更生霉素诱发向日葵离体培养细胞变异

向日葵愈伤组织经更生霉素处理后,其生长速度明显降低。细胞学观察发现,细胞染色体结构和数目均发生了变化。     

Interpretation of commercial production information: A case study of lulo (Solanum quitoense), an under-researched Andean fruit

Every time a farmer plants and harvests a crop represents a unique event or experiment. Our premise is that if it were possible to characterize the production system in terms of management and the environmental conditions, and if information on the harvested product were collected from a large number of harvesting events under varied conditions, it should be possible to develop data-driven models that describe the production system. These models can then be used to identify appropriate growing conditions and improved management practices for crops that have received little attention from researchers. The analysis and interpretation of commercial production data in the context of naturally occurring variation in environmental and management, as opposed to controlled experimental data, requires novel approaches. Information was available on both variation in commercial production of the tropical fruit, lulo (Solanum quitoense), and the associated environmental conditions in Colombia. This information was used to develop and evaluate procedures for the interpretation of the variation in commercial production of lulo. The most effective procedures depended on expert guidance: it was not possible to develop a simple effective one step procedure, but rather an iterative approach was required. The most effective procedure was based on the following steps. First, highly correlated independent variables were evaluated and those that were effectively duplicates were eliminated. Second, regression models identified those environmental factors most closely associated with the dependent variable of fruit yield. The environmental factors associated with variation in fruit yield were then used for more in depth analysis, and those environmental variables not associated with yield were excluded from further analysis. Linear regression and multilayer perceptron regression models explained 65-70% of the total variation in yield. Both models identified three of the same factors but the multilayer perceptron based on a neural network identified one location as an additional factor. Third, the three environmental factors common to both regression models were used to define three Homogeneous Environmental Conditions (HECs) using Self-Organizing Maps (SOM). Fourth, yield was analyzed with a mixed model with the categorical variables of HEC, location, as a proxy for cultural factors associated with a geographic region, and farm as proxy for management skills. The mixed model explained more than 80% of the total variation in yield with 61% associated with the HECs and 19% with farm. Location had minimal effects. The results of this model can be used to determine the appropriate environmental conditions for obtaining high yields for crops where only commercial data are available, and also to identify those farms that have superior management practices for given environmental conditions.     

人工授精技术在柞蚕与栗蚕远缘杂交中的应用

研究柞蚕(Antheraea pernyi)与栗蚕(Dictyoploca japonica)的人工授精技术,并应用于柞蚕与栗蚕的种间杂交试验,为利用远缘杂交改良柞蚕的经济性状提供试验技术。从种内交配40～60 min的柞蚕雌蛾交配囊中采集精子细胞用于对柞蚕处女蛾的人工授精,其受精蛾率为61.5%,受精卵率为70.5%,孵化卵率为60.8%。栗蚕精子可在种内交配40～75 min的雌蛾交配囊中采集。利用单蛾精液授精和单蛾与多蛾精液互补授精的方法,分别获得了栗蚕♀×柞蚕♂的越冬卵和蚁蚕及柞蚕♀×栗蚕♂的活胚胎。试验结果表明,采用初步建立的人工授精技术,可以进行柞蚕与栗蚕的远缘杂交。     

三江源区人工草地建植适宜区地理信息系统

综合应用草原生态学原理、GIS理论、计算机软件技术,通过解决三江源区多层空间数据及其属性数据科学集成应用的关键技术问题,自主设计和开发了关于三江源区人工草地建植适宜区分析的地理信息系统,为3S技术在青海草业科技中的进一步推广应用打下了基础.     

陕西卫矛愈伤组织诱导的初步研究

以陕西卫矛幼茎为外植体,以MS培养基为基本培养基,采用正交实验研究了不同种类、不同浓度的植物生长调节剂及其组合对陕西卫矛愈伤组织诱导的影响.结果表明:以幼茎为外植体,其愈伤组织诱导率较高,最适愈伤组织诱导培养基为MS+6-BA 3.0mg/L+NAA 0.2mg/L+30 g/L蔗糖.     

补播对中度退化高寒草地群落特征和多样性的影响

为研究补播对高寒草地群落特征和植被多样性的影响,本研究以黑土滩中度退化草地为对象,利用免耕补播机通过近自然补播措施进行了恢复,测定了恢复后草地的群落组成及多样性特征。结果表明：经人工补播后,退化草地的植被盖度,地上、地下生物量,禾本科牧草比例和根冠比都显著上升（P<0.05）,补播措施起到了很好的修复效果。从物种组成上看,退化草地经过补播之后,其植被群落组成和物种重要值都发生了变化。其中,禾本科牧草和莎草科牧草占据了重要地位。此外,物种丰富度指数、Shannon-Weiner指数、均匀度指数经人工补播后都有所上升,但差异不显著。综上所述,人工补播是高寒地区黑土滩中度退化草地修复一种快速有效的措施,能够有效的提高可食牧草的比例,同时也有利于高寒地区草地植被恢复。     

黄土区煤矿排土场重建草地土壤剖面有机碳变化特征

以黄土区露天煤矿排土场的4种人工草地和自然恢复的撂荒草地为主要研究对象,研究了草地重建对排土场重构土壤有机碳含量和分布的影响。结果表明:人工草地显著提高了表层土壤有机碳含量,0~10 cm土层有机碳含量达到了4.95 g·kg^-1,撂荒草地对各土层有机碳含量都没有显著提高;4种人工草地土壤有机碳含量剖面分布为:在0~10 cm土层为苜蓿(Medicago sativa) >沙打旺(Astragalus adsurgens) >甘草(Glycyrrhiza uralensis) >冰草(Agropyron cristatum),在10~100 cm各土层为甘草 >冰草 >苜蓿 >沙打旺;排土场人工草地土壤有机碳含量随土层深度的增加而降低,0~10 cm到10~20 cm降低幅度最大,20~100 cm土层之间降低幅度较小无显著差异;排土场人工草地0~100 cm土层SOCD平均值为3.02 kg·m^-2,是撂荒草地的1.72倍,新建排土场的1.99倍,达到了小流域退耕草地的79%,原地貌草地的62%。草地重建影响排土场土壤有机碳剖面分布,显著提高了表层土壤有机碳储量所占比例,苜蓿和沙打旺较大程度的提高了表层土壤有机碳含量,冰草和甘草对0~100 cm各土层有机碳含量均有一定的提高。     

东方白鹳迁地保护研究现状及发展趋势

通过对国内东方白鹳迁地保护研究的最新成果的总结和归纳，对在研究工作中存在的问题提出了几点建议。上海动物园于1984年人工繁殖成功东方白鹳尚属首次。据统计目前世界共有88家动物园饲养繁育约552只东方白鹳，其中，中国就有58家动物园饲养东方白鹳342只。我国对东方白鹳的研究偏重于生态、生理、繁殖三方面，并在笼养繁殖方面取得了突破性进展。     

Induction and effector phases of the immune response: Physiological and pathophysiological features

A review is given on the current state of knowledge about the induction and effector phases of the immune response. Physiological and pathophysiological features of the regulation of the immune response are discussed comparatively for both man and animals.     

两种人工栽培藏茵陈生物学特性的研究

通过椭圆叶花猫(Halenia elliptica D.Don)、四数獐牙菜(Swertia tetraptera maxim)的人工栽培试验表明:两种藏茵陈植物都为两年生草本,第一年仅以叶簇形态生枝条不伸长,只进行营养生长,生长第二年枝条才开始伸长,开花结实后完成生活史;两种藏茵陈播种时间都以秋播为宜,有利于自然通过低温春化作用打破种子休眠,促进翌年春天种子萌发,显著提高田间出苗率;两种藏茵陈通过人工栽培,其茎、叶都比野生植物生长高大、粗壮,可大幅提高生药产量,是保护珍稀野生植物资源的有效途径之一;两种藏茵陈50%以上的种子在土壤中有较长期的休眠特性,一般在一年中的春秋两季萌发,所以适当增加播种量第二年后可使田间一年、二年生植株同时生长,对生药生产可连年持续收获产品,免去了对土壤的耕、翻、耙、种等作业,从而可有效降低栽培成本。