非灭菌条件下丛枝菌根对猪血木幼苗生长的影响

以猪血木幼苗为研究对象,在非灭菌条件下进行幼苗接种丛枝菌根的盆栽试验.通过测定幼苗株高、叶片光合色素含量和叶片数生长动态.结合动态生命表和株高增长动态分析方法.探讨了非灭菌条件下丛枝菌根对濒危植物猪血木幼苗生长的影响.结果表明,与对照组相比,接种丛枝菌根提高了叶片光合色素的含量.显著提高了幼苗的存活率,促进幼苗的株高和叶片生长;动态生命表分析表明.接种丛枝菌根的幼苗在生长初期的48周中无明显的危险死亡期:对照组幼苗存活率曲线为Deevey-Ⅲ型,幼苗在初期表现出较高的死亡率.故接种丛枝菌根能促进猪血木幼苗的生长,增强幼苗对环境的适应性,提高幼苗的存活率.研究结果为该濒危物种的有效保护和种群恢复提供了理论依据.     

Biochemical approaches to the study of plant-fungal interactions in arbuscular mycorrhiza

This communication compares some biochemical methods for quantifying colonization by arbuscular mycorrhizal (AM) fungi. The degree of mycorrhizal colonization can conveniently be measured by determining fungal specific sterols. AM-colonized plants show a specific synthesis of 24-methylene cholesterol and an enhanced level of campesterol (=24-methyl cholesterol). A gene probe for nitrate reductase, the key enzyme for nitrogen assimilation, has been developed, which allows the monitoring of the distribution of this enzyme in fungi. Among the phytohormones tested, only abscisic acid (ABA) is found at a considerably higher level in AM-colonized plants than in controls. The concentration of ABA is about twenty times higher in spores and hyphae of the AM fungusGlomus than in maize roots. Other phytohormones (auxins, cytokinins) do not show such alterations after mycorrhizal colonization. The roots of gramineous plants become yellow as a result of mycorrhizal colonization. The yellow pigment(s) formed is (are) deposited in larger quantities in the vacuole(s) of the root parenchyma and endodermis cells during the development of the gramineous plants. A substance isolated from such roots has now been identified as a C-14 carotenoid with two carboxylic groups, and named mycorradicin.     

AM真菌对盐碱胁迫下杜梨幼苗生长与生理代谢的影响

【目的】探究接种丛枝菌根真菌(arbuscular mycorrhizal fungi, AMF)对盐碱胁迫下杜梨幼苗生长与生理代谢及耐盐碱能力的影响,为杜梨菌根苗在盐碱地上植被构建中的应用提供理论依据。【方法】采用双因素试验设计,以1年生杜梨实生苗为材料,将幼苗分为AMF(摩西管柄囊霉,Funneliformis mosseae)接种和未接种两组,以Na₂CO₃同时进行盐碱处理(浓度梯度为0、100、200和300 mmol/L),并测定其生长与生理性状。【结果】接种AMF提高了盐碱胁迫下杜梨幼苗的株高生长量(△H)以及生物量积累,与未接种幼苗相比,接种组幼苗的△H和生物量在盐碱胁迫下降低的幅度显著减小。丛枝菌根在一定程度上降低了Na⁺在杜梨根和叶的积累,在3个Na₂CO₃浓度处理下,接种组幼苗根中Na⁺的含量分别比未接种组低10.8%、21.6%和19.4%,从而提高了接种组幼苗根和叶中K⁺/Na⁺、Ca²⁺/Na⁺、Mg²⁺/Na⁺的比值以维持较好的离子平衡状态。接种AMF可以提高盐碱胁迫下杜梨幼苗叶的叶绿素含量,降低脯氨酸和丙二醛在叶中的积累,表明接种AMF可以减轻盐碱胁迫对杜梨造成的离子毒害与过氧化伤害。【结论】AMF直接影响盐碱胁迫下杜梨幼苗生理代谢,提高其光合色素含量,维持其体内离子相对平衡,减少活性氧伤害,从而提高了杜梨幼苗的耐盐碱能力,促进其在盐碱胁迫下的生长。     

不同基质条件下丛枝菌根真菌对桑树生长的影响

【目的】研究不同基质条件下桑树接种丛枝菌根(AM)真菌后的生长情况,以筛选适合桑树育苗的基质和AM真菌种类,为桑树的生态和经济产业发展提供技术支撑。【方法】采用G_a(聚丛球囊霉Glomus aggregatum)、G_c(苏格兰球囊霉Glomus caledonium)、G_i(根内球囊霉 Glomus intraradices)、G_v(地表球囊霉 Glomus versiforme)、BGCH(透光球囊霉Glomus diaphanum BGC HEB07A)、BGCX(幼套球囊霉Glomus etunicatum BGC XJ03C)6种丛枝菌根真菌(arbuscular mycorrhiza,AM真菌),设置P1(牛粪、菇渣、珍珠岩、黄心土体积比6.0:3.0:0.5:0.5)、P2(牛粪、菇渣、珍珠岩、黄心土体积比6:2:1:1)、P3(黄心土)3种基质配比,研究不同基质条件下接种AM真菌对桑树生长情况的影响。【结果】G_c、BGCX和BGCH 3种AM真菌对桑树根系的侵染率最高,且基质P1中的侵染率显著高于P2和P3; 接种G_c和BGCH桑树种子的发芽率最高,且在基质P1中表现更好; 接种AM真菌桑树的株高、地径、根系表面积、根系总长度、根尖数量和根系生物量均显著高于未接种的桑树,以G_c、G_v和BGCH 3种效果最好,且在基质P1中表现更好; 接种AM真菌桑树的净光合速率、水分利用效率、PSⅡ(光系统Ⅱ)最大光化学效率、PSⅡ天线转化效率、实际原初光化学效率、光合电子传递速率等参数值均显著高于未接菌种的桑树,总体上以G_c、G_v和BGCH 3种效果最好,且在基质P1中表现更好。【结论】AM真菌促进了桑树的生长,以G_c和BGCH 两种最优,且以基质P1最佳。     

丛枝菌根真菌的生态分布

介绍了丛枝菌根真菌的生态分布研究进展情况,并从生物因素和非生物因素两个方面对丛枝菌根真菌生态分布的影响进行了探讨.     

Pb胁迫下接种丛枝菌根真菌对茶树解毒能力的影响

采用盆栽试验研究了接种丛枝菌根真菌(Arbuscular mycorrhizal fungi,AMF)对铅(Pb)胁迫下茶树解除Pb毒性能力的影响,分别用醋酸墨水染色法、考马斯亮蓝法、电感耦合等离子体(ICP-MS)、紫外分光光度法等方法研究了接种AMF后茶树根系菌丝的侵染率,土壤中球囊霉素(Glomalin-related soil protein,GRSP)含量,茶树根系、叶片、土壤中及GRSP中Pb含量及叶片的抗氧化酶活性.结果表明,接种AMF后,茶树根系菌丝侵染率为60.13%,茶树的生物量、百芽重和显著增加,并极显著地提高土壤中总GRSP含量,由于GRSP对Pb的大量螯合作用,使得土壤中Pb的生物有效性大大降低,加之茶树根系、叶片中对Pb的总吸收量减少,且根系Pb含量增加,因此,叶片中Pb含量显著下降,抗氧化酶活性也相应地下降.     

Different responses of arbuscular mycorrhizal fungal community to day-time and night-time warming in a semiarid steppe

Arbuscular mycorrhizal （AM） fungi form mutualistic symbioses with most plant species and play important roles in ecosystems. Knowledge of the response of AM fungi to temperature change will improve our under- standing of the function of AM fungal community under global climate change scenarios in ecosystems. The effects of constant warming on AM fungal communities have been investigated previously, but responses to asymmetrical warming over 24-h periods have never been documented in natural ecosystems. In this study, we examined AM fungal communities in a full factorial design including day-time and night-time warming in a semiarid steppe in northern China. Day-time and 24-h warming, but not night-time warming, significantly increased AM fungal spore density. In contrast, none of the three warming regimes had a sig- nificant effect on AM fungal extra radical hyphal density. A total of 161 operational taxonomic units （OTUs） of AM fungi were recovered by 454 pyrosequencing of 18S rDNA. Day-time, night-time, and 24-h warming all significantly increased AM fungal OTU richness. Some AM fungal OTUs showed a significant bias toward day-time, night-time or 24-h warming. The AM fungal community composition was significantly affected by night-time warming, but not by day-time and 24-h warming. Our finding highlighted dif- ferent responses of AM fungal spore density and community composition to asymmetrical warming. This study might improve our understanding of ecosystem functioning of AM fungal community under global climate change scenarios in a semiarid steppe ecosystem.     

丛枝菌根对尾矿环境的生态修复作用

采矿业在促进国民经济发展的同时,也带来严重的环境问题。残留的大量尾矿不仅造成土地资源的浪费,还严重污染了生态环境。尾矿的物理结构很差,极端贫瘠、重金属含量高、具有极端pH值,致使植被难以覆盖,生态修复困难。丛枝菌根真菌在矿区生态恢复中发挥了较好的效应,能够促进宿主植物对矿质元素的吸收,提高植物抗逆性,尤其是对重金属的抗性。因此,丛枝菌根真菌对于尾矿库的生态修复具有很大的应用潜力。     

应用菌根技术进行西北地区土地复垦初探

煤炭生产及消费造成地表耕地及植被破坏和污染环境等问题对西北地区的可持续发展造成危害 ,本文以利用煤矸石、粉煤灰培植植物试验实例初步证明菌根技术对煤矿区土地复垦具有积极作用 ,进而就西北地区应用菌根技术进行土地复垦给出初步的技术途径     

Mycorrhizas in ecosystems

Summary The results of analyses of the distribution, structure and function of ericoid, ecto and vesicular-arbuscular mycorrhizas are used to challenge the conventional view, which was based largely upon studies of isolated plants and excised plant roots under controlled conditions, that the symbiosis is primarily involved in the capture of phosphate ions. In nature, each mycorrhizal type is associated with an ecosystem and soil environment with distinctive characteristics in which selection has favoured the development of a particular range of attributes. These attributes are evaluated and their importance for the individual plant and for the ecosystems in which they occur is assessed. It is concluded that knowledge of the full range of functions of each mycorrhizal type is essential for an understanding of the distribution and dynamics of the ecosystem in which it predominates.