线形杉藻切段离体培养的研究

报导线形杉藻细胞组织离体培养的研究，分别把新鲜线形杉藻体主茎的顶端、中部、基部切成长４－７ｍｍ的小段，置于为１０Ｌ：１４Ｄ，光强１５００Ｌｘ，温度１８￣２４℃，实验重复多次，结果线形杉藻具有很强的离体再生能力，培养３天后在切段上断面的皮层及表皮即出现数量不等的细胞突起，１０天后即可长成幼芽，４０天后可长成长约１０ｎｍ且有分枝的幼体，下断面则产生棉球状细胞团粘附于培养皿上。     

A Dilute and Shoot Strategy for Determining Alternaria Toxins in Tomato-Based Samples and in Different Flours Using LC-IDMS Separation

Alternaria toxins are emerging mycotoxins whose regulation and standardization are in progress by the European Commission and the European Committee for Standardization. This paper describes a dilute and shoot approach to determine five Alternaria toxins in selected food samples using liquid chromatography–tandem mass spectrometry (LC-MS/MS). The strategy involves sample extraction with acidified aqueous methanol, followed by a solvent change accomplished via sample evaporation and reconstitution. The quantification is based on isotope dilution, applying all corresponding isotopically labeled internal standards to compensate possible matrix effects of the analysis. The main advantages of the present method over other existing methods includes simple and effective sample preparation, as well as detection with high sensitivity. The five-fold sample dilution can decrease matrix effects, which were evaluated with both external and internal standard methods. The results demonstrated a limit of quantification lower than 1.0 µg/kg for all five analytes for the first time. The newly presented method showed acceptable accuracy (52.7–111%) when analyzing naturally contaminated and spiked standard samples at the described levels. The method was validated for tomato-based and flour samples (wheat, rye, and maize). The absolute recovery ranged from 66.7% to 91.6% (RSD < 10%). The developed method could be an alternative approach for those laboratories that exclude sample cleanup and pre-concentration of state-of-the-art instruments with enhanced sensitivity.     

影响植物分枝的一些基因及其分子机制

了解植物分枝机理不仅具有理论意义,对于农业、林业、果树、蔬菜和花卉等生产实践更具有重要意义.由于分子生物学的发展,人们有机会获得转基因植物和突变体,利用这些材料从不同角度对植物分枝机理进行深入研究.影响植物分枝的分子机制是多种多样的,对激素感知、激素代谢、激素运输等方面的影响都可以改变植物的分枝状况.目前,分枝的分子机制研究已取得较大进展.     

青杨组织培养快速繁殖

建立了青杨(Populus cathayana)组织培养系统.最适合的外植体是新切下的枝条插入含有蛭石和充足水的营养钵中24 h以上,使其在弱光下迅速长出嫩枝的茎切段和茎尖.茎切段和茎尖外植体经0.1%HgCl2或5%NaClO溶液表面消毒后,接种到大量元素减半、含0.5 mg/L 6-BA和0.03 mg/L NAA的MS培养基上诱导芽,试管苗的生根采用含0.5 mg/L IBA的MS培养基.试管苗茎段的分化依外源激素条件的不同而异.     

绕环式投球伸踏动作对投球球速的影响

通过对甘肃省成年、少年女子垒球队投手与2006年女垒世锦赛优秀投手绕环式投球动作运动学数据的比较,分析绕环式投球动作中伸踏动作对投球球速的影响,给有关教练员和投手的绕环式投球技术训练与改进提供实际参考和理论依据,促进投手投球球速的提高.     

均匀设计在长春花丛生芽培养中的应用

均匀设计方法从试验点在试验范围内“均匀分散”出发，可提高单次实验的效率，以较精细的多统计分析结果，提高了分析结果可靠性。在不降低试验精度的情况下，大大减少试验次数，降低成本，本文将此方法用于长春花丛生芽培养过程化条件的优选工作，结果表明，此方法对于多因素多水平的试验设计有明显的优点。     

结球白菜在个体发育中苗端淀粉粒积累的变化

本文描述了结球白菜苗瑞细胞中淀粉粒的含量在个体发育过程中的变化规律,结果是: 结球白菜苗端在分化和形成叶原基的过程中,淀粉粒主要积累于肋状分生组织细胞中,且随苗端产生叶原基活动的加强而增多;随营养苗端向生殖苗端的转化,其淀粉粒的含量明显减少,转化完成后的生殖苗端细胞中,极少见到淀粉粒。由此可见,淀粉物质的积累和变化与叶原基的分化形成及白菜包心结球有着密切的关系。     

国内外女篮技战术情况的比较研究──附第十二届世界女蓝锦标赛录像资料的统计分析

本文运用统计分析方法，试对第十二届世界女篮锦标赛中的国内外篮球技战术情况进行比较研究。旨在总结经验，探究原因，为中国队改进训练，争取再创辉煌，提供参考意见。     

不同条件下麝香石竹玻璃苗的诱导形成及其生理特性研究

研究了不同培养基及外植体条件下麝香石竹玻璃苗的诱导形成及玻璃苗部分生理特性。本文研究认为：麝香石竹玻璃的形成是培养基和外植体因素相互作用的结果，培养基极端的水分环境可能是导致玻璃苗形成的外在原因。     

AC2 and AC4 proteins of <Emphasis Type="Italic">Tomato yellow leaf curl China virus</Emphasis> and <Emphasis Type="Italic">Tobacco curly shoot virus</Emphasis> mediate suppression of RNA silencing

Tomato yellow leaf curl China virus Y10 isolate (TYLCCNV-Y10) alone could systemically infect host plants such as Nicotiana benthamiana without symptoms. In contrast, Tobacco curly shoot virus Y35 isolate (TbCSV-Y35) alone induces leaf curl symptoms in N. benthamiana. When inoculated into transgenic N. benthamiana plants expressing GFP gene (line 16c), TYLCCNV-Y10 neither reverses the established GFP silencing nor blocks the onset of GFP silencing. In contrast, TbCSV-Y35 can partially reverse the established GFP silencing and block the onset of GFP silencing in new leaves. In the patch co-infiltration assays, the AC2 and AC4 proteins of TYLCCNV-Y10 and TbCSV-Y35 could suppress local GFP silencing and delay systemic GFP silencing, suggesting that they are suppressors of RNA silencing. Comparison of the accumulation levels of GFP mRNA in the co-infiltration patches showed that Y10 AC2 and Y35 AC2 proteins had similar efficiency for suppression of RNA silencing. However, Y35 AC4 protein functioned as a stronger suppressor of RNA silencing than Y10 AC4 protein. There-fore, the pathogenicity difference between TbCSV-Y35 and TYLCCNV-Y10 may be related to the functional difference in their AC4 proteins.