玫瑰主要病害防治

症状：一般发生在叶片，呈黑褐色圆形小斑点；逐渐扩大成为不规则形状，周围为细齿状；再扩大，叶色变黄，整个叶片从叶柄掉落；严重时，植株整个下部落叶成中空状，植株衰弱。     

珍珠梅造林技术

珍珠梅为蔷薇科珍珠梅属，落叶灌木，高2～3m，小叶13～21枚，互生，呈卵状披针形，长4～8cm，叶缘具锯齿。花序圆锥形顶生，排列紧密，长18cm左右，花乳白色，花茎较小，花期6月～8月。珍珠梅分布于我国华北、西北等地。     

四翅滨藜推广前景初探

通过对四翅滨藜生物学特性及四翅滨藜在不同立地条件下造林实验结果的分折，预测了四翅滨藜推广前景，希望对西部地区的生态环境建没有所帮助。     

观赏花灌木——黄刺攻

黄刺玫也称黄刺梅，为蔷薇科蔷薇属落叶灌术，株高1-2米．树皮深褐色，小枝紫褐色，有多数硬而直的皮刺：单数羽状复叶，近圆形或椭圆形，边缘有钝锯齿：花单生，黄色，直径3—5厘米，花瓣多数，5—6月开放：果近球形，7～8月成熟后为红黄色。     

秋茄凋落叶酚酸动态变化及其对新月菱形藻的化感效应

采用生物测试法,以九龙江口的优势藻种新月菱形藻(Nitzschia closterium)为受体研究了秋茄[Kandelia obovata(S.L.)Yong]凋落叶的抑藻作用,并利用高效液相色谱法对其分解过程中的酚酸化感物质进行了分析.通过酚酸对新月菱形藻密度以及生理生化的影响,探讨了秋茄凋落叶对底栖硅藻的化感效应,丰富了安全、有效防治藻类的爆发的理论依据与实践经验,为揭示红树植物与林内微藻间相互关系提供新的科学依据.对新月菱形藻密度测定的研究发现:未分解秋茄凋落叶水提液的抑藻作用存在浓度效应,随着水提液浓度的增加,抑制作用增强;半分解秋茄凋落叶(半分解期t50=42d)水提液对新月菱形藻的生长则无明显影响.高效液相色谱检测结果确定秋茄凋落叶中存在对羟基苯甲酸、香草酸、丁香酸、绿原酸和咖啡酸;随着凋落叶的分解,酚酸的含量下降.标准酚酸物质及混合酸均对新月菱形藻产生化感抑制作用,且随着浓度增大,抑制作用增强.这表明在红树林根际-沉积物-水环境界面上,红树植物凋落物对微藻的繁殖起到了一定的调控作用,而酚酸是其中起重要作用的一类物质.     

编读往来

2014年1月,我刊收到热心读者沈一骑先生的来信。信中说：“编辑同志,本刊第一期28页有幅‘黄杨’的图片,我在网络上查了黄杨科各属每种植物的图片,包括植物志插图和彩色图片,从形态上看似乎没有与该‘黄杨’一致的,特请教你们和有关专家。此图显示的黄杨与寻常熟知的黄杨形态完全不同;正文中有‘珙桐的东边还有几株黄杨和红豆杉。黄杨属黄杨科常绿灌木或小乔木,主要用于绿化和观赏’,或许作者是指该‘黄杨’为‘用于绿化和观赏’的常见黄杨,是否图片配错了？如果图片是对的,比如是黄杨科中的黄杨属、野扇花属和板凳果属中的某种,那么图片标注应以实际名称为好？如注明‘宜昌黄杨’、‘东方野扇花’或‘顶花板凳果’等,以便于普及植物知识。谢谢！”     

Arbuscular mycorrhizal fungi infection in desert riparian forest and its environmental implications: A case study in the lower reach of Tarim River

This study was conducted on the desert riparian forest along the lower reach of the inland Tarim River, which is located in the arid region of Northwest China. Fifteen plant species in 10 families were collected from five monitoring sections, and examined for the infection ofarbuscular mycorrhizal fungi （AMF）. The impact of different soil factors on AMF infection rate and intensity was compared using the principal component analysis （PCA） method. The results indicate that 11 species are AM and only 4 are non-AM plants. The estimated capacity of AMF infection depends on families of plants and also the parameters （infection rate, infection intensity, fungal spore density） used. The density of fungal spores was relatively higher in Phragmites communis and Populus euphratica in Graminaceae and Salicaceae families, respectively. The infection rate was above 50% in all the AM plants, except Calligonumjunceum. The highest infection rate appeared in Alhagi sparsifolia （97%） and Glycyrrhizainflata （92%）. However, when compared by AMF infection intensity, Tamarix spp. became the top one, followed by Alhagi sparsifolia, and Glycyrrhiza inflata was in the middle range of all the species. The PCA has identified that soil total salt, moisture, organic matter, total nitrogen, total P, available K and pH were closely associated with the AMF infection.     

Selection of adaptive grass and frutex and their planting benefits in the arid-hot valleys of Yuanmou

In view of the environment character of the soil and content of the soil organic carbon, 278 species of grass and frutex were introduced from abroad and China, Some were selected by applied production and plantation benefit investigations. The results showed that： In the arid-hot valleys of Yuanmou the selected species showed the characteristics of fast growth and high yield （38 227.00 kg/hm2）, high nutrition value （CP% content of legu- minous grass and frutex were 22.47%）, as well as the strong ad- versity resistance to high air temperature and arid climate （soil humidity was 3.4%）. The selected species not only effectively meliorated soil and increased fertility, but also improved small environment weather.