杨树

The resistance of different species of poplar to canker disease in different 9 poplar species were tested.

对此病的抗性，不同杨树品种之间存在着差异。本试验选取了9种杨树进行试验。

Poplars are one of the most important deciduous trees in the world. China is rich natural resource of poplars.

杨树是世界上广泛栽培的重要造林树种之一，我国是世界上杨树资源丰富的国家。

Endophyte could control plant diseases and insect pests of Populus .

对杨树的内生真菌进行研究可为开发内生真菌防治杨树病虫害提供基础。

Beijingensis under three droughttreatments, normal, moderate and severe stresses. The results showed:(1) the canker disease ofboth cultivars was serious gradually with increased drought;(2) the bark tissue cells sufferedplasmolysis, more evident with the severity of drought stress;(3) under the drought andinoculation with B. dothidea, cells of two cultivars damaged at different degree, mailyrepresented in the changes of organelles, such as chloroplast swollen and distorted, number ofmitochondria increased and membrane system indistinct; then organelles suffered furtherdamagement with inoculation time, thinned mitochondrias stroma, decreased cristae, crumpledand partly broken membrane of chloroplasts with stroma exosmosis. At last, the chloroplastspartly disorganized;(4) the hyphae growed mainly intercellular in resistant cultivar and notonly intercellular but also intracellular in susceptible cultivar, which directly caused thenecrosis of cells;(5) under the severe drought, the damage of cells enhanced the infection ofpathogen and drought and pathogen stressed together and promoted the disease development;the damage from pathogen on cells was more serious than that from drought.

结果显示：(1)随着干旱胁迫程度的增加，2种杨树溃疡病害发生渐趋严重；(2)干旱胁迫下，杨树树皮组织细胞发生质壁分离，并随胁迫程度的增加而严重；(3)干旱胁迫下接种病原菌，2种杨树细胞发生不同程度的损伤，主要表现为细胞器发生较大变化，如出现叶绿体肿胀变形、线粒体数量增多，质膜模糊不清等现象；随接种时间的延长，细胞器受到进一步损伤，叶绿体被膜折皱，严重时局部破裂，基质外渗，并部分最终解体；(4)毛白杨中的菌丝主要在细胞间隙中穿行，而北京杨的菌丝除在细胞间隙中生长之外，侵入细胞内部也较多，直接导致细胞的解体；(5)干旱胁迫下细胞的损伤促进了病原菌的侵染，干旱和病原菌的双重胁迫加剧了病害的发生程度，并且病原菌侵染对细胞的破坏程度大于水分胁迫。

The Tulip Tree is not a poplar, but it is still commonly referred to as Tulip poplar, Hickory poplar, White poplar and Yellow poplar.

郁金香树不是杨树，但它仍是俗称为郁金香杨树、胡桃木杨树、白杨、黄杨树。

The inducing of Dothiorella gregaria cell wall degradation product-oligosaccharides to the resistant index of poplar cell were studied with the poplar callus.

以杨树愈伤组织为试验材料，研究了杨树溃疡病菌细胞壁裂解物——低聚糖对杨树细胞有关抗病指标的诱导作用。

Poplar belongs to Salicaceae, Populus. There are more than one hundard kinds in the world, while more than fivty-seven in China. So, poplar is more important than other trees for not only protecting ecology but also advancing country economy development.

杨树属杨柳科，杨属，全世界杨树有100多种，而我国就有57种之多，因此无论对于生态还是对国民经济的促进作用，杨树都起着其它树种所无法比拟的作用。

The results showed that endophytes varied in quantity,population distribution,and dominance in different tissues,regular changes showed in species...

结果表明：杨树不同部位内生真菌在数量、种群分布和优势种群方面都存在着一定的差异；不同年龄段杨树内生真菌的种类和数量发生规律性变化；不同地理分布区杨树内生真菌的数量和种群组成存在差异，但又呈现一定的规律性。

Cd inhibited the absorption of Mg and Mn in roots. However, Cd could stimulate the absorption of Fe in roots. Moreover, Cd inhibited the absorption and utilization Mg, Mn and Fe in leaves. 4. Cd inhibited the photosynthesis of Populus clones. Cd showed no significant inhibition to net photosynthesis rate, stomal conductivity and transpiration rate versus the control, under 10μM Cd treatment.

Cd胁迫还对杨树光合作用产生影响，低浓度Cd对杨树光合速率无影响，中高浓度Cd对杨树净光合速率、气孔导度和蒸腾速率等具有抑制作用，而且随着处理时间的延长和Cd胁迫浓度的提高而逐渐加大。

Poplar(Populus cv.I4551 from France and Populus deltoids cv.I-69/55 from China) was chosen as plant material,because poplar is known to have a characteristic tension wood with G-layer and to produce a high longitudinal stress.

本研究选择杨树(从法国采的Populus cv.I4551和从中国采的Populus deltoids cv.I-69/55)作为实验材料，因为杨树中很容易产生有胶质纤维的应拉木并伴有大的纵向生长应力；另外，杨树也是一个在全球都非常重要的速生人工林树种。

Do you know, i need you to come back

你知道吗，我需要你回来

Yang yinshu、Wang xiangsheng、Li decang,The first discovery of haemaphysalis conicinna.

1〕 杨银书，王祥生，李德昌。安徽省首次发现嗜群血蜱。