A viability study of Fallopia japonica stem tissue

Vegetative regeneration of intact and split nodes of Fallopia japonica (Houtt.) Ronse Decraene was the focus of this greenhouse experiment. Stem material, collected in May, July and September 1997, was cut into 40-mm-long sections and incubated on the surface of moist compost in a greenhouse. All samples showed some regrowth of buds and new shoots from both intact and split nodes in any season. A maximum number of 0.25 buds per intact node was recorded after 6 days in a spring experiment. The vegetative regrowth of shoots generally appeared after 1 week and increased over time with a maximum mean height of 77 mm after 27 days and a maximum number of 0.39 shoots per intact node after 13 days. Adventitious roots developed from both intact and split nodes during both summer and autumn experiments. From this study, a maximum of 90 stem tissue propagules per square metre of F. japonica stand has been estimated. If the plant is cut as part of a control programme, these propagules can produce shoots with growth rates of up to 2.9 mm per day with a good chance of the development of adventitious roots. This considerable potential for vegetative regeneration of stem tissue shows a clear need for guidelines on the safe management and disposal of F. japonica plant material.     

Top 20 environmental weeds for classical biological control in Europe: a review of opportunities, regulations and other barriers to adoption

Classical biological control remains the only tool available for permanent ecological and economic management of invasive alien species that flourish through absence of their co‐evolved natural enemies. As such, this approach is recognized as a key tool for alien species management by the Convention on Biological Diversity (CBD), the European and Mediterranean Plant Protection Organization (EPPO) and the European Strategy on Invasive Alien Species (ESIAS). Successful classical biological control programmes abound around the world, despite disproportionate attention being given to occasional and predictable non‐target impacts. Despite more than 130 case histories in Europe against insect pests, no exotic classical biological control agent has been released in the EU against an alien invasive weed. This dearth has occurred in the face of increasing numbers of exotic invasive plants being imported and taking over National Parks, forests and amenity areas in this region, as well as a global increase in the use of classical biological control around the world. This paper reviews potential European weed targets for classical biological control from ecological and socioeconomic perspectives using the criteria of historical biological control success, taxonomic isolation from European native flora, likely availability of biological control agents, invasiveness outside Europe and value to primary industry and horticulture (potential for conflicts of interest). We also review why classical biological control of European exotic plants remains untested, considering problems of funding and public perception. Finally, we consider the regulatory framework that surrounds such biological control activities within constituent countries of the EU to suggest how this approach may be adopted in the future for managing invasive exotic weeds in Europe.     

Are some weeds sleeping? Some concepts and reasons

Summary Sleeper weeds, a relatively new concept, are defined as a sub-group of invasive plant species for which their population sizes are known to have increased significantly more than 50 years after they became naturalized. The invasions of the European herb Hieracium pilosella into New Zealand, the northeast Asian Fallopia japonica and the Sicilian Senecio squalidus into Britain are presented as well-documented examples of sleeper weeds. While the concept of sleeper weeds has gained some acceptance with weed managers, its application remains a retrospective activity at present. Genetic factors, environmental suitability and anthropogenic disturbance are discussed as they affect sleeper weed status. Accurate botanical records for invasive species over long periods of time are relatively rare and limit documentation of the phenomenon. Some mathematical and ecological problems remain with the concept and its wider application to weed invasion, including the adequacy of the species level for determining sleeper weed status in genetically diverse and widely distributed groups of invasive plants.     

山荞麦在城市绿化中的应用研究

结合山荞麦的生物学特性介绍了其应用研究现状,对山荞麦在城市绿化中的优势及生态效果加以综述,详细解释其用途和繁殖方法。     

何首乌叶原生质体制备与融合研究

[目的]研究何首乌叶片原生质体的制备和融合方法。[方法]用机械法制备何首乌叶片的原生质体,用PEG结合高Ca2+-高p H诱导融合法来诱导其原生质体,研究原生质体的融合现象。[结果]何首乌叶片在25℃和35%的蔗糖溶液中处理30 min能够制备出较多的完整原生质体。用20%PEG融合液处理原生质体20min能够有效地诱导何首乌原生质体的融合,2个细胞的融合效率为11.7%,表明用机械法制备的原生质体也是有活性的。[结论]该技术为何首乌原生质体培育奠定了基础。     

何首乌种特异DNA探针的筛选

为筛选得到何首乌(Fallopia multiflora)种特异DNA探针,通过何首乌gDNA和其近缘植物毛脉蓼(F.multifora var.cillinerve)gDNA之间的的抑制消减杂交(Suppression subtraction hybridization,SSH)得到何首乌的差减片段,再将标记的差减片段和多物种gDNA阵列杂交筛选得到了4条何首乌DNA探针,探针通过反向斑点杂交检测,能很好地区分何首乌及其混伪品.获得的探针在中药鉴定基因芯片的制备及何首乌种质和生药鉴定方面具应用前景.     

Relationships between sulfonylurea herbicide treatment of host plants and the performance of herbivorous insects

Previous work had shown that the sulfonylurea herbicide chlorsulfuron affected the survival of a herbivorous insect species dwelling on a sub-lethally exposed host plant. Further experiments have been conducted to establish whether this negative effect was a single occurrence characteristics for the specific insect-plant interaction and the specific herbicide tested. Three insect-plant interactions were tested for the effects of selected sulfonylurea herbicides, i.e. metsulfuron-methyl, chlorsulfuron and tribenuron-methyl. The species pairs tested were Pieris brassicae/Brassica napus, Gastrophysa polygoni/Fallopia convolvulus and Sitobium avenae/Triticum aestivium. No significant effects on survival and relative growth rate of P brassicae or G polygoni were found when treating the host plants with sulfonylurea herbicides. However, the host plants had a significantly reduced root and shoot growth rate when treated with herbicide. Treating T aestivium with the recommended field rate of metasulfuron-methyl did not cause any change in development time, growth rate or fecundity of S avenae feeding on the host plants. The data presented suggest that the increased mortality observed for G polygoni larvae feeding on chlorsulfuron-treated host plants observed earlier was characteristic for this herbicide and for the specific plant-insect interaction only.     

木藤蓼次生木质部解剖及其生态适应性

以木藤蓼为研究对象,利用显微镜和电镜对其次生木质部进行了解剖研究。结果表明,木藤蓼次生木质部解剖特征主要为:生长轮不明显;散孔材;复空率高;单穿孔;管间纹孔互列;具有宽窄两种类型导管并成组;窄导管具有附物纹孔和螺纹加厚,并叠生。射线主为多列,高达8 mm;射线细胞内具簇状和菱形晶体。木藤蓼与蓼科木本种类具有较为接近的结构,对旱生环境具有高度的适应性。     

不同因子对山荞麦扦插繁殖影响的研究

山养麦花期晚,适应性强,是北方垂直绿化的优良藤本植物.通过不同茎节数、不同切口方式、不同扦插方式和不同插穗部位的扦插试验,结果表明:山荞麦扦插时中部保留3～4个茎节的斜切口插穗,进行倾角小于10.的平插效果较好.