据生产上的需要,我们时柑桔地粉蚧的发生和为害情况进行过初步的考查,同时进行了药剂防治试验。本文除了介绍这两方面的工作结果外,并就分布、奇主和形态特征作简要的记述。     

昆虫线粒体发生的生化和亚显微结构的研究

线粒体在细胞中的发生目前有各种观点的争论,其理论意义涉及到真核细胞的起源和进化、染色体和线粒体两个遗传体系之间的相互关系以及生物膜合成和组装机理等。我们对处于分化中的昆虫胸肌线粒体的观察结果是:(1)对粘虫变态期的呼吸和细胞色素氧化酶活力测定表明蛹期第8天的组织形成阶段是胸肌细胞分化和其线粒体发生的开始。电镜观察表明,线粒体形成分两个阶段:由颗粒结构(可能是酶蛋白与脂的复合体)装配成膜片和膜泡;由膜泡分化出内嵴,进而发育为线粒体。(2)QO₂值,P/O比和ATP酶活力的出现与膜结构的分化发育相平行。α-甘油磷酸氧化酶系统比谷氨酸氧化酶系统装配早;电子传递酶系比磷酸化酶系装配早。(3)蝗虫胸肌分化过程的电镜观察证明;先形成内膜小泡(直径约0.1微米左右),后形成外膜,组成简单线粒体;后者进一步分化发育为成熟线粒体。(4)QO₂值,P/O比和ATP酶活力与膜结构分化发育相平行。ATP酶的出现与能量转涣功能呈平行关系。膜形成早期和“幼稚”线粒体阶段,ATP酶尚未装配。(5)综合上述结果:线粒体膜由非膜结构逐步组装形成,线粒体内膜的各酶系组装次序不同步,线粒体DNA控制合成的膜蛋白在膜结构形成中似乎起核心和骨架作用;线粒体总组装过程在不同细胞中表现为多种途径和方式。     

Evacuolation and enucleation of mesophyll protoplasts in self-generating percoll gradients

Mesophyll protoplasts from Brassica oleracea, B. napus, Nicotiana tobaccum and Solanum tuberosum were isolated and subjected to uttracentrifugation at 65000g for 30 min in percoll solutions containing various strengths of salt and osmotic stabilizing agents. After centrifugation, the self-generated percoll gradients were evaluated for their effectiveness in protoplast evacuolation and enucleation. The vacuoles, cell debris, evacuolated protoplasts and enucleated protoplasts were separated. Factors that affected evacuolation and enucleation in the percoll gradients were described. Mesophyll protoplasts produced by epidermis peeling and short enzyme incubation periods were more easily evacuolated and enucleated than those produced by leaf-slicing and long incubation periods. Lower centrifugal force at 25000g for 80 min was also successful in evacuolating and enucleating the mesophyll protoplasts. A green band that contained nearly pure evacuolated protoplasts, of which 45% were enucleated protoplasts, was obtained from the self-generated percoll gradient. Rhodamine 123 staining of mitochondria indicated that the evacuolated protoplasts were metabolically active and were capable of regenerating the vacuole and cell wall. Cell divisions were also observed when the evacuolated protoplasts were cultured.     

Glucose and δ-Aminolevulinic Acid Stimulate the Dark Chlorophyll Synthesis of Rice Seedlings

This research was to examine if rice (Oryza sativa L.), a monocotyledon of angiosperm, was able to synthesize chlorophyll (Chl) in complete darkness. Five-cm-tall etiolated seedlings of rice were used as starting materials and treated with or without various concentrations of glucose and/or δ-aminolevulinic acid (ALA) in the dark. Leaves harvested at the indicated time were determined for their contents of Chl, protoporphyrin Ⅸ(Proto), Mg-protoporphyrin Ⅸ(Mg-Proto) and protochlorophyllide (Pchlide). The mole percentage of porphyrin was calculated. The Chl content in the etiolated rice seedlings slightly increased from about 2.5 μg/g to 7.5 μg/g within 12 d in the dark, but the total Chl of dark-grown rice increased from 0.36 μg/g to 3.6 μg/g. While the mole percentages of Proto, Mg-Proto and Pchlide in the dark-grown seedlings without any treatment were about 65%, 27.5% and 7.5% at the beginning, respectively, those in the light-grown seedlings were about 42.5%, 35% and 22.5%, respectively. The mole percentage of porphyrin of etiolated seedlings resumed its normal ratio within 2 d after treatment with glucose. While the Chl content of etiolated seedlings grown in culture solution with 3% and 6% glucose increased 2.5 and 4.0 folds, respectively, those with 3% and 6% glucose and 1 mmol/L ALA increased 22 and 24 folds, respectively. It is concluded that angiosperm might be able to synthesize a small amount of Chl in complete darkness, that either glucose or ALA could stimulate dark Chl synthesis in angiosperm, and that a combination of glucose and ALA exhibited an additional effect. It is still unknown and remains to be further explored what is the mechanism of the effect of glucose and ALA on the Chl synthesis of rice in the dark. Key words: angiosperm; rice; dark chlorophyll synthesis; glucose; δ-aminolevulinic acid; protoporphyrin Ⅸ; Mg-protoporphyrin Ⅸ; protochlorophyllide     

豚鼠眶外肌中快肌与慢肌纤维的小终板电流

豚鼠眶外肌中有两类不同电活动模式的肌纤维。一类纤维有动作电位,小终板电位时程较短并且较一致;另一类纤维不能产生动作电位,小终板电位时程较长而且多变。用电泳注射普胺天蓝分别标记这两类纤维各6条,并结合胆碱酯酶染色,结果表明,前一类肌纤维都是只有一个神经肌肉接头的快纤维;而另一类肌纤维都是有多个接头的慢纤维。根据双微电极电庄箱位实验结果,计算了上述决、慢肌纤维小终板电流下降相时间常数τ及其电压系数A。实验表明:(1)在静息电位附近,慢肌纤维小终板电流的τ值大于快肌纤维的;(2)慢肌纤维的A值比快肌纤维的小的多,即τ值较少随膜电位变化。本文对上述不同曾加以讨论。