水分胁迫下保水剂对爬山虎和廊坊杨苗木水分生理生态特性的影响

通过对藤本植物爬山虎(Parthenocissus tricuspidata)和廊坊杨(Populus langfangensis W.)分别进行保水剂处理和盆栽控水,研究它们的生理、生态学特性。结果表明:廊坊杨加入保水剂后,随水分胁迫的加剧,其叶水势降低的比较缓慢,原生质膜透性被破坏的也较缓慢,叶水势和土壤含水量关系用指数方程拟合较好;爬山虎的叶水势与电导率成周期性降低趋势,叶水势与含水量用4d移动平均趋势线拟合较好;2种苗木都用小颗粒20g处理的使用效果最好。     

五叶地锦抗寒理化指标的四季变化规律

通过对五叶地锦露地越冬处理,测定五叶地锦抗寒理化指标的季节变化,研究其抗寒机制与越冬能力。结果表明,五叶地锦具有一定的抗寒基础;露地越冬后生长表现说明,其在哈尔滨市寒冷的环境中具有一定的越冬能力。     

NaCl胁迫对五叶地锦生长及某些生理特性的影响

用不同浓度的NaCl处理五叶地锦扦插苗 ,研究了盐胁迫对五叶地锦生长及生理特性的影响。结果表明 :小于 5 0mmol·L- 1 的NaCl处理 ,对五叶地锦生长及生理特性没有明显的影响 ;等于或大于 10 0mmol·L- 1 的NaCl处理 ,对五叶地锦的生长有明显的抑制作用 ,而且光合速率、蒸腾速率、气孔导度等生理指标值急剧降低 ,膜相对透性、MDA含量等指标明显增高。由此可以认为 ,10 0mmol·L- 1 NaCl是五叶地锦盐胁迫伤害的阈值。NaCl胁迫下光合作用的下降与膜的伤害、细胞内K 、Ca2 、Na 3种离子平衡关系破坏及糖的反馈性抑制有关 ,而与气孔导度和胞间CO2 浓度无关。盐胁迫下 ,叶片中可溶性糖、脯氨酸以及K、Ca、Na等 3种元素的含量增高。五叶地锦可能通过离子浓度和可溶性糖浓度的提高进行适度的渗透调节 ,以适应NaCl的胁迫。     

Liana habitat and host preferences in northern temperate forests

Lianas and other climbers are important ecological and structural components of forest communities. Like other plants, their abundance in a given habitat depends on a variety of factors, such as light, soil moisture and nutrients. However, since lianas require external support, host tree characteristics also influence their distribution. Lianas are conspicuous life forms in tropical regions, but in temperate areas, where they are less prominent, little is known about factors that control their distributions in these forests. We surveyed the climbing plant species in 20 mature (100 years and greater) forested habitats in the Midwest USA at a variety of levels from simple presence/absence, to ground layer abundances, to those species that had ascended trees. We also examined attributes of the tree species with climbers attached to them. Using cluster analysis, we distinguished five different tree communities in our survey locations. We determined that 25% of the trees we surveyed had one or more lianas attached to it, with Parthenocissus quinquefolia (Virginia creeper) the most common climbing species encountered. Canopy cover and soil attributes both influenced climber species presence/absence and ground layer climber abundance. The proportion of liana species of a given climbing type (roots, stem twiner, tendril climber) was significantly related to the DBH of the host tree, with more root climbers and fewer stem and tendril climbers on large trees. In general, the DBH of climbing lianas had a significant positive relationship to the DBH of the host tree; however this varied by the identity of the liana and the tree species. The greater the DBH of the host tree, the higher the probability that it was colonized by one or more lianas, with tree species such as Pinus banksiana (jack pine) and Quercus alba (white oak) being more susceptible to liana colonization than others. Finally, some liana species such as Celastrus scandens (American bittersweet) showed a preference for certain tree species (i.e., P. banksiana) as hosts. The information obtained about the relationship between the tree and climber community in this study provides insight into some of the factors that influence liana distributions in understudied temperate forest habitats and how lianas contribute to the structure of these mature forests. In addition, these data can provide a point of comparison to other liana communities in both temperate and tropical regions.     

五叶地锦抗逆机制的研究

五叶地锦具有生态适应性强,生长发育快速,抗逆能力突出等特点,是理想的抗逆修复植物。本文结合低温胁迫、盐胁迫、施水量对五叶地锦生理指标的影响,从三个方面阐述了国内五叶地锦逆境生理学研究的现状,以期为五叶地锦在逆境环境中的应用提供理论依据。     

爬山虎多糖的提取与含量测定

建立了石油醚脱脂—70%乙醇除杂—热水提取爬山虎中多糖的工艺,用苯酚—硫酸法测定多糖的含量。实验表明,此方法精密度、稳定性、重现性较好,回收率为98.07%,RSD=3.72%;熟果、茎和叶的多糖平均含量分别为:6.39%、21.88%、11.77%。     

五叶地锦在青海省东部的引种栽培及其园林应用

本文通过五叶地锦在青海省东部的引种栽培试验,结果表明,该品种适宜在本区种植,生长状况良好。同时对该品种的栽培技术要点、园林应用前景做了阐述。     

土壤水分对五叶爬山虎光合与蒸腾作用的影响

 为爬山虎在石漠化荒山植被恢复中的栽培利用提供科学依据。应用英国PPS公司生产的CIRAS-2型光合作用系统,在不同土壤水分条件下测定2年生爬山虎苗木叶片光合与蒸腾速率的光响应特性。结果表明:爬山虎叶片光合速率、蒸腾速率、水分利用效率对土壤水分含量和光合有效辐射强度的变化具有明显的阈值响应。土壤体积含水量在12.6%～20.7%、相对含水量在45.2%～74.3%,爬山虎叶片的光合速率都具有较高水平,其中在体积含水量为18.3%（相对含水量为65.7%）左右时,叶片光合速率和蒸腾速率均达到最高水平,但水分利用效率较低。维持爬山虎叶片具有最高水分利用效率的土壤水分大约在体积含水量为12.6%（相对含水量为45.2%）。维持爬山虎同时具有较高光合速率和水分利用效率的适宜土壤水分范围,在体积含水量为12.6%～18.3%（相对含水量为45.2%～65.7%）之间,超出此范围时,其光合速率与水分利用效率都会明显下降。土壤水分条件适宜时,光合有效辐射强度在400～1000μmol.m-2.s-1之间,爬山虎的光合速率和水分利用效率都能维持较高水平,超出此范围则明显下降。其中最适宜的光合有效辐射强度为800μmol.m-2.s-1左右。所以,爬山虎对光照强度的适应范围较广,具有较强的抗旱性而不适应高土壤水分环境,是适用于干旱瘠薄荒山植被恢复的优良藤本植物。     

酶解法提取爬山虎根皮中白藜芦醇的工艺研究

采用纤维素酶解法提取爬山虎(Parthenocissus tricuspidata)根皮中白藜芦醇,考察酶解温度、酶解时间、酶添加量、乙醇体积分数以及浸提时间对白藜芦醇含量的影响。结果表明,爬山虎根皮中白藜芦醇含量最高,通过单因素试验确定了纤维素酶法提取爬山虎根皮中白藜芦醇的最佳工艺为10 g爬山虎根皮中酶添加量40 mg、酶解时间120 min、40℃条件下60%体积分数的乙醇浸提24 h,测得白藜芦醇含量为59.87 mg/kg。     

不同朝向的五叶地锦对墙体的降温效果及生理机制

研究攀缘植物对墙体的降温作用及生理学机制,为垂直绿化的植物选择及生态效应的定量化研究提供依据,以不同朝向的五叶地锦Parthenocissus quinquefolia为材料,对墙体温度,蒸腾速率,冠层温度,叶片对入射光的反射、透射及以叶绿素荧光参数表示的潜在光能利用能力等指标进行分析。结果表明,不同朝向的五叶地锦对墙体的降温效果存在显著差异,东、南、西、北4个朝向日平均降温值依次为（5.4 ± 0.61）,（3.3 ± 0.48）,（3.1 ± 0.47）和（0.48 ± 0.07） ℃。降温值除受墙体温度（r = 0.879 4）影响外,和蒸腾速率（r = 0.770 3）、冠层温度（r = 0.645 8）和透射率（r = 0.504 4）及叶绿素荧光参数F₀（r = 0.475 8）等生理生态指标存在显著的正相关关系。同时表明,五叶地锦不适于北向墙体绿化。因此,在垂直绿化选择植物种时,应同时考虑植物的蒸腾速率及其对光的反射、透射及利用能力。图1表5参20