杂交水稻干种子内存在α-淀粉酶

水稻种子萌发过程中的α-淀粉酶由盾片上皮细胞合成而运入胚乳(Okamoto等1979,1980),或由种胚分泌的赤霉素(GA_3)的触发作用在糊粉层中诱导形成(Murakami 1966,Ogawa 1966,Tangka等1970)。但迄今尚未见谷类作物干胚乳中预存有α-淀粉酶的报道(Daussant等1983,Tanaka等     

刺激家兔腹部迷走神经外周端降压效应中枢机制的研究

应用电解损毁和脑室内注射药物的方法研究了刺激家兔腹部迷走神经外周端所致降压效应的中枢机制。结果表明:1.电刺激延脑闩部尾侧1.5—2mm、中线旁开0.25mm、深1—2mm 处主要引起降压反应。2.电解损毁该部位可以使刺激腹部迷走神经外周端所引起的降压效应显著减弱(n=20,P<0.001),但对刺激减压神经所致降压反应无影响。3.在延脑闩部水平电解损毁减压神经纤维在孤束核的主要投射区可以使刺激减压神经所致降压反应显著减弱,而对刺激腹部迷走神经外周端所致降压反应无影响。4.第四脑室注射5,6-双羟色胺的动物较之注射人工脑脊液的动物颈、胸髓5-羟色胺含量明显降低、动物动脉压增高、心率明显增快、刺激减压神经所致降压反应未见减弱,而刺激腹部迷走神经外周端所致降压反应却明显减小。因此,我们认为家兔腹部迷走神经外周端所致降压效应依赖于延脑闩下部的中缝隐核及连合核等结构,而与减压神经的投射部位无关。延脑中缝核至脊髓的下行性5-HT能神经纤维抑制脊髓交感节前神经元的活动,是这个降压效应的中枢机制之一。     

刺激隐神经C类纤维诱发体感皮层电反应(平均诱发电位)

当猫的隐神经A类纤维单独兴奋时,可引起同侧脊髓背表面电位 A-SSP(潜伏期 2.6±0.4ms)和对侧体感皮层诱发电位 A-CEP。A-CEP由早成分(潜伏期 9.6±1 1ms)和晚成分(203.0±10.gms)组成。当 C类纤维选择性传入时,出现特异的 C-CEP(潜伏期 134.4±25.9ms)和C-SSP(115.8±15.6ms)。C-CEP的幅值较A-CEP 小,并随C类纤维传入的数量而改变。C-CEP的最大幅值位于后乙状回一定部位,多为负或正-负电位,在皮层深层其相位倒转。与A-CEP相比,C-CEP的中枢延搁时间较长,跟随频率较低,对镇痛药较敏感。表明C-CEP不同于A-CEP,它是由C类传入所引起的,是在体感皮层内产生的。当A类和C类纤维同时传入时,只有A-CEP和A-SSP出现,而不出现C-CEP和C-SSP。在阻断电流逐渐增强过程中,C-CEP较C-SSP后出现;而在撤销阻断过程中,则C-CEP较C-SSP先消失。提示C类传入在中枢可能被A类传入所抑制,这种抑制可以发生在脊髓和脊上水平,后者可能更强。     

大劣按蚊吸血活动与交配受精的关系

大劣按蚊Anophelos dirus是我国及东南亚地区的重要传疟媒介。研究表明成蚊羽化后,在未喂血的情况下,可有较高的交配受精率。在同一蚊笼,吸血机会完全相同的条件下,大蚊笼受精雌蚊吸血率为59.88%,未受精雌蚊的吸血率为35.38%;小蚊笼受精雌蚊的吸血率为74.13%,未受精雌蚊吸血率仅为43.56%。正常交配雌蚊的吸血率为49.71%,未进行交配的处女雌蚊吸血率为28.42%。同为正常交配蚊群,喂血组雌蚊受精率55.85%,不喂血组的受精率为44.51%。初步认为大劣按蚊的吸血活动与交配受精有一定的关系。     

夜蛾科新种记述

本文记述夜蛾科3新种,分别采自四川峨眉山和湖北神农架。新种的正模标本保存子中国科学院动物研究所,副模标本保存于湖北省农业科学院植物保护研究所。 1.大斑明夜蛾Sphragifera magniplag新种 翅展38毫米。胸部背面及颈板白色,布有零星黑点,下胸与足淡褐色,足腿节与胫节杂有黑色;腹部褐色,腹面杂有黑色;前翅白色,翅基部及中区布有黑褐色点,一红棕色斜     

常量喷布植物乳油对大田害虫杀虫活性类型分析

1％稗Echinochlca crusgalli Beauv乳油(稗籽净油:甲苯:SOS=1:0.01:0.005)对大田棉蚜Aphis gossypii Glover充分显示较强的触杀活性。其触杀效果与丁硫威(Marshal)一致,并能抑制黄瓜系统花叶病(cmv,mmv)的发生。1980—83年,我们筛选、提取了部分植物性物质,并利用这些提取物在田间水稻和蔬菜害虫中进行一系列试验,产生了一定击倒、触杀和拒避效果。     

图夜蛾属一新种(鳞翅目:夜蛾科)

本文记述图夜蛾属一新种。新种的模式标本保存于中国科学院动物研究所。 隐图夜蛾Eugraphe obsoleta新种(图1) 翅展29毫米。头部淡褐色,下唇须第1、2节外侧大部褐黑色,第3节淡黄色,头顶褐色,雄蛾触角双栉形,栉齿短,有纤毛,颈板与翅基片淡褐色,胸部背面黑褐色,足暗灰褐色;腹部暗褐色,节间赭黄色;前翅淡赭黄色,中室色较暗,各横线不明显,环纹大,近圆形,     

Pacemaker Properties of Completely Isolated Neurones in <Emphasis Type="Italic">Aplysia californica</Emphasis>

SINGLE-CELL pacemaker activity is interesting because of its function in temporal organization and information processing in the nervous system. Many invertebrate neurones are regularly and autonomously active^1,2. Although the pacemaker rhythm probably originates within the recorded neurone, it is not clear whether it originates in the axonal tree or in the cell soma. Alving³ approached this question by studying pacemaker activity in the soma of Aplysia nerve cells, after ligaturing the axonal stem with fine sutures. The study described here presents evidence that nerve cell somata which are completely dissociated from all surrounding tissue and with or without axons, are able to maintain regular autorhythmic activity for periods of more than 24 h. The method of complete isolation of cells represents some progress over Alving's method because it is easier to accomplish, has a larger yield of viable neurones and allows longer recording periods.     

四川跳之一新属新种

本文记述跳(虫甲)亚科(Alticinae,Chrysomelidae)的新属Omeisphaera,系以新种O.anticata为模式种,产于四川峨眉山。模式标本保存在中国科学院北京动物研究所。 峨眉球跳(虫甲)Omeisphaera新属 本新属与Sphaeroderma Stephen及Argopus Fischer两属最接近,外形更酷似Argopus属的种类,但唇基正常(图3),不若该属种类之向前叉开而分为两叶。它的主要区别特征在于后胸腹板的前部,即介于中足基节之间的部分显著隆起,向前突出,与前胸腹板相遇,遮盖了中胸腹板(图4);前突的端末钝圆,不具边框。在Sphaeroderma、Argopus等属,后胸腹板前部并不隆起,端末具边框,与中胸腹板嵌合,处于同一水平。     

Carbohydrate Metabolism in the Narcissus Leaf

Carbohydrate contents of both the photosynthetic and the storageorgans of Narcissus tazetta L. were determined at four stagesin their development under both ‘natural’ growingconditions and under conditions of varying light intensities. Starch was abundantly stored in all the storage organs, particularlyin the bases of the photosynthetic organs under high light intensityand also at the second dormant stage. However, its level remainedrelatively stable in the green part of the foliage leaf andthe scape at different stages and appeared not to be affectedby light except at very high intensity. It was found in boththe bundle sheaths and guard cells. Sucrose, which is the first sugar of photosynthesis, was continuouslyexported from the green parts of the blade and the scape totheir bases where it was also stored. In the dark the sucroselevel became low in the green blade and the green scape butit rose with increase of light intensity. The hexose level was very low at the dormant stage in all organsexamined but rose as they matured and exceeded that of sucrosein the green organs except in high light intensity. Hexose isformed presumably as a result of sucrose hydrolysis and is constantlylost, presumably through respiration. At senescence sugar disappeared almost completely from all theorgans, while nearly 10 per cent of residual dry weight of starchremained in the dead tissues. The interrelationship betweenthe carbohydrates and their movement in the leaf is discussed.