福建省6种早熟良种柚的RAPD分子标记研究

采用改良的CTAB法成功提取龙柚等6种福建省旱熟良种柚叶片的DNA,并对其进行RAPD分析．从初选的100个随机引物中筛选出12个扩增效果较好的引物,对提取的DNA进行PCR扩增,获得清晰可重复的位点107个,平均每条引物产生的位点为8．9个,其中多态性位点93个,占86．9％;在部分样品中检出了特异性RAPD标记24个,占23．4％：样品间遗传相似系数比较和UPGYA聚类分析表明坪山柚和文旦柚的亲缘关系最近,度尾蛮柚和四季柚分别与其它5个柚类的亲缘关系较远．     

Leaf morphology correlates with water and light availability： What consequences for simple and compound leaves？

Leaves are organs sensitive to environmental changes in the process of evolution and may exhibit phenotypic plasticity as a response to abiotic stress.However,affirmation of leaf morphological plasticity and its regulations in different environments are still unclear.We performed a simulated experiment to study the variations of leaf morphology in different gradients of water and light availability.Considering different types of leaves and venation,we chose pinnate-veined simple leaves of Quercus acutissima and compound leaves of Robinia pseudoacacia as the study objects.The morphological parameters we investigated include leaf size,shape and venation pattern which can be easily measured in the field.Significant variations occurred in many parameters due to the effects of the environment and/or allometry.There were broadly consistent trends for leaf morphological variations along the gradients.The leaf size became smaller with a short supply of resources.Leaf elongation and fractions of the lamina area altered to enhance resources acquisition and conservation.Trade-offs between investments in support and functional structures optimized the venation pattern of major and minor veins.Leaflets partially played a role such as leaf teeth,for they are not only individual units,but also a part of the compound leaf.We suggest that more or less the same trends in morphological variations may be an important explanation for coexisting species to adapt to similar habitats and form the niche differentiation.     

采用梯度滤波方法的夜间车辆检测

研究视觉交通监控的夜间车辆检测问题,提出一种基于视频图像处理提取夜间交通车辆完整轮廓的方法.通过梯度滤波消除路面反光的干扰,然后对经过预处理的相邻视频帧图像实行三帧差分分割运动区域,最后设计级联形态学滤波器对获得的车辆轮廓进行规整.多段典型的夜间交通视频测试结果表明,方法能有效地消除路面反光和环境光照的干扰,准确地提取夜间交通车辆的完整轮廓.     

光学相关取零阈值实现击中与否运算

为避免传统的双通道光学相关实现击中与否运算中由累计效应引起的误差,基于数学形态学的对偶法则,提出使用对双通道光学相关取零阈值的方法来实现击中与否运算,使PC机取阈时不存在误差.     

王锦蛇,红点锦蛇的形态、核型和Ag-NORs比较

本文对王锦蛇Elaphecarinata和红点锦蛇E.rufodorsata的形态特征及染色体的相对长度、臂比指数和Ag-NORs进行了比较分析。两种锦蛇在形态特征上存在明显差异,染色体相对长度和臂比指数存在明显差异;两种锦蛇的Ag-NORs无差异。讨论了锦蛇属的核型,银带在分类特征上的意义。     

检疫性杂草硬雀麦（Bromus rigidus Roth）

本文从检疫性杂草硬雀麦的分布、危害及其生物学特性进行概述,对其植株、花、果、种子的形态特征进行研究与分析,为口岸提供快速、准确的检疫鉴定,提高疫情检出率,及为有效地防止其传入、传播和危害提供资料依据。     

论影响英语语素变体的若干因素

语素既是英语中音义结合的最小单位,又是语法分析的最小单位。在实际使用过程中,英语语素往往会受到语音、形态、语法、词汇等因素的制约,从而产生变异现象。