不同轮回选择方法对玉米窄基群体的改良效果

利用轮回选择进行群体改良,是玉米种质扩增与改良的有效方法,能为选育优良自交系提供基本素材,进而提高选育自交系及杂交种的效率。本研究以玉米窄基群体P4C0及其经过不同轮回选择方法改良的10个群体为材料,通过多点田间表型鉴定和配合力测定,研究不同轮回选择方法对玉米窄基群体的改良效果,利用SSR分子标记分析不同轮回选择方法对群体遗传多样性的影响。结果表明,几种轮回选择方法都能有效改良群体的主要性状及其一般配合力(GCA)。以时间计算,控制双亲混合选择(MS)对群体P4C0主要性状及其GCA改良效果优于半同胞-S2:3(HS-S2:3)轮回选择,但在株高和穗位高的改良上,HS-S2:3选择效果较好。以轮次计算,开放改良对群体P4HSC1主要性状及其GCA的改良效果优于MS,但开放改良后,群体株高和穗位高有较大幅度的增加。不同轮回选择方法对群体遗传多样性和遗传结构的影响不尽一致。P4C0经过5轮MS后,在群体改良的低代,群体遗传多样性得到了较好的保持,而多代的改良导致群体遗传多样性下降;P4C0经过1轮HS-S2:3选择后,遗传多样性比P4C0有较大幅度的下降。P4HSC1经过1轮开放改良后,遗传多样性有较大幅度的增加。P4HSC1经过3轮MS改良后,群体遗传多样性呈增大的趋势,但每轮增加的幅度均较小。     

山西不同居群野生草地早熟禾的坪用性状评价

为评价山西不同居群野生草地早熟禾（Po apratensisL.）的坪用特性,采用完全随机区组设计,将山西20个不同居群野生草地早熟禾种质进行试验评价。通过对出苗期和成坪期的观察以及生长速度、再生速度、盖度、密度、质地、色泽、均一性、越冬率等指标的测定,对其坪用性状进行综合评价。结果表明：沁水Ⅱ和浑源Ⅱ居群的野生草地早熟禾出苗早、成坪速度快;沁水Ⅱ居群野生草地早熟禾的越冬率、密度和盖度高于对照和其他野生居群,沁水Ⅱ和浑源Ⅱ居群野生草地早熟禾的质地最佳,五台和沁水Ⅱ居群叶绿素含量显著高于其他居群（P<0.05）。沁水Ⅱ和浑源Ⅱ居群野生草地早熟禾的综合质量表现均衡且分值较高,适宜作为草坪草种植,是推广应用的最佳选择。     

农田害鼠长期运动规律与持续控制技术研究

根据临海市1985—2004年农田鼠情监测情况,阐述了农田鼠类种群结构时空变化特征,揭示了农田鼠类运行的四个阶段特征以及长期运动规律,创建了鼠类种群数量变动的Logistic模型:Y(t)=22.8818/(1 0.1038e0.2219X)、X=｛1,2,3,……,n｝。提出了以农田生态调节为基础、积极保护利用天敌为重点、推广群众性测报防治为关键、改进药物灭鼠技术和因地制宜分类做好防治为保障的持续控制技术。2000—2004年推广应用面积8.04万hm2,将农田鼠密度控制在3%以下,将农田鼠害率持续控制在0.5%以下。     

西藏野生油菜及其近缘种的遗传多样性中心

本文以100份西藏野生油菜及其近缘种种质资源为材料,运用群体遗传学的原理与方法,对西藏野生油菜及其近缘种种质资源的数量和遗传多样性指数的生态地理分布特征进行了研究。结果表明：1）在水平分布上,西藏野生油菜及其近缘种形成了28—31°N×88—94°E和29—32°N×96—99°E两个区域明显的遗传多样性中心,其中28—31°N×88—94°E的藏中地区野生油菜及其近缘种种质资源分布广泛,遗传多样性丰富,29—32°N×96—99°E的藏东横断山脉地区野生油菜及其近缘种种质资源数量和遗传多样性次之。2）在垂直分布上,以海拔3500－3600m、3800－3900m、4000－4200m为中心,形成了三个不同的遗传多样性中心区,并发现海拔3700－3800 m是低海拔遗传多样性丰富区和高海拔遗传多样性丰富区的临界带。3）据西藏野生油菜及其近缘种遗传资源的数量和遗传多样性指数的水平分布和垂直分布规律,提出了西藏野生油菜及其近缘种的遗传多样性中心及其多样性扩散方式。     

秦岭北坡水灾迹地岭南核桃种群数量特征与生长的初步研究

本文初步研究了秦岭北坡水灾迹地岭南核桃种群数量特征、生长和存活动态。水灾造成很多生长在泥石流迹地中的核桃树损毁,改变了核桃种群的数量特征和存活动态。调查结果表明,水灾迹地核桃种群为增长型,地径0—15cm的个体占到79．3％。存活曲线为Ⅲ型。人为耕地开垦、水灾和人工栽培是促进核桃种群更新的原因。自然和人为干扰是塑造核桃种群发展型和存活动态的主要因素。结合种群自疏过程,强调了核桃个体发育对空间和资源的不断占据是种群存活动态的根源。最后,依照核桃生长的生物学特征,提出了核桃种群栽培和丰产的一曲瘴议．     

广东五桂山四药门花种群生态学研究

四药门花（Loropetalum subcordatum）是我国特有的稀有植物,仅零星分布在香港、广东和广西。中山五桂山是四药门花自然种群的主要栖息地之一。在五桂山四药门花种群所在的次生林群落中设置样方,调查样方内树种名称及其胸径和树高;采取相邻格子法,记录样方内所有四药门花植株及其大小。调查结果表明四药门花所在的次生林群落以降真香（Acronychia pedunculata）、四药门花和铁榄（Sinosideroxylonwightianum）等树种为优势。在400 m2的样方中,乔木层树种丰富度指数为2.10～4.08,灌木层为5.81～8.37;乔木层Shannon-W iener多样性指数为1.42～2.51,灌木层为2.78～3.89;乔木层树种均匀度指数为0.59～0.84,灌木层为0.81～0.92。种群调查结果表明四药门花种群小,以Ⅲ级小树（2.5 cm≤dbh≤7.5cm）为优势,缺乏幼苗和幼树,自然更新不良;四药门花花期长,但自然种群的结实率低。继续开展四药门花自然种群的传粉生物学、遗传多样性和种苗扩繁技术研究有利于该稀有物种资源的保护和利用。     

Plastid DNA variation in Prunus serotina var. serotina (Rosaceae), a North American tree invading Europe

Black cherry (Prunus serotina) is a tree from North America, where it is often used for economical purposes, whereas it is widespread and invasive in Europe. Plastid DNA variation was first investigated in both its native and invasive ranges using microsatellite loci and sequences of three intergenic spacers (trnT-trnL, trnD-trnT and trnS-trnG). This analysis was focused on P. serotina var. serotina, with the inclusion of samples of closely related taxa. Length variation at a microsatellite locus (ccmp5) and a few sequence polymorphisms were identified among P. serotina samples. Four new primer pairs were then designed to specifically amplify variable regions and a combination of five markers was finally proposed for phylogeographic studies in P. serotina. These loci allow identification of six chlorotypes in P. serotina var. serotina, which may be particularly useful to depict the maternal origins of European invasive populations.     

The effect of grape vine cultivars on <Emphasis Type="Italic">Lobesia botrana</Emphasis> (Lepidoptera: Tortricidae) population levels

The European vine moth Lobesia botrana Denis & Schiff. (Lepidoptera: Tortricidae) is a key pest in the vineyards of Israel and Europe. Traps baited with the female sex pheromone are commonly used to monitor the pest population. However, the role of the vine cultivars on monitoring the moth population using pheromone-baited traps was not yet studied. The present study aimed to identify the effect of grape cultivars on L. botrana adult distribution patterns in the field, in order to achieve a better understanding of the monitored data in respect to male and female’s host preference. The 3-year study in commercial vineyards used four cultivars: Carignan, Emerald Riesling, French Colombard, and Cabernet Sauvignon. The moth population of each generation was estimated from male counts in pheromone traps; three generations were observed in all experimental orchards, each year. Female host choice was studied by monitoring freshly deposited eggs and newly hatched larvae on vines. The study showed a significant effect of cultivar on numbers of trapped males in most years, and a cultivar effect on female host choice. For both males and females and for all phenological stages of the grapes, Carignan and French Colombard attracted the most and Cabernet Sauvignon the fewest specimens. The results show that cultivar blend within the vineyard can affect the distribution pattern of the pest. Knowledge of the expected choice of the female moth, and of the timing of its decision could lead to an improved monitoring system, with the preferred cultivar as an indicator.     

Characterisation of Afzelia africana Sm. habitat in the Lama forest reserve of Benin

A study was carried out in the Lama forest reserve of Benin to characterize the habitat of Afzelia africana Sm., an endangered multipurpose tree species (found in African humid, dry forests and woodlands), in order to define a sustainable management strategy for its conservation. An estimation of species density was done on 100 square plots of 1 ha each, while tree height and dbh of all the species were measured on subplots of 50 m × 30 m within the 1 ha plots. The regenerations of A. africana (dbh < 10 cm) were counted in the diagonal quadrats of the principal plots. Presence–absence data of the species was subjected to multidimensional scaling and results showed four vegetation communities including: young fallow, old fallow, typical dense forest and degraded dense forest. Significant differences were noted between the four communities with respect to dendrometric parameters of the species. High values of these parameters were noted for the species in typical dense forest (5.2 stems/ha, 66.7 cm, 17.9 m, 7.9 m²/ha and 38.8% for the tree-density, the mean diameter, the mean height, basal area and basal area contribution of the species, respectively) whereas the lowest values were obtained for the old preforest fallow as far as the mean diameter (59.7 cm), the mean height (15.7 m) and the basal area contribution (27.7%) of the species were concerned. In general, the basal area of A. africana in the over vegetation types was less than 3 m²/ha. No A. africana tree was found in the young preforest fallow while more than 80% of A. africana trees were found in the typical dense forest community. Stem diameter and height structures of the species in all the four communities showed a left dissymmetric Gaussian shape and were well adjusted to Weibull distribution.     

铁路物流中心绩效的模糊综合评判

从铁路物流中心自身的营运状况和顾客的满意程度两个角度,选取货运周转率、货运设备利用率、专业化营运能力和客户满意度等4个一级指标,车辆周转率、货物换算周转量、货场利用率、搬运设备利用率、货运车辆满载率、装卸设备利用率、存货周转率、物流服务深度、专列货物换算周转量、信息技术使用率、顾客投诉率和顾客忠诚度等12个二级指标构建出铁路物流中心绩效评价指标体系。将模糊综合评判方法应用于铁路物流中心的绩效评价,并用具体案例证明该指标体系及模糊综合评判方法应用于铁路物流中心绩效评价的科学性和准确性。