Depolymerization of cortical microtubules is not a primary cause of chilling injury in corn (Zea mays L. cv Black Mexican Sweet) suspension culture cells

Cold-induced depolymerization of cortical microtubules were examined in suspension culture cells of corn (Zea mays L. cv Black Mexican Sweet) at various stages of chilling. In an attempt to determine whether microtubule depolymerization contributes to chilling injury, experiments were carried out with and without abscisic acid (ABA) pretreatment, since ABA reduces the severity of chilling injury in these cells. Microtubule depolymerization was detectable after 1 h at 4°C and became more extensive as the chilling was prolonged. There was little chilling injury after 1 d at 4°C in either ABA-treated or non-ABA-treated cells. After 3 d at 4°C, there was about 26% injury for ABA-treated and 40% injury for non-ABA-treated cells, as evaluated by 2,3,5-triphenyl-tetrazolium chloride reduction and by regrowth. After 1d at 4°C, less than 10% of cells retained full arrays of microtubules in both ABA-treated and non-ABA-treated cells, the remainder having either partial arrays or no microtubules. After 3d at 4°C, about 90% of cells showed complete or almost complete depolymerization of microtubules in both ABA-treated and non-ABA-treated cells. ABA did not stabilize the cortical microtubules against cold-induced depolymerization. In about 66% of ABA-treated cells and 57% of non-ABA-treated cells that had been held at 4°C for 3d, repolymerization of cortical microtubules occurred after 3h at 28°C. These results argue against the hypothesis that depolymerization of cortical microtubules is a primary cause of chilling injury.     

油松毛虫的光周期反应:温度和营养对临界光周的影响

油松毛虫Dendrolimus tabulaeformis Tsai et Liu的临界光周值,在适温区内随温度的下降而增加.不同季节和不同生长阶段的油松针叶,即营养质量不同的针叶,对油松毛虫幼虫的生长、发育和存活影响明显,从而影响着油松毛虫的光周期反应.这些结果,为油松毛虫的世代发生及种群动态的预测提供了一定的依据.     

温度对家白蚁的生存和活动的影响

家白蚁 Coptotermes formosanus Shiraki 的生存、行为和取食活动与温度密切相关。探索温度对家白蚁的生存以及行为、取食诸活动的影响,对于研究其生态学和防治学,都具有重要意义。广东省昆虫研究所对此曾进行过许多有益的研究,并作过一些有价值的报道。笔者于1986—1987年,对此问题作了系统的试验,得到一些新的结果,报道如下。     

中国寄生云杉的顶裂盘菌及其无性阶段

本文报道了寄生在云杉上的中国新记录种顶裂盘菌(Lophophacidium hyperboreumLagerb.);首次发现了这个种的无性型座壳梭孢属(Apostrasseria sp.),证实了融雪前病株针叶上有表生的菌丝和小菌核;查清了它是新疆云杉林中的广布种,引致云杉雪枯病;发现了新分布区,地理分布范围在75°—94°E,37°40′—49°N;发现了新寄主,多土的西伯利亚云杉(Picea obovata Ledeb.)和引进的青海云杉(P.crassifolia Kom.)、川西云杉(P.balfourianaRehd.et Wils.)。     

用飞机喷洒有机磷超低容量制剂防治蝗虫

本文总结了1975—1980年在新疆巴里坤草原等地区进行的笼内药剂品种筛选试验、地面和飞机超低容量喷雾治蝗试验。结果表明:马拉松、马拉松与敌敌畏混剂、乐果、稻丰散和乙基稻丰散5种飞机超低容量制剂均可取代六六六粉剂防治各种蝗虫。每亩喷洒量为100—150克;每亩有效药量:马拉松、马拉松与敌敌畏混剂为25—45克;乐果为20—30克;稻丰散和乙基稻丰散为25—40克,蝗虫死亡率在90%以上。 使用飞机超低容量制剂治蝗具有防效好,功效高,成本低和环境污染少等优点。目前已在新疆、内蒙、青海和辽宁等省(自治区)大面积应用。累计防治面积达一千一百万亩,深受牧区群众欢迎。     

山林原白蚁栖居地及各品级记述

瑞典白蚁专家Holmgren记载了亚洲的两种原白蚁:山林原白蚁Hodotermopsis sjstedt Holmgren(1911)和日本原白蚁Hodotermopsis japonicus Holmgren(1912)。经蔡邦华教授(1980)进一步研究认为是山林原白蚁的同物异名。作者根据浙江(龙泉)、山林原白蚁的栖居地及其巢内的诸品级发生情况,于1975—1980在龙泉进行了逐年调查。现将调查结果报道如下:     

黑翅土白蚁巢外天敌的调查

诸暨县林种站小溪寺林区是浙江省板栗良种基地,有3,000多亩山地。据诸暨县白蚁防治站1976年调查,已有90％板栗树根部被白蚁筑上泥被泥线,树皮被啃食后,生长停滞,甚至枯死。繁殖保护天敌是综合防治的重要内容;为此,我们于1978年进行了初步调查。 调查日期为分飞期前(5月21日—26日)和分飞期(5月27—6月24日),地点为小溪寺林区板栗林,水库堤坝和次生松林。     

银纹夜蛾的核型多角体病毒病

银纹夜蛾(Plusia agnata Staudinger)幼虫是大豆主要食叶害虫。在泰安地区,历年约占大豆害虫总发生量的70％以上;除大豆外,还为害甘蓝、白菜、棉麻等作物。 1979年6月,发现室内饲养的银纹夜蛾幼虫有倒挂死亡的虫体,经鉴定是一种核型多角体病毒病,现将其实验结果报道如下。