“多谋”与“善断”

在新的课程标准要求下的生物教学实践过程中，学生对概念、原理的领会，不能只停留在表面，要从字里行间，众多的现象中，抓住要点，深入本质，立足教材，多角度、多方位地分析和思考，才能去伪存真，由表及里地作出准确判断，得出正确结论。     

几种影响黑松针叶束离体培养再生植株的因子（简报）

以5年生黑松针叶束为外植体,经离体培养形成小植株。返幼的短针时束(3～10mm)芽诱导率最高。芽诱导和生长的最佳培养基分别为;1/2GD-1+BA0.5mg/L(单位下同)+NAA0.05+LH200和1/2GD-1+BA0.225+NAA0.001+GA_30.5。嫩梢生根率为1％,根数1～3条。从针叶束接种到小植株形成,约需200～240天。     

籼稻体细胞胚胎发生的组织学及细胞学研究

以成熟种子为外植体,在离体培养中研究了体细胞胚胎发生,组织学研究表明,愈伤组织是由成熟种子盾片的表皮吸收细胞首先发生的,随后从愈伤组织分化出胚状体。象水稻合子胚的结构一样,体细胞胚状体主要由盾片,胚芽稍及胚根组成,在胚状体内可以观察到不同发育时期的原胚,包括大量的单一的胚性细胞、二细胞、四细胞及分化程度不同的原胚以及一些畸形胚状体,从本实验可以初步认为由籼稻体细胞培养而获得的胚状体在结构上也有象合子胚一样的基本结构,并且是单细胞起源的。     

植物细胞在离体培养条件下的决定问题

“决定”(Determination)这一术语来自动物胚胎发育生物学,意指胚胎某一区域的组织或细胞只能向某一特定方向分化的发育状态。决定与否以及决定的程度必须用离体培养或异位移植的方法来测定。“决定”作为发育生物学上的一种现象,同样存在于高等植物中,如茎生长点的成花决定和     

中国桑寄生科植物资料(二)

我国桑寄生科(狭义的)共有8属,约49种、7变种。现续报道大苞鞘花属Elytranthe Blume 1个新记录种,离瓣寄生属Helixanthera Lour.产于云南1个新记录种及其描述和西藏2个种,桑寄生属Loranthus Jacq.2个种,梨果寄生属Scurrula Linn.3个种和钝果寄生属Taxillus Van Tiegh.4个种的分布区和标本引证,以及一些种类的寄生,异名和错误文献等。 桑寄生科植物对木本经济植物具有危害性,作者在云南、广西和广东野外工作时,注意到在局部地区,“桑寄生类”对栽培的油茶林、普洱茶林、石梓林、云南油杉林、栎林,柿树及风景区的庭园树的危害情况,已成为主要的植物病害。     

在被小泡参与突触前后膜特化增厚的形态学研究

Our object was to characterize the morphological changes of coated vesicles and synaptic membranes during synaptogenesis. Neurons from spinal cords of fetal mice were established as isolated cells in primary culture. After a few days in vitro, the neurons extended their neurites and started their interaction. At timed intervals thereafter, cultures were fixed for electron microscopic observation. Coated vesicles were prominent in the neuronal cytoplasm at the time of synaptogenesis (about 7-10 days in vitro). Similar vesicles were seen in continuity with some cisternae in the Golgi regions and there was an increase in number during the synaptogenic period. Indeed it is not established whether the coated vesicles were exocytotic or pinocytotic in nature, but the cisternae which were in continuity with coated vesicles could be labelled by glucose-6-phosphatase (G6Pase) but not by thiamine pyrophosphatase (TPPase). Such vesicles were also seen in continuity with the neuronal plasmalemma near the closest contact site and contributed their undercoating to pre- and postsynaptic densities. The formation of bilateral membrane specialization was described as being structurally similar to synaptic active zones and appeared to be the first definitive sign of synapseformation. It has been suggested that the synaptic dense material may derive wholly or in part from the exocytic coated vesicles which apparently budding off from endoplasmic reticulum cisternae. This incorporation could provide the mechanism for confining specific characteristics of neuronal membrane to the synaptic region.     

GA_3和BR对离体苎麻叶片中过氧化氢酶和过氧化物酶的影响及其与超氧物歧化酶的关系(简报)

经1．0mg·L-1GA3和0．1mg·L-1BR分别处理后的离体苎麻叶圆片中,过氧化物酶和过氧化氢酶活性都有明显增加。过氧化物酶的最大增加值出现在12h;过氧化氢酶与超氧物歧化酶同步,最大增加值出现时间都在处理后36h。0．2mmol·L-1H202处理的过氧化氢酶和超氧物歧化酶活性都增加;3．0mg·L-1NaN3处理的超氧物歧化酶活性明显增加;19．5mg·L-1KCN处理的过氧化氢酶活性则明显下降。