Effects of relative humidity, light intensity and photoperiod on the colony development of Erysiphe sp. on Rhododendron

Growth and reproduction by powdery mildew pathogens is generally inhibited by decreasing relative humidity. With Erysiphe sp. on Rhododendron cv. Elizabeth, the initial stages of colony development were adversely affected by reducing the relative humidity from 100% to 70 and 85%. No significant effects on secondary or tertiary hyphal development were detected. Light intensity and photoperiod both had considerable effect on the induced resistance response of the host. Over the initial 5 days of colonization there were no significant differences between any of the treatments. After 13 days, however, expansion of fungal colonies at 180 photosynthetic active radiation (PAR) was limited solely to the area initially infested by primary hyphae. By comparison, in colonies grown at 80 PAR regardless of day length, secondary and tertiary hyphae had extended beyond the area first colonized. These effects resulted in differing morphologies, small colonies of densely packed hyphae formed at 180 PAR compared with open spreading colonies at 80 PAR.     

杜鹃花新品种‘朝晖’和‘红晕’

 ‘朝晖’杜鹃花是由大白花杜鹃和马缨花杂交选育而成, 叶面灰绿色, 顶生圆锥伞房花序, 有花10～12 朵, 花冠紫红色。‘红晕’杜鹃花是由露珠杜鹃和马缨花杂交选育而成, 叶浅绿色, 花冠漏斗状钟形, 花冠上部粉红色, 下部乳黄色, 有紫红色斑点。     

阿魏酸对2种野生杜鹃种子萌发的化感作用

为探究化感物质阿魏酸对马缨杜鹃和露珠杜鹃种子萌发的化感作用,本研究采用不同浓度阿魏酸分别处理马缨杜鹃和露珠杜鹃种子,利用单因素方差对其发芽率、发芽势、发芽指数和化感指数进行差异性分析.结果表明:阿魏酸显著抑制马缨杜鹃和露珠杜鹃种子的萌发,对2种杜鹃种子的抑制作用随浓度的增加而增加.阿魏酸对马缨杜鹃和露珠杜鹃种子均具有显著的化感作用,化感效应的最强浓度为1 000 μg/mL.     

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.     

云南松直干、弯干材木材结构比较观察

利用光学显微镜对云南松直干、弯干材木材构造进行解剖学观察，结果表明：弯干材在解剖结构上跟直干材基本保持一致。与直干材相比，弯干材的早材比直干材的早材窄，树脂道多；早、晚材管胞的长度、壁厚、弦向直径差幅分别为：0．14、0．63、4．4、13．56、-0．46、0．81；最大交叉场纹孔数和最大单列射线细胞个数比直干材分别多1个和2个；纺锤形射线高度超出直干材的51．73％。弯干材具有右旋扭转纹。另外，两种材料都是较好的造纸原料，且以弯干材为优。     

黄连、黄芩提取液与二氧化氯复配对结球甘蓝种传黑斑病的抑菌效果研究

采用三元二次回归正交旋转组合设计方法,确立了黄连、黄芩提取液与二氧化氯对甘蓝链格孢菌抑制效果最佳的复配组合:黄连提取液13.48%、黄芩提取液15.56%、二氧化氯0.14%.用此复配剂浸种,芸苔链格孢菌和甘蓝链格孢菌的侵染率分别降低了97.33%和94.85%,且提高了种子发芽势及萌发相关酶活性.     

贵州百里杜鹃保护区的杜鹃属植物种类及其观赏特性研究

贵州西部百里杜鹃保护区的杜鹃属植物种类关系到其保护区的价值。经过调查研究,该保护区计有杜鹃属植物33种(含变种),分属于5个亚属,占贵州现有杜鹃属植物种类111种的29.73%;并发现了西昌杜鹃和白花杜鹃两个贵州的新分布种;进而从园林的角度,论述了这些杜鹃属植物种类花的颜色、大小及花期等的观赏特性。     

水团花扦插繁殖试验

为尽快解决制约水团花发展的种苗问题,于2003年在厦门市同安区林业局上埔苗圃的联栋大棚内进行了APT1号生根粉7种不同浓度及6种不同扦插基质的水团花扦插育苗试验,结果为生长激素以400~500mg.kg-1ABT1号生根粉处理效果最好,以红心土+火烧土、红心土+河沙、红心土+腐殖质土为佳。     

云南含笑开花生物学特性的初步研究

依据云南含笑产区和引种区调查观测材料,分析研究了云南含笑开花的生物学特性。结果表明,云南含笑是木兰科植物系统发育上一个很自然而又比较进化的种,分布于云南中部以及西北部的是比较原始的种群,分布于贵州的云南含笑是比较进化而年轻的种群。云南含笑观赏价值和经济价值高,可作为园林树种及香料树种加以推广应用。本文为今后的推广应用提供了相关参考分析依据。     

毛白杜鹃耐碱突变体的离体筛选与鉴定

利用由NaHCO3建立的高pH值筛选培养基对毛白杜鹃组培再生的丛生芽进行了耐碱筛选,并对获得的耐碱突变体植株在碱性环境中叶绿素含量和根系Fe3+还原酶活性变化进行了分析.结果表明:10mmol/LNaHCO3是合适的选择压,突变体植株对碱性环境比对照具有较好的适应性和耐受性;该筛选方法是可行的.