Determination of drought tolerance using root activities in Robinia pseudoacacia ''Idaho'' transformed with mtl-D gene

Idaho locust (Robinia pseudoacacia 'Idaho') is an exotic multi-purpose tree used in landscaping, soil and water conservation, fodder sources and others. To improve its drought tolerance for reclaiming arid land, five lines of transformed mtl-D gene, as osmotic regulator in plant cells, have been selected and managed to determine their drought tolerance under experimental conditions.Qualitative and quantitative variables of transformed plants were studied. The critical value of drought tolerance was determined by detecting the 2,3,5-triphenyl tetrazolium chloride (TTC) reductants in roots and soil water content (SWC). The critical value for drought tolerance was SWC 6% while for the control plants the critical SWC was 8%; a moderate level of SWC is 13% and the highest SWC for plant endurance was 18%. The method proved to be reliable and sensitive in the evaluation of drought tolerance for forest trees.     

刚毛柽柳 TheIF1A 基因的互作蛋白及其表达模式分析

翻译起始因子是一类翻译起始所必需的特异蛋白因子,前期研究表明柽柳翻译起始因子 (TheIF1A) 基因能对外界盐和干旱等非生物胁迫做出响应,且过表达 TheIF1A基因能提高酵母和烟草的抗旱耐盐能力。为进一步研究TheIF1A基因的抗逆机制,本研究通过酵母双杂交对柽柳翻译起始因子(TheIF1A) 基因的互作蛋白进行了筛选,共获得5个互作蛋白,分别为RNA聚合酶β II亚基 (RNA polymerase beta II subunit)、ATP合成酶CF1α亚基蛋白 (ATP synthase CF1 alpha subunit protein)、细胞色素b6/f 复合物亚基IV(cytochrome b6/f complex subunit IV)、核酮糖1,5-二磷酸羧化酶/加氧酶小亚基蛋白(ribulose 1,5-bisphosphate carboxylase/oxygenase small subunit)和组蛋白乙酰转移酶(histone acetyltransferase)。利用实时荧光定量PCR对这5个蛋白基因及 TheIF1A 基因在盐和干旱胁迫处理下的表达模式进行分析,结果表明:这些蛋白基因在盐和干旱胁迫下的表达模式与 TheIF1A基因基本一致,表明TheIF1A可能通过与这些蛋白相互作用来参与逆境胁迫应答。为进一步研究TheIF1A 基因的抗逆机理奠定了基础,有利于完善林木抗逆机制的研究,并为通过基因工程手段提高林木抗逆性提供了候选基因。     

8个中山杉新无性系耐盐力的水培试验研究

用水培法对8个中山杉新无性系进行不同质量分数氯化钠液处理,以相对生长量(RG)、盐害指数(SI)和相对电导率(RL)为指标,进行耐盐力评估。经聚类分析和相关性分析,结果表明:在水培条件下,不同无性系的耐盐力达0.30%~0.45%。中山杉118号具有较好的耐盐性,耐盐力为0.4%~0.45%;中山杉136号、1号、146号和149号耐盐力中等,为0.35%~0.40%;而中山杉102号,27号和24号的耐盐性较差,为0.3%~0.35%。RG与RL以及RG与SI两两均呈极显著负相关,RL和SI之间呈极显著正相关。相对生长量、盐害指数和相对电导率均可作为中山杉耐盐能力综合评价指标。     

Evaluation of Dutch elm disease susceptibility and pathogenicity of Ophiostoma ulmi using micropropagated elm shoots

Elm (Ulmus sp.) shoots from in vitro micropropagated plants were tested with Ophiostoma ulmi culture filtrates, at different dilutions to determine the susceptibility of different host clones to Dutch elm disease (DED). ‘Commelin’, a susceptible Dutch hybrid, showed a high wilting index but that of American elm was higher. Although U. pumila × japonica (Sapporo gold 2) was the most tolerant to spore inoculation, its wilting index was as high as that of ‘Commelin’. The absorption capacity and wilting index of the elm shoots showed consistent correlation to isolate effectiveness (as determined by inoculation experiments), to production of toxin (cerato-ulmin) and to filtrate dilution. This method could be used to assess the effectiveness of the different O. ulmi isolates and for the detection of elm genotypes that are highly susceptible to Dutch elm disease.     

外源水杨酸对盐胁迫下苦菜抗氧化系统的影响

以苦菜为试验材料,研究了5 mmol/L水杨酸（SA）预处理后,苦菜幼苗分别在0.6%、0.8%、1.0%NaCl溶液胁迫下5、10、15、20、25 d时抗氧化系统的变化。研究结果表明,5 mmol/L SA处理提高了盐胁迫下苦菜幼苗细胞SOD、POD的活性,抑制了CAT的活性;在盐胁迫处理后10、15 d,苦菜细胞内脯氨酸和H2O2含量分别达到峰值,并显著高于清水对照,说明SA通过诱导H2O2含量增加,提高抗氧化酶活力,缓解盐胁迫伤害,提高苦菜耐盐性。     

Cold tolerance of Acacia karroo and A. nilotica, two tree species from South Africa, in Beijing

Fynbos plant communities developed under geographic and climatic conditions unique to South Africa. Acacia karroo is the most widespread tree species, well known for its drought tolerance. A. nilotica exudes a good quality gum which is edible and suitable for confectionery. The two species have been introduced to China but little is known about their adaptability under the new environmental conditions. For our present study, the growth potential and physiological and biochemical parameters of the two species in response to cold stress were investigated. The results, measured as seed qualities (purity, thousand seed weights, germination, etc.) show differences between A. karroo and A. nilotica. The seed germination rate was between 10% and 60%. Seedlings were established in fields, pots and plugs. Those in the field grew well during the growing season but completely died in the winter. Those in pots or plugs were moved to and managed in the greenhouse. The plants were green in winter. The electrical conductivity of cells, the contents of water soluble sugars, proteins, malondialdehyde (MDA) increased during eight hours of low temperature treatment at 4℃. The activities of superoxide dismutase (SOD), peroxidase (POD) and catalase (CAT) decreased markedly during the eight hours of 4℃treatment. We conclude that A. karroo and A. nilotica have little adaptability to the cold winter weather and cannot survive in the outdoors in the Beijing area, but could grow well indoors as ornamentals.     

竹木复合胶合板二次覆面工艺研究

针对目前国内竹胶合板建筑模板普遍存在厚度公差大、表面质量差等严重影响产品质量的问题，进行了竹木复合和二次覆面工艺的探索。研究结果表明：产品厚度公差和表面质量以及主要物理力学性能达到或超过竹胶合板模板JG／T156—2004标准优等品质量要求。     

Incorporating forage grasses in riparian buffers for bioremediation of atrazine, isoxaflutole and nitrate in Missouri

Multi-species tree-shrub-grass riparian buffer systems have been recognized as one of the most cost-effective bioremediation approaches to alleviate nonpoint source agricultural pollution in heavily fertilized systems. However, highly concentrated herbicides in surface and subsurface water and shade cast by trees along the stream bank usually compromise the effectiveness of these systems. Greenhouse trials and field lysimeter studies were conducted to evaluate the tolerance of orchard grass (Dactylis glomerata), smooth bromegrass (Bromus inermis), tall fescue (Festuca arundinacea), timothy (Phleum pratense), and switchgrass (Panicum virgatum) ground covers to atrazine and Balance™ (isoxaflutole) plus their capacity to sequester and degrade these herbicides and their metabolites. Their ability to remove soil nitrate was also quantified. Concentrations of atrazine, Balance™ and their metabolites in the leachate, soil and plant samples were determined by solid phase extraction followed by high performance liquid or gas chromatographic analyses. Distribution of the herbicides and metabolites in the system was calculated using a mass balance approach. Herbicide bioremediation capacity of each lysimeter treatment was determined by the ratio of metabolites to parent herbicide plus metabolites. Bioremediation of nitrate was quantified by comparing nitrate reduction rates in grass treatments to the bare ground control. Based on this herbicide tolerance, bioremediation data and shade tolerance determined in a previous study, it was established that switch grass, tall fescue and smooth bromegrass are good candidates for incorporation into tree-shrub-grass riparian buffer systems designed for the bioremediation of atrazine, Balance™ and nitrate.     

日本厚朴防寒技术研究

以日本厚朴引种实生苗为试材,综合引种过程中日本厚朴的越冬表现,分析不同越冬防护措施与植株冻伤率、生长状况之间的关系,探讨沈阳地区引种日本厚朴栽培的最佳方式和越冬防寒措施,制定适宜的栽培管理方法,解决日本厚朴在北方地区自然条件下安全越冬的问题.     

Construction of cDNA Library from Populus euphratica

1 Introduction Populus euphratica is a salt tolerant tree species, which is mainly distributed in the desert regions in northwest China (Wei 1993). Moreover, it is the only large tree species, which can survive and develop into forest in these arid and saline-alkali areas. P. euphratica forest plays a very important role in restraining the expansion of desert, maintaining ecological environment in west China, protecting the biological diversity and raising the local people抯 living standard…