Bemerkungen zur Variabilität vonSaxifraga marginata

Saxifraga marginata Sternb. is divided into three subspecies:S. m. subsp.marginata, S. m. subsp.bubakii (Rohlena)Chrtek etSoják,S. m. subsp.karadzicensis (Degen etKo?anin)Chrtek etSoják (environments of Skopje, Macedonia).     

正丁酸钠对人胃腺癌细胞染色体数目和DNA含量的影响

培养的人胃腺癌MGc 80-3细胞经过正丁酸钠处理7天后,生长抑制率达50.7%,约有90%的细胞形态发生分化,其超微结构亦有显著改变。而且,在染色体数目上,超二倍体细胞由对照组的78%增加到实验组的96%,超三倍体和超四倍体细胞则分别从6%和14%下降至2%。同时应用~3H-TdR放射自显影和福尔根细胞光度法测定未标记细胞(G_1期)DNA含量,结果显示实验组比对照组降低了。而且在实验组的同一制片中,未分化细胞DNA含量平均为超六倍体值(DI=3.67和3.56),其中90%的细胞超过6C;分化细胞DNA含量则平均为近四倍体值(DI=2.03和1.99),其中近60%的细胞少于4C。两者差异统计显著,表明形态分化的人胃腺癌细胞的遗传物质含量明显减少,但这些细胞并非就是正常二倍体细胞。     

甘蔗幼叶切段培养中的体细胞胚胎发生

本文从形态学和组织学方面研究了甘蔗幼叶胚性愈伤组织发生及体细胞胚胎的形成过程。甘蔗幼叶片切段培养于含2.4—D1.5mg/1的MS培养基上,4—6天后切段开始形成愈伤组织,约10天后愈伤组织表面出现白色颗粒状结构。将含有白色颗粒状结构的愈伤组织转移至不含激素的培养基中,7—10天后可见有小植株长出。组织学和形态学观察表明,甘蔗离体再生植株是通过体细胞胚胎发生途径。     

Ecotoxicological contamination processes: Interaction with vegetation (a review)

Up-to-date crop production concentrates on the maximisation of plant matter production, both by optimum utilization of solar energy by plants and by the application of additional energy. Therefore a natural strategy is being developed aimed at combining the physiological functions of the assimilation organs with their external shaping and strengthening their variety in space and area. As demonstrated by many deposition studies, this effect is contradictory to the factors conditioning the low deposition capacity of plant covers. A high level of particle, gas and solution deposition increases the danger of food chain contamination and has a negative impact on plant production. Data concentrated on transport values of pollutants and their long-term dynamics in stands could be used for the selection of ideal crop types; therefore every effort should be directed towards selection and breeding.