环境应急监测主要技术与方法探析

指出了环境应急监测是环境监测工作的一个重要组成部分,突发性环境污染事故具有形式多样、发生突然、难于处置和危害严重等特点,处置不当,就会造成严重的环境污染和破坏,给人们的生产和生活带来危害。分析了我国环境应急监测技术的现状和存在的问题,对环境应急监测的主要技术和方法进行了初步探讨。     

穗花杉虫害防治初探

穗花杉Amentotaxus argotaenin是第三纪孑遗植物,属国家重点保护对象。近年来穗花杉受到虫害的疯狂啮食,幼苗和幼树死亡严重。通过对穗花杉虫害防治研究,初步掌握了点尾尺蛾的生物学特性和危害特征,以及相应的防治方法。     

Crown projection area of young Pinus sylvestris: A model and its test

In this study we applied a theoretical model for determining the projection area of a Scots pine (Pinus sylvestris L.) crown in different directions. The model is based on the assumption that the foliage elements (shoots) are randomly distributed within a symmetrical crown envelope. The model was tested using photographically measured data for three young Scots pine crowns. The compatibility between calculated and measured values was satisfactory.     

Assessment of somaclonal variability in hop (Humulus lupulus L.) in vitro meristem cultures and clones by molecular methods

In vitro meristem tissue cultures are used for production of virus-free rootstocks of hop (Humulus lupulus L.). Because use of plant tissue cultures is associated with occurrence of somaclonal variability, we assessed somaclonal variability in hop meristem in vitro cultures before and after thermotherapy by different molecular methods (RFLP, RAPD, STS, ISSR and AFLP) and compared it with existing clonal variability of Osvald's clones 31, 72 and 114. No molecular differences were observed between mother plants and in vitro mericlones by RFLP and STS analyses. Amplified molecular differences were found in RAPD and ISSR products of one from five in vitromericlones cvs. Eroica (E5) and Southern Brewer (SB2), respectively. Similarities with mother plants were 0.965 and 0.913 (JSC), respectively. Specific amplified polymorphic products were found for every mericlone and mother plant in AFLP reactions and variability of DNA sequence ranged from 0.824 to 0.993 (JSC). This variability was very similar to determined intra-clonal variability within Osvald's clones 31, 72 and 114 by AFLP analysis. Inter-clonal variability of DNA sequence was exactly higher than intra-clonal variability of DNA sequence in these clones. The molecular differences between Osvald's clone 72 normal and meristem derived were not verifiable. Thermotherapy increased frequency of molecular changes, since amplified differences were found in 14 from 20 in vitro mericlones of cv. Eroica, in 6 from 11 in vitro mericlones of cv. Yeoman and in 15 from 23 in vitro mericlones of cv. Southern Brewer by RAPD and ISSR analyses.     

The Experimental and Commercial Release of Transgenic Crop Plants

With advances in recombinant DNA methods and transformation procedures, it is possible to transfer genes into crop plants from unrelated plants, microbes and animals. Many of the modifications being carried out, or envisaged, are for disease and pest resistance, product quality and tolerance to environmental stress, but there are additional opportunities to modify crops to give specialized products for industrial or pharmaceutical use. Some of the characteristics of transgenic plants are considered, including: transgene copy number, position, expression, stability, pleiotropy, selectable marker genes and somaclonal variation. There have been several hundreds of field trials with transgenic plants, and the first transgenic varieties are likely to be approved for commercial production in 1993. Before releasing transgenic plants, it is necessary to carry out a risk assessment to determine whether the transgenic variety will behave differently from a conventionally bred variety. Assessment procedures are being harmonized internationally by various organizations. There is a growing commitment to apply these genetic modification methods to crops in developing countries, as genes relevant to their crops and environments become available.     

不同贮藏方式对鲜食核桃品质的影响

为研究不同贮藏方式对鲜食核桃在贮藏过程中品质的影响,以“清香”核桃鲜果为试材,分别采用青果贮藏（(0±1) ℃、相对湿度70%～80%）、去青皮的湿果贮藏（(-7±1) ℃、相对湿度70%～80%）及湿果真空贮藏（(-7±1) ℃、相对湿度70%～80%）3种方式贮藏,每15 d对其品质指标进行观察测定。结果表明：随着贮藏时间的延长,所有贮藏方式处理的鲜食核桃的感官品质和营养成分均呈一定的下降趋势。其中,青果贮藏能较好地保持核仁的含水量,维持粗脂肪、蛋白质及可溶性糖含量的稳定性,贮藏后种皮色泽较好,核仁容易剥皮、风味较好,但果壳容易产生霉变;湿果贮藏和湿果真空贮藏可以减轻鲜核桃的霉变,延长了鲜核桃贮藏期,但随着贮藏时间的延长,湿果贮藏核仁水分散失较快,粗脂肪、蛋白质及可溶性糖含量变化较大,使得种皮色泽降低,核仁剥皮困难、风味下降。     

大豆叶黄素的研究进展

叶黄素是对人类健康起着积极作用的功能因子,在保健食品等领域的前景十分广阔,目前已成为功能性食品成分研究中的热点。介绍了大豆叶黄素的结构与功能、检测方法、合成途径和关键基因以及遗传特性和影响因素等方面的研究进展。     

次氯酸钠用于植物培养基灭菌方法初探

对在培养基的配制过程中添加次氯酸钠替代培养基高压蒸汽灭菌的方法进行了研究,取得了如下结果：在培养基凝固后添加次氯酸钠,温度25℃、光照强度2000lx、光照时间为16小时的培养条件下,浓度为360mg/L时,仍有部分培养基污染;在培养基配制过程中,琼脂加热溶解后,趁热在培养基中添加10mg/L次氯酸钠,未发污染。以‘神马’菊花为外植体,在培养基配制过程中加入终浓度20mg/L的次氯酸钠时,植株可以正常生长,而且,生长状况好于高压灭菌组;次氯酸钠浓度高于50 mg/L时,生长状况差于高压灭菌组,而且会产生伤害。     

Summary of Influencial Factors on Pollen Viability and Its Preservation Methods

植物花粉贮藏技术研究是开花生物学特性研究中的一项重要内容。在此，就植物花粉生活力的影响因素、花粉生活力的测定方法、花粉的贮藏步骤、方法进行了概述，列出了部分植物的花粉在不同条件下所能贮藏的时间和贮藏一定时间后的生活力状况，并指出了今后花粉贮藏的方向。     

东方百合试管鳞茎培育方式的比较

为促进试管鳞茎抽薹,缩短其形成商品球的时间,以东方百合试管鳞茎为材料,采用不同的培育方式,研究其品质与抽薹率的影响。对东方百合试管鳞茎不同培育方式的比较研究,结果表明：瓶苗冷藏或用基质冷藏,冷藏后的试管鳞茎生理变化规律相同,即淀粉含量、蛋白质含量均降低,可溶性糖含量和还原糖含量均升高;而用基质冷藏或用瓶苗冷藏,暗培养的试管鳞茎抽薹率都高于光照培养;采用暗培养或光照培养,基质冷藏的抽薹率都高于用瓶苗冷藏。工厂化生产百合种苗时宜采用暗培养试管鳞茎结合种前用基质冷藏的培育方式。