Analysis of the association among three viruses infecting hop in Australia

Associations among Hop latent virus (HpLV), Hop mosaic virus (HpMV), and Apple mosaic virus (ApMV) were assessed in five hop cultivars at four commercial hop-growing regions in Victoria and Tasmania, Australia. The presence or absence of each virus was confirmed by double-antibody sandwich enzyme-linked immunosorbent assay (DAS-ELISA). Spatial patterns of virus-infected plants were characterized using the Spatial Analysis by Distance IndicEs ( sadie ) system of pattern analysis. The association among viruses (occurrence and covariation) was assessed using the Jaccard similarity index, Spearman's rank correlation coefficient, and sadie . The spatial pattern of plants infected by HpLV and HpMV ranged from random to highly aggregated depending upon the cultivar infected and the mean disease incidence. The spatial pattern of plants infected by ApMV was aggregated in six of the seven plots where ApMV was present. A strong positive association between HpLV and HpMV was found in all cultivars at all locations. This association may be the result of the viruses sharing a common aphid vector species, the presence of one virus enhancing the ability of the aphid vector to acquire the other virus either through transencapsidation or influences on virus titre, or mixed infections within source plants. Significant associations, positive or negative, were found less frequently between HpLV and ApMV, and HpMV and ApMV.     

黄瓜叶色突变体遗传机制的研究

 从黄瓜雌性系9110G中发现能稳定遗传的叶色突变体。该突变体子叶和第1～2片真叶最初为金黄色，叶绿素含量约为正常株的3／5，但随着叶片的生长这些叶片逐渐转绿。该突变体叶色黄主要是由叶绿素降低引起的，与类胡萝卜素无关。通过对亲本、F。、BE及F2后代观察和叶绿素测定，证明该突变体是细胞核遗传，由单一隐性基因控制，并且绿色对黄色为不完全显性。该突变性状是研究光合系统和基因定位的好材料，同时也可用来作为指示性状鉴定杂种纯度。     

纤维粗度对浆张性能的影响

利用纤维质量分析仪研究针、阔叶木浆打浆后的纤维形态，观察打浆后的纤维粗度及测定手抄片的性能。结果表明，打浆能改变纤维的粗度，从而影响手抄片的物理性能和不透明度。     

山羊传染性胸膜肺炎支原体和绵羊肺炎支原体对抗菌药物敏感性的研究

测定了环丙沙星、氧氟沙星、单诺沙星、红霉素、罗红霉素、泰乐菌素、泰妙菌素、四环素等8种药物对羊肺炎支原体两个标准株Y-98和Y-goat的体外抑菌浓度以及红霉素与氧氟沙星、泰乐菌素对Y-goat和四环素与氧氟沙星、泰乐菌素对Y-98的联合药敏作用.结果表明,这8种抗菌药物对Y-goat和Y-98的MIC(μg/mL)分别为:环丙沙星0.223、0.002 23,氧氟沙星0.281、0.014 0,单诺沙星0.136、0.014 0,红霉素0.021 8、无效,罗红霉素0.032 7、无效,泰乐菌素0.042 2、0.039 0,泰妙菌素0.021 7、0.052 0,四环素0.195、0.052 0.红霉素与氧氟沙星的联合药敏指数为1,是相加作用;红霉素与泰乐菌素对Y-goat的联合药敏指数为1.5,是无关作用;四环素与氧氟沙星、泰乐菌素对Y-98的联合药敏试验指数均为0.375,是协同作用.     

铺散诸葛菜的组织培养及植株再生

 以铺散诸葛菜的叶柄及叶片为外植体, 研究了不同的再生方式。在6-BA 和NAA 配合使用的MS 培养基上, 叶柄和叶片外植体有高的成芽率, 具有强的器官再生能力。在2,4-D 与6-BA、NAA 结合的培养基上, 叶柄和叶片有较高的愈伤组织诱导率, 在含6-BA 的培养基上也易于分化。叶柄、叶片再生的芽和经愈伤组织分化而得来的芽快速繁殖后, 在生根培养基上形成完整植株。研究表明铺散诸葛菜具有极强的器官分化能力。     

胞质雄性不育性在叶用芥菜上的利用

以从美国威斯康星大学引进的叶用芥菜胞质雄性不育系叶用4-4为母本,以泰国清迈大学选育出的8个优良叶用芥菜品种为转育父本,杂交后连续回交4代(BC4),再将BC4与优良叶用芥菜品种40R2-3-4配制8个杂交组合,其中2个组合(4-4 × 19-H-12)×40R2-3-4和(4-4 × 2R2)×40R2-3-4结球率为100％,产量比商用品种分别高34％和13％,比其亲本分别高25％和5％。     

甘肃省生态环境综合评价指标体系研究

甘肃省生态系统分为社会经济系统和自然生态系统两大类 ,社会经济系统指标体系由社会经济条件和人为环境压力构成 ;自然生态系统由水环境、森林生态系统、草地生态系统和土壤生态系统四个次一级系统组成 ,每个次一级生态系统由各自所属指标体系来系统评定。利用因子分析法、Delphi法和头脑风暴法经过多次综合专家意见最终确定 2 6项指标作为甘肃省生态环境质量综合评价体系。利用层次分析法 (AHP)定量各指标的权重。通过综合评价表明 ,甘南州、陇南地区、张掖地区的生态环境质量较好 ,甘肃中部广大黄土高原地区次之 ,河西走廊的武威市、金昌市和嘉峪关市环境质量最差。评价结果真实地反映了甘肃省生态环境的基本状况 ,说明该指标体系具有科学性 ,能够用于不同地区之间或同一地区不同时间的环境质量对比与变化研究。     

耕作方式与长期定位施肥对雨养农田冬小麦产量的调控效应

为了明确西北黄土高原半湿润偏旱区耕作方式与长期定位施肥对冬小麦产量的调控效应,以设在半湿润偏旱区连续12年的耕作与肥料长期定位试验为平台,采用裂区设计,以传统耕作和免耕耕作为主处理,不施肥(CK)、单施无机氮肥(N)、单施无机磷肥(P)、单施有机肥(M)、无机氮磷肥配施(NP)、有机无机肥配施(NMP)为副处理,栽培制度为1年春玉米-3年冬小麦轮作,研究耕作及施肥措施对冬小麦产量的影响及其在生产年型间的变化关系。结果表明,不同年型及耕作方式均以有机无机配施冬小麦产量最高,有机肥单施高于化肥单施,磷肥单施高于氮肥单施。耕作方式间表现为传统耕作高于免耕耕作,年型间表现为丰水年>平水年>干旱年,耕作和施肥方式的增产效果以干旱年最好,平水年和丰水年差异不显著。有机无机配施与传统耕作结合优化了冬小麦冠层温度、叶绿素相对含量等生理指标,提高了光合速率、气孔导度及蒸腾速率,因而改善了有效穗、穗粒数和千粒重等产量性状而使冬小麦增产。在550 mm左右降水量的陇东旱塬雨养农业区,无论何种耕作方式及生产年型,长期采用有机无机或无机氮磷肥配施均表现出持续提高冬小麦产量的良好作用。因此,有机无机配施结合传统耕作是提高陇东半湿润偏旱区冬小麦产量的最佳耕作栽培模式。     

基质对黑果腺肋花楸幼苗生长的影响

以黑果腺肋花楸(Aronia melanocarpa)为试验材料,选用田园土、泥炭土、珍珠岩和黄沙,采用正交试验设计,研究不同基质配比对黑果腺肋花楸成苗率以及幼苗形态指标和生理指标的影响。结果表明,不同育苗基质对黑果腺肋花楸出苗率、苗高、地径、主根长、侧根数和高径比等形态指标以及根系活力、可溶性糖、淀粉和蛋白质等生理指标的影响差异显著,综合分析各项指标,筛选出适合黑果腺肋花楸容器育苗的栽培基质为田园土(40%)+泥炭土(30%)+黄沙(30%)、田园土(40%)+珍珠岩(30%)+黄沙(30%)、田园土(40%)+泥炭土(30%)+珍珠岩(30%)和田园土(60%)+泥炭土(20%)+黄沙(20%)。     

The value of vegetation cover for ecosystem services in the suburban context

Latin-American cities can be characterized by dynamic processes of urbanization that encroach upon the natural and semi-natural surrounding landscapes. Our study presents the effects of landscape development, transformed from semi-natural conditions into a mostly disperse suburban settlement. We explore the impact that this transformation has had on this context by three ecosystem services that regulate rainwater runoff, enhance microclimate conditions and help to improve air quality by monitoring vegetation cover. We have designed a spatio-temporal hierarchical analysis which employs remote sensing techniques to capture the structural changes of this landscape over long, medium and short term scales on two spatial levels. This methodological approach was tested in the Metropolitan Area of Santiago (MAS) as case study area. Despite of the increase in impervious surfaces due to urban processes, there has also been an increase in vegetation cover, which has led to an improvement in the provision of the above-mentioned ecosystem services. Hence, if diverse urbanization processes continue and they are coupled with an increase in vegetation cover, the provision of ecosystem services could also expand. This phenomenon can be observed in some areas, where public and private green spaces are created and maintained. Our data analyses give evidence that certain types of suburban areas which increase the share of vegetation cover can provide daily ecological benefits for urban neighborhoods, and beyond, for adjacent areas. Moreover, suburban development can successfully provide ecological benefits to citizens. Such processes can only be ecologically sustainable if the composition of vegetation is well-adapted to the regional climatic conditions.