松材线虫和拟松材线虫不同株系酶电泳的研究*

应用聚丙烯酰胺凝胶电泳技术对来自国内及日本、加拿大、法国、挪威的松材线虫及拟松材线虫株系作酶电泳的初步分析。结果表明，不同株系的苹果酸脱氢酶及纤维素酶酶谱各不相同。超氧化物歧化酶有１条在不同株系中迁移率相同的酶带。松材线虫与拟松材线虫在酯酶谱上差异明显，但培养于裂褶菌、多毛孢和葡萄孢上的来自南京黑松上的同一株系线虫的酯酶谱也显示了明显差异，表明了该酶的不稳定性。谷氨酸草酰乙酸转氨酶是唯一可区分两种线虫的酶，松材线虫只有１条迁移率０．３９的带，拟松材线虫只有１条迁移率０．５１的带，可用于两种线虫的生化鉴定。对可溶性蛋白质及过氧化物酶的分析，未检测到清晰可辨的酶带。     

松材线虫与拟松材线虫可溶性蛋白的比较

采用聚丙烯酰胺凝胶垂直板型电泳法,分析了松材线虫和拟松材线虫的可溶性蛋白.从电泳图谱蛋白带数、迁移率等方面的比较,两线虫可溶性蛋白的电泳图谱差异不明显,相互间不存在可见的特异性蛋白.     

大岗山人工针阔混交林与常绿阔叶林水文动态变化研究

对松材线虫 7个株系和拟松材线虫 2个株系的线粒体DNA随机扩增多态性分析结果显示 ,松材线虫和拟松材线虫种间和种内都表现出很大的变异性 ,但种间变异明显大于种内变异 ,因而支持将松材线虫和拟松材线虫划分为两个不同的种。两个拟松材线虫株系 (法国株系和日本株系 )之间的相似值和松材线虫各株系间的相似值极为接近 ,由此看来 ,这两个株系的变异为种内变异 ,应同属于一个种。聚类分析的结果表明 ,松材线虫和拟松材线虫系两个明显不同的类群 ,即松材线虫类群和拟松材线虫类群。松材线虫类群又分为两个亚组 ,一个是以日本株系为代表 ,另一个是以北美洲 (美国和加拿大 )株系为代表     

松材线虫和拟松材线虫不同株系线粒体DNA RAPD分析

对松材线虫7个株系和拟松材线虫2个株系的线粒体DNA随机扩增多态性分析结果显示,松材线虫和拟松材线虫种间和种内都表现出很大的变异性,但种间变异明显大于种内变异,因而支持将松材线虫和拟松材线虫划分为两个不同的种.两个拟松材线虫株系(法国株系和日本株系)之间的相似值和松材线虫各株系间的相似值极为接近,由此看来,这两个株系的变异为种内变异,应同属于一个种.聚类分析的结果表明,松材线虫和拟松材线虫系两个明显不同的类群,即松材线虫类群和拟松材线虫类群.松材线虫类群又分为两个亚组,一个是以日本株系为代表,另一个是以北美洲(美国和加拿大)株系为代表.     

（拟）松材线虫耐久型四龄幼虫（LⅣ）的形态及其分化变异

本文对浙江省宁波市松材线虫病疫区内的松材线虫和拟松材线虫的耐久型四龄幼虫(LⅣ)的形态及其分化变异作了观察研究.结果表明,松墨天牛成虫体内携带的松材线虫和拟松材线虫的LⅣ在形态上完全相同;同一来源的(拟)松材线虫的LⅣ既可发育形成松材线虫,也可形成拟松材线虫.它的分化变异结果受寄主等环境因子影响,规律是:带尾尖突的LⅣ离开松墨天牛成虫进入黑松多变为无尾尖突的松材线虫;进入马尾松多变为带尾尖突的拟松材线虫.     

松材线虫和拟松材线虫繁殖能力差异研究

松材线虫作为外来入侵种,逐步取代拟松材线虫占据生态位。初步研究表明这可能与两种线虫的繁殖能力差异关系密切。本研究采取了两种方法,即离体条件竞争试验和体内竞争试验比较二者繁殖力。结果表明,松材线虫的繁殖水平明显高于拟松材线虫。松材线虫和拟松材线虫混合物长时间培养后,松材线虫逐步竞争淘汰拟松材线虫。除此以外,离体培养和体内竞争结果均表明,竞争条件下松材线虫的繁殖力高于非竞争条件。     

松材线虫与拟松材线虫杂交试验及后代繁殖力研究

松材线虫Bursaphelenchus xylophilus和拟松材线虫B.mucronatus是伞滑刃属内两个独立的种,均可引起松材线虫病。松材线虫与拟松材线虫能否进行种间杂交在学术界一直存在争议。采用4个虫株在实验室条件下开展了杂交试验及杂交后代繁殖力研究。结果表明:实验室条件下松材线虫和拟松材线虫可成功杂交,他们之间未发展出严格的生殖隔离,二者极可能来源于同一祖先。     

基于TaqMan实时荧光PCR的拟松材线虫分子鉴定技术

拟松材线虫与松材线虫的亲缘关系极为接近,是松材线虫病病原鉴定的主要干扰物种。为了排除松材线虫病病原鉴定过程中拟松材线虫的干扰,采用TaqMan实时荧光PCR技术,以核糖体DNA内转录间隔区(ITS)为模板设计拟松材线虫特异性引物和TaqMan探针,开展拟松材线虫分子检测和鉴定技术研究。结果表明:拟松材线虫ITS2区域存在较多的碱基差异,以此为模板设计的拟松材线虫引物和TaqMan探针组合具有较强的特异性;该组合灵敏性高,能够实现对拟松材线虫单条线虫甚至单个卵的分子检测和鉴定。结合现有的松材线虫分子鉴定技术,可以为进一步构建松材线虫双重检测技术体系奠定基础,为林业和海关检疫提供可靠的技术支撑。     

松材线虫和拟松材线虫不同株系致病性的研究*

１９９０－１９９３年，从国内外收集的松材线虫９个株系和拟松材线虫５个株系，用皮接法接种３－６年生的松苗，测定线虫的致病性。结果表明，松材线虫的致病力明显高于拟松材线虫，其中国内的５个株系致病力最高，拟松林线虫通常不致病或致病力极低，在同一线虫种内，株系间致病力随寄主不同而不同。在寄主死亡速度上，寄主相同并死亡率相同或相近时，采自南京、广东马尾松病树上的线虫株系接种后，寄主平均死亡时间略短于其它株系     

松材线虫与拟松材线虫分泌的纤维素酶系研究

采用羧甲基纤维素钠(CMC)、微晶纤维素(MC)和水杨素(SC)三种底物,用刚果红染色法和DNS法分别定性和定量分析了松材线虫和拟松材线虫分泌物中纤维素酶系组分和酶活力.结果表明,松材线虫和拟松材线虫分泌物中存在完全降解纤维素所需的3种酶系组分:内切-β-1,4-葡聚糖酶、外切-β-1,4-葡聚糖酶和β-葡萄糖苷酶,松材线虫分泌物中三种酶活力明显高于拟松材线虫酶活力.研究结果为更好的解释松材线虫致病机理提供了科学数据.     

杏树品种过氧化物同工酶数量分类的研究

采用聚丙烯酰胺凝胶垂直板电泳系统,对河南早熟杏和桃杏１０个品种进行了过氧化物同工酶的测定。其结果表明,杏树酶谱具多态特性,其主导酶谱Ｒｆ为０４４～０４５;每个品种均有特征酶谱（Ｒｆ）,或以酶带数目、宽度、活性强弱相区别。同时,采用排序方法及系统聚类分析方法,对杏树１０个品种的过氧化物同工酶酶谱的相似程度进行研究结果发现：两种方法研究的结果与其酶谱分类、形态分类非常吻合,从而为杏树品种的鉴定与检验及其合理划分,提供了新的依据和手段。     

Differential effects of vegetation restoration in Mediterranean abandoned cropland by secondary succession and pine plantations on bird assemblages

Two contrasting trajectories for vegetation restoration in agricultural landscapes are secondary succession following cropland abandonment that can regenerate woodlands (passive restoration) and conversion of cropland to tree plantations (active restoration), which have mostly focused on pine species in the Mediterranean Basin. We compared the effects of these two contrasting trajectories of vegetation restoration on bird assemblages in central Spain. Vegetation structure differed in the two restoration trajectories, pine plantations attaining higher tree cover and height (31% and 4.1 m, respectively) but lower strata complexity than secondary shrubland and holm oak woodland (which attained 10% and 1.4 m of tree cover and height, respectively). Bird species richness differed in stands under active or passive restoration trajectories, the former collecting a higher total number of species (4.2 species per 0.78 ha plot) than the latter (3.5 species per plot). The number of forest species increased with vegetation maturity in both restoration trajectories, but especially in stands under active restoration. The occurrence of woodland generalist species increased and of species inhabiting open habitats decreased in actively restored stands, being some of these latter species of high conservation priority in the European context but relatively common at the regional level. Bird species inhabiting pine plantations had broader habitat breadth at the regional level than those inhabiting secondary shrublands and woodlands. Maximum regional density did not differ between both restoration trajectories, but it increased with development of the herbaceous layer only at the secondary succession trajectory. The relative importance of species of European biogeographic origin was higher in mature pine plantations (58.9% of total bird abundance) than in mature holm oak woodlands (34.4%), whereas that of Mediterranean species was considerably higher in the latter (40.1%) than in the former (20%). Bird assemblages of relatively small patches of pine plantations are unable to reflect the regional avifauna, in contrast with the relationships between local and regional assemblage characteristics that can be found in isolated natural forests. We conclude that programs of vegetation restoration should base upon a range of approaches that include passive restoration, active restoration with a variety of tree and shrub species, and mixed models to conciliate agricultural production, vegetation restoration and conservation of target species.     

油桐属与石栗属叶绿体的核酸、蛋白质及超微结构的初步研究

叶绿体超微结构是叶绿体形态和功能的重要内容之一。叶绿体除在光合作用中具有重要的功能外,在高等植物细胞质遗传中,作为细胞器也具有重要的作用。据估计,叶绿体DNA的信息量足以编码分子量为40000道尔顿的多肽约150—300个。不同种的叶绿体蛋白质存在差异。不同品种的叶绿体显微结构也存在明显差异。前文已发现油桐属和石栗属在叶片的核酸、蛋白质以及叶绿素含量上存在明显差异。本文试图对该两属的叶绿体超微结构及核酸和蛋白质含量进行比较研究,以提供进一步依据。     

秃叶黄皮树和黄檗种子萌发习性的比较

对秃叶黄皮树和黄檗种子进行了种子形态、种皮透水性、发芽率等方面的比较研究。结果表明：种皮对秃叶黄皮树和黄檗种子的透水性有较大影响，前者透水性较后者好；秃叶黄皮树种子的田间发芽率为68．7％，极显著高于黄檗的36．3％；秃叶黄皮树种子和黄檗种子具有休眠特性，且秃叶黄皮树种子的休眠较黄檗浅，经过低温层积后两种种子的萌发率都有所提高。     

红棕象甲、双钩异翅长蠹二种有害生物在贵州的风险分析

运用有害生物危险性分析方法,对红棕象甲Rhychophorus ferrugineus(Olivr)、双钩异翅长蠹Hetero-bostrychus aequalis(Waterhouse)在贵州的潜在危险性进行了定性、定量分析。结果表明,红棕象甲其R值为2.05属于高度危险的有害生物,双钩异翅长蠹其R值为1.99属于中度危险有害生物,应采取强制性检疫措施,防止其传入、扩散危害。     

“金丝油桐”与贵桐2号的过氧化氢酶同工酶谱

为了从生化水平上鉴别"金丝油桐"的品种,利用SDS-聚丙烯酰胺凝胶电泳技术,分析了湖北省来凤县"金丝油桐"与贵桐2号叶的过氧化氢酶同工酶谱,结果显示:"金丝油桐"有11条酶带,其中a、b、f、i、l这5条酶带颜色较深,很清晰,而c、e、g、h、j、k这6条酶带颜色较浅;贵桐2号共有13条酶带,其中a、b、f、i这4条酶带颜色很深,而c、d、e、g、h、j、k、l、m这9条酶带颜色较浅;贵桐2号的酶带比"金丝油桐"多出d、m这2条;"金丝油桐"11条酶带的Rf值依次为0.20、0.36、0.37、0.43、0.46、0.50、0.52、0.59、0.68、0.76、0.90;贵桐2号13条酶带的Rf值依次为0.20、0.36、0.37、0.39、0.43、0.46、0.51、0.52、0.60、0.69、0.77、0.88、0.95。分析结果表明:"金丝油桐"与贵桐2号这2个品种间存在着亲属关系,但其差别较大。     

Restoration of oak forest: Effects of former arable land use on soil chemistry and herb layer vegetation

Abstract

Stands of pedunculate oak (Quercus robur) planted 50–80 years ago on two types of land (previously forested land and former arable fields) were compared regarding vegetation and soil. Former arable soils were characterized by a higher pH, higher nitrate concentration and higher soil density, but had lower organic matter content and lower ammonium concentration in the topsoil (0–5 cm). These differences, however, decreased with soil depth. Phosphorus concentration was consistently higher in former fields throughout the soil profile (0–45 cm). Nitrogen mineralization, determined by in situ incubation, showed a strong seasonal pattern with peak values in spring. Non-metric multidimensional scaling ordination revealed marked compositional differences in the vegetation between the two land-use categories, and also compositional turnover along gradients in soil pH and nitrogen availability. Differences in soil pH between land-use categories occurred in a range critical for the establishment of many typical forest herb layer species. Plant indicator species were identified for the two land-use categories. The results showed that acid-sensitive forest herbs may benefit from the higher pH soils in new woodlands, in contrast to ancient forest soils with little buffer capacity towards natural and anthropogenic acidification. In conclusion, former arable use has long-lasting effects on soil properties and vegetation composition in broadleaved forests. New woodlands on former fields can thus offer relatively persistent new habitats for acid-sensitive species that have suffered from reduction in habitat area during historic periods of deforestation and cultivation.     

盐胁迫对尖果沙枣和大果沙枣膜脂过氧化和渗透调节的影响

用0％、0.4％、0.8％、1.2％4种浓度NaCl溶液处理大果沙枣(Elaeagnus moorcroftii)和尖果沙(E.oxycarpa)枣幼苗,盐胁迫7、14、21、35d后分别测定4种处理条件下大果沙枣幼苗和尖果沙枣幼苗叶片中可溶性糖和丙二醛的含量,研究盐胁迫对沙枣膜脂过氧化和渗透调节的影响.结果表明:①0.4％NaCl溶液处理和0.8％NaCl溶液处理的两种沙枣幼苗叶片中MDA浓度前期(尖果沙枣21d内,大果沙枣7d内)增幅较小,但随着胁迫时间的延长,MDA浓度增幅变大,1.2％NaCl溶液处理的两种沙枣幼苗叶片中MDA含量最高;②两种沙枣幼苗0.4％、08％、1.2％三个NaCl溶液处理叶片中可溶性糖含量都高于对照水平.     

乳源木莲与红花木莲苗期动态生命表

乳源木莲 (Manglietiayuyuanensis)和红花木莲 (Manglietiainsignis)均为木兰科 (Magnoliaceae)木莲属 (Man glietia)常绿阔叶乔木树种 ,生长迅速 ,树干通直 ,其木材纹理通直 ,结构细密 ,有光泽、香味 ,心材耐腐 ,不翘不裂 ,加工容易 ,是优良的装饰用材和胶合板材树种 ,也是世界上现有被子植物中原始类群的孑遗植物 (张维珍 ,1989;邱以祥 ,1991;1994 ) ,是我国北纬 34°以南 ,经济价值很高的珍稀濒危树种之一 ,对古植物学和植物系统发生学有重要的科研价值 (张维珍 ,1989)。其根、叶、花、果均为优等药材 (张维珍 ,1989;邱以祥 ,1991;1994…     

周山森林公园不同林木生长对土壤氮的动态影响

在河南洛阳周山森林公园,2009年不同时期对紫叶李(Prunus cerasifera Ehrhart)和塔柏(Sabina chinensis)不同立地林地土壤全氮含量进行了测定,结果表明:紫叶李林地土壤中全氮的含量高于塔柏林地含量,无论平地坡地皆是如此。在不同月份或季节,前者全氮的含量高于后者,且波动幅度较后者大。同时土壤中全氮含量也受地形的影响,平地的全氮含量高于坡地。不同深度,0~10cm土层,平地和坡地的差距最大,随着土层深度的增加,差距逐渐缩小,20~30cm土层,已无明显差异。总体来看,紫叶李平地和坡地土壤氮元素的含量变化要比塔柏平地和坡地土壤氮元素含量变化显著。