Infectivity and Effectivity of Some Frankia Strains from the Rhamnaceae Family

The nodulation ability was determined of native Frankia strains (ChI1, ReI4, ReI6, TtI42, and TqI15) isolated from rhamnaceous species indigenous to Chile. All strains tested nodulated other Rhamnaceae host species within one or more genera, i.e., TtI42 nodulated seedlings of Trevoa trinervis, Retanilla ephedra, and Talguenea quinquenervia. Trees from other families such as Casuarina (Casuarinaceae) were not nodulated by the Frankia strains mentioned above. These results suggest that the five strains isolated from rhamnales could belong to the same cross inoculation group because they exhibited the same level of promiscuity. The effectivity of Frankia for nitrogen fixation was established by measurement of acetylene reduction activity in planta. Two strains (ReI6 and TtI42) were found more effective than the others and improved the total dry weight and shoot height of Retanilla ephedra seedlings. These studies may facilitate the choice of selected rhamnaceous Frankia pairs for arid soil afforestation, since these plants are naturally adapted to this environment in Chile.     

Leafminers in vegetables,ornamental plants and weeds in Indonesia: Surveys of host crops,species composition and parasitoids

Extensive surveys of vegetable, ornamental and weedy plant species were conducted in highland and lowland vegetable production areas in Indonesia with the aim of recording leafminer species present and their associated natural enemies. The most common dipterous species reared from samples was the pea leafminer, Liriomyza huidobrensis (Blanchard) (Diptera: Agromyzidae). This introduced pest was particularly serious in highland vegetables in Java, Sumatra and South Sulawesi, causing yield losses as high as 60-70%. Another alien species, the vegetable leafminer, Liriomyza sativae Blanchard, contributed to problems in lowland areas on the north coast of West Java, where cucumbers were heavily damaged. An Asian leafminer species, Chromatomyia horticola Goureau, was more common in snow peas (Pisum sp.). Intensive sampling of leafminer-infested leaves from surveyed host plants yielded 11 species of hymenopteran parasitoids: 10 eulophids (Asecodes sp., Chrysocharis sp., Cirrospilus ambiguus (Hansson and LaSalle), Closterocerus sp., Hemiptarsenus varicornis (Girault), Neochrysocharis formosa (Westwood), Neochrysocharis sp., Pnigalio sp., Quadrastichus sp., Zagrammosoma sp.) and 1 eucoilid (Gronotoma sp.). The most abundant parasitoid species was H. varicornis. Levels of parasitism varied among crops and growing seasons, but were usually low, especially on potato (< 3%). Surveys revealed that most farmers (63%) attempted to control leafminers by applying insecticides twice weekly although these applications were neither effective nor economical according to responses of about 72% of the farmers. An integrated pest management approach is suggested that emphasizes IPM training for vegetable farmers and includes reductionor elimination of broad spectrum chemicals that would adversely affect parasitoids that may already be present as well as those that may be introduced. The initiation of a classical biological control programme is recommended to enhance the limited parasitoid complex present in Indonesia and increase levels of biological control.     

福建省尤溪九阜山省级自然保护区纤维植物资源调查

采用野外实地调查、资料收集与访谈相结合的方法对福建省尤溪九阜山省级自然保护区纤维植物资源进行调查,结果表明,该区纤维植物共有53科111属180种。可优先考虑开发利用的种类主要有马尾松、毛竹、五节芒、杉木、闽粤栲、琴叶榕、苦楝、白背叶、东南野桐、毛瑞香、了哥王、北江荛花、灯心草、白茅、南蛇藤、山乌桕、枫杨、野葛、肖梵天花、扁担杆、苎麻、小构树、葡蟠等。对该区纤维植物的种类、生活型、数量、利用部位及开发利用途径进行了分析,并提出保护与开发利用措施。     

遮光率对八角幼苗生长的影响

[目的]探讨遮光率对八角（Illicium verum Hook.f.）幼苗生长的影响,为其高产栽培提供参考.[方法]遮光率分别为0％、50％、75％、90％.[结果]种子播种后7d和展开第1对子叶以前,遮光率对八角幼苗生长没有明显的影响.在子叶展开（开始光合作用）后,不同遮光率对八角幼苗生长有明显的影响;随着遮光率的提高,八角幼苗株高、茎粗、叶长和叶宽明显升高,叶片中叶绿素含量也大幅提升,叶片呈现较深的墨绿色;植株的木质化程度则因光照减少而相对变弱.在无遮光条件下,因为光照度较高,八角幼苗株高、茎粗与不同遮光率进行遮光的植株有明显差距.[结论]在八角幼苗期,遮光率对其生长明显的影响,因此应根据需要进行遮光.     

高速公路生态景观林带色彩设计的探讨

色彩设计是生态景观林带营建的关键技术。文章以植物色彩表达媒介、空间层次设计和时间序列配置等理论为基础,结合实例探讨以红、黄、紫和白色为主色调的高速公路生态景观林带的植物配置和景观效果。本设计案例可为华南地区营建大尺度、大色调的高速公路生态景观林带提供科学依据和参考。     

核酶在我国植物抗病毒领域的研究和应用现状

简要介绍了锤头型和发夹型核酶的结构、功能及催化机制,并对我国利用核酶抗植物病毒病害方面的研究和应用现状作一概述。     

植物高温胁迫响应分子机制研究

作为固着生物,植物需要面对持续变化的环境,不断地受到温度和其他非生物因素的影响。未来植物所面临的平均环境温度将会随着全球气候变暖逐渐上升,因此高温愈发成为影响植物生长发育、地理分布及产量的非生物胁迫因子。了解植物对高温胁迫的适应机制,有助于开发耐热品种,改善温暖气候地区植物的生长状况以及提高作物的生产力。植物体中,在分子水平,转录组学及蛋白质组学联合揭示了mRNA以及蛋白水平的植物应答高温胁迫的基因表达模式变化;另外高温胁迫广泛涉及植物体内多种信号转导机制。因此,本综述主要从植物响应高温胁迫分子水平上的转录组、蛋白质组学方面,以及信号转导等方面全面总结了植物响应高温胁迫的研究进展,并对未来的研究前景进行了展望,为了解近几年高温胁迫研究动态和高温胁迫常见研究方式,解析植物高温胁迫耐受机理以及耐高温品种的培育提供参考。     

Patterns of species change in anthropogenically disturbed forests of Madagascar

Five main conclusions arise from this review of the responses of species to anthropogenic disturbance in Madagascar: First, species’ reactions to anthropogenic disturbance are generally negative, but remain poorly known. Our knowledge is patchy among and within higher taxonomic groups; we are still largely gathering case studies. Second, taxonomic groups vary considerably in which proximate factors are most important. Third, several groups show differing responses within different ecoregions. Whether these differences are consistent across groups requires further testing. Fourth, related species often have divergent reactions to disturbance, even within lower taxonomic groupings (families or genera). Thus, we cannot rely on phylogenetic relatedness or even ecological similarity to infer similarity in responses. Finally, disturbance typically reduces species diversity (especially of native and/or endemic species), but also causes species turnover, typically with forest specialists replaced by grassland generalists, and endemics replaced by non-endemics (including invasives). Given these knowledge gaps, we stress the urgency of applied studies that assess species’ ecology, behaviour and health across disturbance gradients, including purely anthropogenic landscapes. Remaining natural vegetation and protected areas will be unable to preserve Madagascar’s biodiversity under the impact of climatic change; we must understand responses of plants and animals to disturbance in order to create buffer zones and corridors combining secondary, degraded and natural habitats.     

海南大学校园垂直绿化植物的调查

通过对海南大学校园垂直绿化植物的调查,发现该校园景观效果较好的垂直绿化植物有41种,隶属36属20科;其中灌木4种,藤本33种,禾草类4种。同时,简要分析了校园垂直绿化存在的问题,并提出了改进建议。     

不同起源林分植物多样性差异显著性测定

对不同起源林分幼树层、灌木层、下草层植物多样性差异显著性进行多指标方差人分析检验，检验结果表明，不同起源幼树层与灌木层差异显著。