刺五加繁殖生态学研究生殖配置(英文)

在东北林业大学帽儿山生态站的天然次生林里（４５°２３′～４５°２６′Ｎ，１２７°３６′～１２７°３９′Ｅ）对刺五加的生殖配置进行研究，发现刺五加每年分配给有性繁殖的能量和无性繁殖的能量与植物总能量的百分比分别是年龄的幂函数，只是幂指数不同，ｂ有性＝０．８７４０，小于１；ｂ无性＝２．１９９２，大于１．这种关系表明在样本覆盖的年龄范围内（５～１５年），刺五加分配给无性繁殖的能量逐年递增得较快，分配给有性繁殖的能量逐年递增得较慢．由此可以推测林下刺五加随着林分稳定性增加，逐渐以无性繁殖为主．根据研究结果，建议在天然次生林下对刺五加进行采挖时不要把根茎全部取走，应留下一部分，使其保持天然更新的能力．同时，对根茎需要适当切割，促进芽转化为无性小株，有利于更新     

杨树与溃疡病菌互作中过氧化物酶的细胞化学定位

为了从细胞水平上研究过氧化物酶在杨树与溃疡病菌互作过程中的作用、过氧化物酶在细胞器中的定位与活性变化,以及过氧化物酶在杨树与溃疡病菌互作中的机制,该文以抗性不同的毛白杨(高抗种)和北京杨(高感种)为研究材料接种溃疡病菌葡萄座腔菌,利用DAB细胞化学染色技术研究过氧化物酶在细胞中的分布及活性。通过分析酶活性区域的电子密度发现:无论抗病种还是感病种,接种后均发现细胞中有过氧化物酶活性反应;抗病种过氧化物酶活性不仅明显高于该种未接种的对照,也明显高于接种处理后的感病种,并且定位更广泛,在细胞壁、细胞间隙、叶绿体膜、线粒体膜及质膜上均有大量定位;感病种酶反应产物主要分布于细胞壁上,在质膜、局部核膜上有少量定位,且定位范围及强度均小于抗病种。      

美国凌霄光合生理参数对水分与光照的响应

该文利用CIRAS -2型便携式光合作用仪测定了不同土壤湿度下3年生美国凌霄叶片净光合速率（Pn）、蒸腾速率（Tr）、水分利用效率（WUE）及光能利用效率（LUE）等生理参数的光响应过程,阐明了其光合生理参数对土壤湿度和光照强度的响应规律,探讨了美国凌霄正常生长发育所需的土壤水分和光照条件。结果表明:美国凌霄的Pn、Tr、LUE及WUE对土壤湿度和光照强度的变化具有明显的阈值响应。①采用非直角双曲线模型进行模拟光响应过程较好,光响应曲线曲角接近于1。随着质量含水量Wm (5.5％～19.4％)、相对含水量Wr（20.1％～71.1％）的递增,光补偿点降低,光饱和点、最大净光合速率及表观量子效率均升高。在Wm为19.4％时,光补偿点最低(21.61 μmol/（m2·s）),光饱和点最高(1 400 μmol/(m2·s))。②维持美国凌霄正常生长、同时具有较高Pn、LUE及WUE的土壤湿度范围,在Wm为13.5%～19.4%（Wr为49.5%～71.1%）之间,最佳土壤湿度的Wm为19.4%（Wr为71.1%）,正常生长的最低土壤湿度Wm为7.7%（Wr为28.2%）。③美国凌霄对光照环境的适应性较强,在光合有效辐射强度为800～1 600 μmol/(m2·s)范围内,Pn和WUE都具有较高水平,饱和光强大约在800～1 400 μmol/(m2·s)之间,LUE在100～300 μmol/(m2·s)光强范围内达到峰值。      

The effect of total carbon on microscopic soil properties and implications for crop production

Soil structure is a dynamic property affected by physical, chemical, and microbiological processes. Addition of organic matter to soils and the use of different management practices have been reported to impact soil structure and crop production. Moderation in soil temperature and increases in microbial activity and soil water retention are often suggested as reasons for the rise in crop yield when organic matter is added to the soil. Less is known about the direct effect of changes in soil structure on crop production. A field experiment was conducted to study the effect of summer cover crop and in-season management system on soil structure. The experiment was a nested design with summer cover crop as the main plot and management system as the subplot. Summer cover crop treatments included cowpea (Vigna unguiculata L. Walp.) incorporated into the soil in the fall (CI), cowpea used as mulch in the fall (CM), sudangrass (Sorghum vulgare) incorporated into the soil in the fall (S), and dry fallow or bare ground (B). Management systems were organic (ORG) and conventional (CNV) systems. Lettuce (Lactuca sativa L.) and cantaloupes (Cucumis melo L.) were cultivated in rotation in the plots for three consecutive years using the same cover crops and management systems for each plot. Disturbed and undisturbed soil cores were collected at the end of the third year and used for laboratory experiments to measure physical, chemical, and hydraulic properties. Image analysis was used to quantify soil structure properties using a scanning electron microscope on thin sections prepared from the undisturbed soil cores. We found that total soil carbon was correlated with porosity, saturation percentage, and pore roughness. Pore roughness was correlated with crop production in general and with marketable production in particular. We found that the higher the complexity of the pore space, the more water retained in the soil, which may increase soil water residence and reduce plant water stress.     

3种药剂对稻水象甲大田防治作用研究

本文开展了吡虫啉10%可湿性粉剂、阿维菌素2%乳油和三唑磷20%乳油等3种常见药剂对检疫性害虫稻水象甲的大田防治作用研究,试验结果表明,供试药剂对稻水象甲成虫均具有较好的防效,药后7d防效依次为94.58%、98.67%和100%。综合考虑,推荐阿维菌素2%乳油或吡虫啉10%可湿性粉剂为湖南防治稻水象甲的较理想药剂。     

新的东北地区木本植物信息检索方法

以东北地区常见的399种木本植物作为研究对象,统计分析4本植物分类学著作中的物种描述信息,选取了29个各著作中植物描述普遍共同关注的方面作为检索项,并从检索的角度对物种的描述进行了归纳整理,经因子分析和检索项两两对比分析证明选取的29个检索项可以完成对所选木本植物的检索.提出了一种新的检索项权重赋值方法,并利用权重值优...     

Anatomical and morphological characteristics of Populus euphratica in the lower reaches of Tarim River under extreme drought environment

Populus euphratica Oliv.is an old desert tree species that has been naturalized and invades zones along the watercourses in many arid and semiarid regions.The plant species developed some plasticity to adapt to the gradual environmental gradients.The aim of this study was to test the hypothesis that the changes in leaf morphology of P.euphratica reflect the adaptability of the plant to the unique environment of the lower reaches of Tarim River in China.The foliar architecture,blade epidermal and internal anatomies of P.euphratica were analyzed at different sites along the Tarim River.Compared with the abaxial surface of the leaves,their adaxial surface has more hairs,a greater stomatal density and opening,higher mesophyll proportion,and increased blade thickness,palisade width,and epidermal thickness.The long trichome of the roots found at site 6 in the Yinsu section may be an adapted structure of the plants in arid areas.The mature leaves of P.euphratica have comparatively more epidermis and cuticles,well developed palisades and more chloroplasts at different sites compared to the young leaves.Foliar morphological and anatomical variability in P.euphratica may be considered an adaptive advantage that enables leaves to develop and function in different habitats,marked by strong variations in solar radiation,air temperature,humidity and water table.     

常绿阔叶林两种树种幼苗对不同光环境的适应——关于生长特征和光合色素含量的研究

在旷地（相对光强100%）、林窗（18%～23%）、林下（3%～7%）3种自然光环境下,通过比较缙云山亚热带常绿阔叶林演替前期种四川大头茶（Gordonia acuminate）和顶级种薄果猴欢喜（Sloanea leptocarpa）的幼苗生长、生物量和光合色素含量,探讨不同生态习性亚热带常绿阔叶树种幼苗对光环境的适应及响应的异同.结果表明：1）在旷地环境,两种幼苗具有低的比茎长（SSL）、单位鲜重叶绿素（ChlM）、单位面积叶绿素（ChlA）、单位鲜重类胡萝卜素（CarM）和高的类胡萝卜素/叶绿素（Car/Chl）以适应高光环境.与四川大头茶相比,薄果猴欢喜具有高的茎生物量比（SMR）、Car/Chl和低的SSL、叶生物量比LMR（p〈0.05）;2）在林下环境,两种幼苗具有高的比叶面积（SLA）、叶面积比（LAR）、ChlM、ChlA、CarM和低的Chl a/b以适应低光环境.与四川大头茶相比,薄果猴欢喜具有更大的SLA,LAR,ChlM,ChlA,CarM和更低的Chl a/b（p〈0.05）.上述结果表明：早期种四川大头茶适应旷地光环境的能力略强于顶级种薄果猴欢喜,但适应林下的能力较差.两种幼苗对光适应能力的差异一定程度上可以解释它们在常绿阔叶林中不同的演替地位.     

蔬菜中硫氰酸化合物的测定

硫氰酸化合物广泛地存在于十字花科作物中，一些研究指出它与这些作物呈现出甲状腺素活性和对某些虫害的发生有关。本研究测定了国内常见的五种十字花科蔬菜中SCN-的含量.同时对此分析方法的适宜条件进行了模索，提供了一种较为简便快速测定SCN-的分析方法。在0.5M HNO:介质中，过量的Fe~(3+)SCN-反应显色，反应混合物的入max为460 nm，测定范围:0～2.0ug/ml(KSCN)，相关系数r=0.9994，最低检出限:04ug/ml(KSCN)     

桂花果类黄酮分离纯化工艺及其抗氧化研究

从桂花果中提取类黄酮并用分光光度法测出其含量,通过静态吸附、解吸试验,筛选出对桂花果类黄酮化合物有吸附优势的吸附剂,并检测静态吸附性能,从而达到纯化提取液之目的;最后对桂花果中类黄酮化合物体外清除羟基自由基、超氧自由基的作用进行了研究.结果表明:AB-8树脂具有较好的吸附和解吸效果,其在吸附时间6 h、解吸剂浓度80%、解吸剂体积10 mL的条件下,对桂花果类黄酮化合物的分离纯化效果最佳;桂花果中类黄酮化合物对羟基自由基、超氧自由基有一定的清除作用,并具有较强的还原能力,且类黄酮化合物的浓度在试验范围内与清除率呈正相关.