克隆植物的碳素生理整合及其生态学效应

碳素整合是克隆植物生理整合过程中非常重要的一部分,是克隆植物生存、生长、繁殖的物质基础.克隆植物碳素整合的基本机制具有一定的共同性或相似性,但克隆植物的种类不同、所处生境以及发育阶段不同或所受到的干扰、胁迫的程度不同,其碳素整合的范围、强度、方向、过程等也有所差异.本文对克隆植物碳素生理整合的基本特征、生态效应以及主要的影响因素进行了详细分析,并对迄今有关克隆植物碳素整合的最新研究进展进行了系统总结.同时,对碳素整合的主要研究方法进行了评价与展望,认为在今后研究中,应加强对克隆植物碳素整合的遗传学基础的研究,同时对于碳素整合的生理学、解剖学和生态学机制的研究也亟待深入.     

克隆整合提高了入侵植物空心莲子草对北美车前的竞争力

选取北美车前Plantago virginica L.为竞争背景草,以空心莲子草Alternanthera philoxeroides（Mart.）Griseb.为研究对象,通过切断或保持其先端分株与后端分株间的匍匐茎连接,研究了克隆整合对先端分株生长以及竞争力的影响。结果显示：不管是否存在竞争,克隆整合显著提高了空心莲子草先端分株的生物量、总匍匐茎长度、叶片数目和分株数目,并降低了其对茎的生物量投资。此外,克隆整合显著提高了空心莲子草先端分株对北美车前的竞争力。种间竞争显著降低了空心莲子草的生长,但并没有显著影响其生物量分配。上述结果表明,克隆整合在一定程度上能够促进入侵克隆植物的生长和竞争力,从而可能潜在影响其入侵性。     

克隆整合在空心莲子草抗病原真菌中的作用

入侵克隆杂草——空心莲子草在其入侵地给自然环境及社会经济造成严重危害,研究发现其野外种群很少感染病害。克隆整合作用在空心莲子草的生长发育中起着重要的作用,然而克隆整合作用对其抗病性影响的研究却很少。因此,设置实验以验证克隆整合在空心莲子草的抗病原真菌中是否起重要的作用。试验结果表明,空心莲子草的抗病原真菌能力显著强于同科植物苋菜,在接种病原真菌立枯丝核菌40 h后,苋菜叶片的侵染面积达到50%以上,而空心莲子草叶片的侵染面积不到10%;且克隆整合作用促进了空心莲子草顶端分株的地上部分的生长,茎段相连处理下,顶端的茎长、茎节数、茎的生物量、叶片数量、叶片生物量都显著高于基端,而茎段剪切处理下,顶端分株的地上部分生长并不显著大于基端分株;叶片接种病原真菌立枯丝核菌后,相连的顶端分株的总酚含量显著高于切断分株的顶端分株的含量。且二次接种病原菌后,相连分株的病原真菌侵染叶片面积不到0.1 cm~2,显著小于剪切分株的叶片侵染面积(0.8 cm~2)。结果表明,克隆整合作用不仅促进了空心莲子草相连分株的地上部分的生长,也提高了其抗病原真菌的能力。     

胁迫生境深色有隔内生真菌生态分布与功能研究进展

深色有隔内生真菌(dark septate endophytes,DSE)是一类定殖于植物根内的小型真菌,广泛存在各种生境中,其在胁迫生境中的生态分布、生态功能与作用机理是近年来的研究热点.对DSE的生态分布、胁迫生境DSE的生态功能和DSE真菌增强植物抗逆性的作用机理等方面进行综述.研究进展表明,从平原低地到热带、温带、冻原及南北极地区,野生植物根部普遍定殖着DSE真菌,尤其在干旱、高温、寒冷、盐害、重金属污染和养分贫瘠等胁迫生境中,DSE真菌的分布更为普遍.环境胁迫条件下,植物根部共生DSE真菌能够改善植物矿质营养和光合生理、调节植物内源激素平衡、增强植物抗氧化生理,从而促进宿主植物生长、增强植物抗逆能力,以及改变植物对重金属的吸收累积,在植物耐受和适应胁迫环境中起着重要的调节作用.但这些研究主要从生态现象进行了研究,目前对DSE增强宿主植物抗逆性的作用机理仍很缺乏、不够系统深入.未来应建立DSE真菌种质资源库,加强DSE真菌的应用技术研究;结合现代生物技术和方法,系统深入研究DSE真菌提高植物抗逆性的生理和分子机制,为利用DSE真菌增强植物适应环境胁迫提供理论依据.(表1参92)     

VA菌根在柑桔上的应用及其前景

由于菌根在农业、林业生产中的重要性,对菌根的研究,尤其是对VA菌根的研究已引起人们广泛的重视.本文对VA菌根的研究及利用现状,尤其是VA菌根与植物营养,VA茵根与植物的抗性生理以及VA菌根、根瘤菌与植物三联体的效应等方面的动态作一综述,并对柑桔菌根今后的研究提出几点建议,其中包括菌根资源的调查、菌根资源圃的建立、柑桔菌根与环境、菌根与柑桔的抗性生理等。     

外源污染物对蚯蚓毒理作用研究进展

以蚯蚓为模式生物,研究环境污染物的生物效应及其对土壤生态系统的影响,已成为国内外的研究热点.蚯蚓受到污染胁迫时,在分子、细胞和生理水平上都会发生明显的变化,进而影响其存活、生长和繁殖能力,最终引起种群及群落的变化.在总结国内外相关研究基础上,从微观水平、个体水平及生态水平3个方面综述和分析了重金属、农药等外源污染物对蚯蚓毒理作用的研究进展,并对未来的研究方向进行了展望.     

模拟采食下克隆整合对虉草生长及生理特征的影响

为了解克隆整合对克隆植物适应均质性采食环境胁迫的作用,以江西省鄱阳湖-乐安河段河岸带优势根状茎克隆物种虉草(Phalaris arundinacea)为对象,研究均质性采食条件下虉草的生理生态响应以及克隆整合在虉草应对模拟采食两月后发挥的作用.模拟采食(去叶)强度设置4组水平:不去叶(CK对照组)、去叶25%、去叶50%和去叶75%;克隆整合采用2种方式:茎切断和连接.结果显示,无论是否进行断茎处理,模拟采食均显著(P5%)降低虉草的叶片数、地上枝总长度、分株数和生物量,去叶处理下断茎的虉草分株相对茎连接分株具有更强生长优势.断茎和去叶处理对虉草叶绿素含量无显著影响,断茎的虉草分株在25%、50%去叶水平下叶绿素a(Chl a)、叶绿素b(Chl b)和总叶绿素(Chlt)含量均高于茎连接的分株,所有去叶处理强度下断茎的虉草分株各叶绿素指标均高于对照组.去叶显著影响了虉草分株各光合指标,断茎分株在50%、75%去叶水平上的净光合速率(Pn)、气孔导度(Gs)、蒸腾速率(Tr)、胞间CO2浓度(Ci)等指标均高于茎连接分株,25%去叶处理组则相反;去叶处理的虉草分株的Pn、Tr、Ci均低于对照组.因此,采食引起虉草分株光合速率下降,使营养物质积累不足,导致生长状态下降;虉草能够在一定程度上适应均质性采食处理带来的压力,但是克隆整合不能显著改善均质性采食条件下虉草的生长.     

六溴环十二烷（HBCDs）异构体及对映体的植物富集、传输、修复及毒性研究进展

六溴环十二烷（hexabromocyclododecanes,HBCDs）是一种典型的疏水性脂肪族溴代阻燃剂,2013年被列入《斯德哥尔摩公约》受控名单中. HBCDs具有手性中心,多个对映异构体,不同的立体构型在环境中会发生选择性富集分布,降解转化和生物毒性等行为.植物是生态系统能量的生产者,HBCDs可通过植物吸收改变植物生理,影响其在食物链的传递乃至整个生态系统,对环境和人体健康存在潜在危害.本文对HBCDs异构体和对映体的植物提取分析方法、植物富集和传输、污染土壤的植物修复以及植物毒性效应的最新研究进行梳理.液相色谱质谱联用技术可有效检测植物中的HBCDs异构体和对映体,对映体水平的检测将成为未来HBCDs立体构型分析的发展方向. HBCDs已在各类植物中被陆续检出,多数研究中α-HBCD是主要的异构体.目前在HBCDs对映体水平上的研究还非常有限,其在植物体内的传输尚无统一规律.植物种植可有效清除土壤中的HBCDs,展现出生物修复应用前景.HBCDs会引起植物生长发育迟缓、氧化胁迫和基因损伤等效应,不同构型的HBCDs表现出特异的选择性毒性行为.鉴于目前关于HBCDs的植物研...     

基于数据库的植物功能性状研究现状文献计量学分析

植物功能性状数据库是功能生态学研究的重要工具.了解基于植物功能性状数据库的植物功能性状研究现状,对探讨功能多样性和生物多样性具有重要的指导意义.介绍植物功能性状数据库的类型、影响力的评价方法和使用方法,并整理了17个植物功能性状库(附表).同时,通过Web of Science检索了2008-2018年间基于植物功能性状数据库开展植物功能性状研究的论文,从刊文数量、期刊分布、研究机构、主要作者、研究热点等方面进行分析.结果表明:基于数据库开展植物功能性状研究的文章数量和被引次数呈快速增长的趋势.当前此方向的研究主要以少数学者、机构为核心,大量论文发表在少数期刊上.研究热点主要体现在群落生态学、气候变化和性状进化、恢复和生存策略等方面.未来应加强研究者、研究机构之间的合作,数据共享,建立全球型的数据完善的植物功能性状数据库,同时加强数据标准化处理,解决地下性状和生理性状等难以获取及量化的问题,完善化石记录的植物性状和植物不同生长阶段的植物功能性状数据.(图5表4参60附表1)     

农药和化肥对无尾两栖类蝌蚪的毒性效应研究进展

以两栖动物研究环境污染物的毒性效应进而监测环境的变化,已成为国内外的研究热点.两栖类的胚胎发育和变态过程对水的依赖性极强,而且鳃和皮肤有很强的渗透性,当其受到污染胁迫时,在细胞、组织及生理生化水平上都会发生显著变化,进而会影响其存活和生长发育.在总结国内外相关研究基础上,综述和分析了农药、化肥(氮肥)对无尾两栖类蝌蚪的行为表现、生长发育、组织结构和生理生化变化等方面的毒性效应,以期为农药、化肥的水环境监测及合理使用提供全面的科学依据.     

Optimal biomass allocation in heterogeneous environments in a clonal plant—Spatial division of labor

When interconnected ramets of clonal plants are growing in heterogeneous environments, ramets may specialize to uptake locally abundant resources rather than scarce resources. This biomass allocation pattern may result in more efficient sharing of resources through physiological integration and an overall benefit to the plants (spatial division of labor; DoL).     

Effects of clonal integration on the growth and physiology of Phalaris arundinacea under simulated herbivory北大核心CSCD

In order to investigate the effects of clonal integration on the adaptation of clonal plants to the environmental stress of homogeneous herbivory, we conducted a greenhouse experiment to investigate the ecophysiological response characteristics of Phalaris arundinacea collected from the riparian zone of the Poyang Lake wetland and Le'an River in Jiangxi Province and the effect of clonal integration on this dominant plant under two-months of simulated cyclical homogenous herbivory. Simulated herbivory strength was set at four different levels: no leaf removal (control) and 25%, 50%, and 75% leaf removal. We implemented two methods of clonal integration including no integration, in which the rhizome connection was severed, and integration, in which the rhizome connection was intact. We found that simulated herbivory significantly decreased the number of leaves, total shoot length, number of ramets, and biomass of P. arundinacea (P < 5%), regardless of whether the rhizomes were intact or severed. Ramets with severed rhizome connections (RRC) generally had higher growth indices than those with intact rhizome connections (RIC). Severing rhizomes did not significantly affect the chlorophyll content of P. arundinacea, while RRC under simulated herbivory intensities of 25% and 50% leaf removal had higher chlorophyll a (Chl a), chlorophyll b (Chl b), and total chlorophyll (Chlt) contents than RIC did, and simulated herbivory increased the chlorophyll contents of all ramets. RRC net photosynthesis rate (Pn), stomatal conductance (Gs), intercellular CO2 concentration (Ci), and transpiration rate (Tr) were all higher in RRC than they were in RIC under simulated herbivory intensities of 50% and 75% leaf removal; however, the opposite relationship was observed under a simulated herbivory intensity of 25% leaf removal. Further, simulated herbivory limited the photosynthetic index of P. arundinacea. These effects resulted in an inadequate accumulation of nutrients in the plant. Phalaris arundinacea can adapt to simulated herbivory treatments in terms of growth, but clonal integration cannot improve the growth of P. arundinacea under a homogeneous herbivory treatment. © 2018 Science Press. All rights reserved.     

Large scale parameter study of an individual-based model of clonal plant with volunteer computing

Understanding clonal strategies (i.e. the ability of plants to reproduce vegetatively) is particularly important to explain species persistence. A clonal individual may be considered as a network of interconnected ramets that colonizes space. Resources in this network can be shared and/or stored. We developed an individual-based model (IBM) to simulate the growth of an individual clonal plant. Typically a realistic IBM requires a large set of parameters to adequately represent the complexity of the clonal plant growth. Simulations in the literature are often limited to small subsets of the parameter space and are guided by the a priori knowledge and with heuristic aims of the researcher. The aim of this paper was to demonstrate the benefit of volunteer computing in computational ecology to systematically browse the parameter space and analyze the simulation results in order to draw rigorous conclusions. To be specific, we simulated clonal plant growth using nine growth rules related to the metabolic process, plant architecture, resource sharing and storage and nineteen input parameters. We chose 2-4 values per input parameter which corresponded to 20 millions of combinations tested through volunteer computing. We used three criteria to evaluate plant performance: plant total resource, ramet production and maximum length of one branch. The 1% top-performing plants were sorted according to these criteria. Plant total resource and ramet production were correlated while considering the top-performing plants. The maximum length of one branch was independent from the other two performance traits. We detected two processes promoting at least one of the plant performance traits: (i) a relatively high metabolic gain (high photosynthetic activity and low production cost for new growth units), a low resource storage and long integration distance for resource sharing; (ii) short spacer lengths and the predominance of elongation of existing branches over branching. Interactive effects between parameter values were demonstrated for more than half of the input parameters. Best performance was reached for plants with slightly different combinations of values for these parameters (i.e. different strategies) rather than a single one (i.e. unique strategy). This modeling approach with volunteer computing enabled us to proceed to large-scale virtual experiments which provided a new quality of insight into ecological processes linked with clonal plant growth.     

The use of nondestructive methods to assess a physiological status and conservation perspectives of <Emphasis Type="Italic">Eryngium maritimum</Emphasis> L.

Eryngium maritimum is a perennial species growing exclusively in a coastal littoral zone both on sand dunes and shingle beach and indicated as declining in Northern Europe. The objective of the present study was to prove the use of nondestructive physiological measurement methods to access physiological status of endangered plants, using E. maritimum as a model species. Plants from two Latvian sites were studied in comparison with other populations in Northern Europe (Estonia, Lithuania, Poland, United Kingdom) to find out if local differences in environmental factors affect vitality of E. maritimum individuals. Noninvasive chlorophyll analysis and chlorophyll a fluorescence measurements were used as indicators of plant physiological status through characterization of various aspects of photochemistry of photosystem II activity. Dynamics and morphology of individuals were investigated for evaluation of clonal growth potential of E. maritimum in natural conditions. Highly fluctuating trend of dynamics of individuals (within 40 groups at two Latvian sites) was established for E. maritimum in natural conditions over a five-year period. Disturbance of individuals lead to formation of new shoots from nodal root meristems. An exponential regression between fluorescence parameters F_V/F_M and Performance Index and summary monthly precipitation was found indicating that E. maritimum plants had significant tolerance to water shortage together with susceptibility to increased precipitation. Negative correlation between leaf chlorophyll content and more northern localization of individuals was found (r = 0.95 and r = 0.94, for generative and vegetative shoots, respectively). Northern populations of E. maritimum are endangered by high precipitation in conditions of low air temperature, leading to decrease of photosynthetic productivity and overall physiological status. High developmental plasticity at the root level leads to clonal growth and an efficient survival and relatively long life span of E. maritimum individuals. Chlorophyll a fluorescence is a useful method to search for the effect of suboptimal conditions on physiological status of endangered plant species without elimination and disturbance of individuals.     

Influences of season and water depth on the clonal biology of the seagrassThalassia testudinum

Ramet density, leaf relative growth rates, leaf chlorophyll levels, and proximate constituent levels were determined on three dates in 1988 at three water depths for aThalassia testudinum Banks ex Konig meadow in lower Tampa Bay, Florida, USA. Density varied seasonally in patterns unique to each depth. Leaf relative growth rates indicated a unimodal, rather than bimodal, growth pattern at this site. Leaf chlorophyll levels reflected both depth-related and seasonal influences, with levels at all depths increasing in times of high light attenuation. Based on results from leaf relative growth rates and proximate constituent levels, the degree of ramet interdependence appears to vary with sampling date and water depth. The degree of ramet interdependence appears to be maximal in times of genet expansion (June and August) and minimal in times of energy storage (November). Interdependence of ramets varies spatially as well; ramets are maximally integrated in shallow regions (on those dates when genet proliferation occurs), and minimally integrated at deep edges. Depth-related differences in ramet integration are probably due to the spatial heterogeneity of the primary resource limitation varying with water depth, and to depth-related differences in ramet population dynamics. Patterns of ramet physiological integration inT. testudinum are similar to the patterns reported for terrestrial clonal plants.     

外来入侵植物在中国的分布及入侵能力研究进展

以近十几年来备受关注的外来植物入侵为背景,综述关于入侵植物在我国分布和入侵能力及其相关因素的研究进展,并探讨了未来研究需要加强的几个方面。不同起源地的入侵植物在我国分布区域不一样,在控制了起源地的作用后,入侵植物主要分布在经济较发达、人为活动较多的省份或地区（大尺度）,以及干扰较严重的生境（小尺度）。入侵能力强的多年生植物常有强大的无性繁殖能力、高光合速率和资源利用效率、强化感作用、以及适应异质生境的能力;起源于美洲的入侵能力强的1年生植物常能产生大量的易传播的种子、可自交亲和、强化感作用等;起源于欧亚大陆的入侵能力强的1年生植物常与作物非常相似,在农田中危害严重。未来需要研究干扰促进入侵的机制、化感作用与野外实际情况相结合研究、化感物质通过改变土壤微生态环境间接促进入侵的机制研究、1年生和多年生外来植物的入侵能力与其物种特性之间的关系、以及加强对弱入侵性外来植物的预警研究。这些研究不仅能使我们深入理解外来植物发生入侵和危害的规律,也可为人侵植物的防控和管理提供科学依据。     

Variation in responses of late-seral herbs to disturbance and environmental stress

Clonal herbs that attain maximum development in late-seral forest are often assumed to have similar responses to disturbance and to be functionally equivalent. However, little is known about the demographic or physiological responses of these plants to disturbance or to the altered conditions of the post-disturbance environment. Following harvest of a mature coniferous forest, we compared abundance, demographic changes, and physiological acclimation of three clonal herbs (Asarum caudatum, Clintonia uniflora, and Pyrola picta) that differ in belowground morphology and leaf longevity. We measured ramet density, leaf area, and demographic variables (survival, clonal growth, flowering, and seedling establishment) before and for two years after harvest, and in adjacent undisturbed forest. Acclimation to increased solar radiation was assessed two years after harvest by measuring leaf mass per unit area (LMA) and chlorophyll a:b ratios of leaves produced in the current year. Although initial declines in abundance were similar, demographic responses indicate that patterns of recovery varied greatly among species. Two years after logging, ramet survival and clonal growth (production of new ramets) of Clintonia were greater in the harvest area than in the forest. Asarum had lower survival in the harvest area, but greater clonal growth, and Pyrola showed no difference in either survival or growth between environments. Only Asarum produced seedlings, although their survival was low in the harvest area. All species had higher LMA in the harvest area, but only Clintonia (with annual leaves) had a higher chlorophyll a:b ratio, suggesting the greatest potential for acclimation to increased light. Our results demonstrate that forest herbs with greater rhizome plasticity and shorter leaf duration have greater potential to acclimate after disturbance than those with rigid architectures and persistent leaves. Thus, species with comparable successional roles can vary substantially in their demographic and physiological responses to disturbance, with potential consequences for long-term recovery.     

多环芳烃污染土壤毒性评价指标的研究进展

土壤微生物、植物和动物的生理学和遗传学指标被广泛用于评价土壤中多环芳烃(Polycyclic Aromatic Hydrocarbons,PAHs)污染程度、毒性以及修复效果等,对指标本身的研究也在不断取得新认识和新进展.首先,许多研究对不同的指标进行比较,以检验它们在灵敏度上的差别;其次对指标的选择也越来越突出对PAHs污染的预警能力,因而普遍采用亚致死效应指标,且对指标的研究不断向基因、分子水平深入,力求通过早期的响应特征对PAHs污染程度做出及时判断;再次,PAHs污染土壤评价指标正不断朝着更加宏观和更加微观两个方向扩展,目前的指标体系已经覆盖了分子、细胞、个体、群落和生态系统等不同层次.论文依据PAHs毒性作用机理,从生理生化和遗传学角度综述了国内外评价PAHs污染土壤毒性时较为常用的生物指标及其研究进展,为国内进行相关研究工作提供参考.