根际效应对大豆田土壤线虫群落组成及多样性的影响

根际作为重要的环境界面是植物与环境之间物质能量交换的场所,关于根际效应的研究已成为土壤生态学的新兴热点领域,然而有关大豆根际效应对土壤动物多样性影响的研究报道并不多见。在三江平原选择连续耕作15a的大豆田,对大豆根际区与非根际区土壤线虫群落结构组成进行了对比分析。结果表明:大豆根际区土壤线虫总数、辛普森多样性指数(Dom)显著高于非根际区,根际区的物种数(S)、物种丰富度指数(SR)显著低于非根际区。说明大豆根际效应增加土壤线虫的丰度,但降低了线虫群落结构的复杂性。大豆根际区植物寄生线虫(PP)、食真菌线虫(FF)和食细菌线虫(BF)数量显著高于非根际区,而PP类群的比例在根际区却显著低于非根际区。这一研究结果表明食微线虫(FF和BF)类群在大豆根际区的比例增加更显著。食真菌与食细菌线虫数量比值(F/B)指示大豆根际区细菌生物量相对高于真菌生物量。研究结果丰富了农田土壤线虫多样性的研究内容,并为我国东北大豆田线虫病害的防治及定制相应的农业管理措施提供参考。     

生活垃圾堆肥基质草坪建植体系接种草坪土壤线虫多样性特征

通过城市生活垃圾堆肥基质草坪建植体系接种草坪土壤线虫,研究了线虫数量、科属分类、营养类群等线虫多样性变化.结果表明,接种草坪土壤线虫 4 个月后,垃圾堆肥基质中共鉴定出线虫4科7属,包括植物寄生性线虫、食真菌线虫和食细菌线虫3个营养类群;垃圾堆肥基质草坪建植体系中线虫总数明显少于土壤基质.在接种草坪线虫的土壤基质草坪建植体系中,植物寄生线虫为优势营养类群,盘旋线虫属仍为优势属,相对多度达到83.3%,显著高于本底土壤45.1%.在接种草坪土壤线虫的垃圾堆肥基质草坪建植体系中,土壤本底中处于优势属的植物寄生类线虫如盘旋线虫属和螺旋线虫属基本消失了,表明垃圾堆肥基质对植物寄生类群的生长与繁殖表现出明显的抑制作用,优势属也发生了很大变化,食细菌类群的头叶属和丽突属成为优势属,相对多度分别为67.0%和14.0%.因此,从草坪土壤线虫危害角度来说,以垃圾堆肥作为草坪基质将会为草坪植物生长创造良好的基质环境.     

热带亚热带植物学报 第15卷第1-6期总目录

第1期香根草属与狼尾草属植物对土壤线虫营养类群的影响邵元虎,夏汉平,周丽霞,林永标,赵灿灿,傅声雷(1)大亚湾海域锥状斯氏藻孢囊形成与萌发的季节变化王朝晖,齐雨藻,辜小莲(9)中国主栽香蕉品种和INIBAP引进品种的SSR分析研究宁淑萍,许林兵,魏平,葛学军(16)姜花(Hedychium coro     

甘南高寒草甸土壤线虫营养功能群的地统计学分析

土壤线虫是土壤生态系统的重要指示生物。研究高寒草甸土壤线虫营养功能群空间分布格局特征,有助于揭示土壤线虫分布对高寒草甸生态因子变化的响应。2019年7月中旬,采用网格法(1.0 m×0.5 m)研究5.0 m×4.0 m尺度土壤层(0～20 cm)土壤线虫营养功能群空间特征。采用改良湿漏斗法,共获得土壤线虫1 830条,隶属于49属,土壤线虫个体平均密度以50 g干土计量为63.2条,其中,绕线属(Plectus)和拟丽突属(Acrobeloides)为优势类群。土壤线虫以食细菌线虫、植物寄生线虫为主。土壤线虫营养功能群变异系数介于64.26%～107.69%(n=38)之间,存在较强的变异性。食真菌线虫与食细菌线虫(P <0.001)、食真菌线虫与植物寄生线虫(P <0.001)间空间分布均存在显著相关性。地统计分析显示,土壤线虫营养功能群的空间相关范围存在明显差异,有效变程介于0.50～27.07 m之间,其67.26%～99.79%的变异与空间自相关过程有关。食细菌土壤线虫分布格局呈较均匀的斑块镶嵌结构,斑块较小;非食细菌土壤线虫呈斑块连接或斑块镶嵌结构,斑块较大且斑...     

宁夏枸杞根际土壤线虫群落特征

宁夏枸杞具有很高的药用价值和营养价值,在宁夏大面积种植,带来了巨大的经济效益.研究不同条件下宁夏枸杞根际土壤线虫群落特征,对防止枸杞园土壤退化具有重要意义.以宁夏枸杞之乡——中宁为研究区,系统分析了季节、树龄和土层对枸杞根际土壤线虫数量和生态指数的影响.结果表明: 夏季宁夏枸杞根际土壤线虫数量最多,小杆属和拟丽突属为优势属;春季线虫数量最少,小杆属、针属和盘旋属为优势属;从春季到秋季,线虫稀有属种类和个体密度逐渐减少.随着树龄的增加,夏季根际土壤线虫总数逐渐减少;春季和秋季枸杞根际线虫总数先增加后减少,其中9年树龄根际土壤线虫总数最多.各树龄根际均为食细菌线虫所占比例最大,食真菌线虫和捕食-杂食类线虫比例很小,树龄<3年和>9年时植物寄生线虫比例相对较大.夏季枸杞根际20～40 cm比0～20 cm土壤线虫数量增加49.4%.随着树龄的增加,枸杞根际土壤线虫多样性指数、均匀度指数和丰富度指数均呈减小-增大-减小的趋势,而优势度指数先减小后增大.土壤pH值与土壤线虫优势度指数呈显著正相关;土壤有机质和速效磷与植物寄生线虫分别呈显著正相关和负相关;土壤碱解氮与线虫总数呈显著正相关;速效钾与线虫多个生态指数均呈显著负相关.整体上,随着树龄的增加,春季和秋季土壤线虫数量先增加后减少,夏季土壤线虫数量呈逐渐减少的趋势;线虫多样性下降,土壤逐渐退化.此外,在幼林和树龄>9年后需要抑制土壤植物寄生线虫的繁殖,以减少后期因线虫引起的病害.     

土壤线虫群落对施用EM生物有机肥的响应

1997年在中国农业大学曲周试验站设置了施用EM堆肥与传统堆肥的田间试验,2004年和2005年在玉米与小麦生长期间取样分析土壤线虫的群落结构,结果表明:在玉米与小麦田总共发现49个线虫属,包括17个食细菌线虫属,5个食真菌线虫属,18个植物寄生线虫属,9个捕食-杂食线虫属。在EM堆肥处理中共发现46个线虫属,而在传统堆肥处理中共发现42个线虫属。植物寄生线虫是优势的营养类群,其次为食细菌线虫,它们的相对丰度分别是59.26%,31.55%。在玉米与小麦生长季节,线虫的Wasilewska、营养多样性、申农多样性、均匀度及植物寄生线虫成熟指数处理之间差异不显著,但是取样日期之间差异显著(P0.01)。与传统堆肥相比,多年施用EM堆肥加快了土壤有机物的转化,提高了土壤的含氮量,增加了土壤线虫总数与食细菌线虫数量。     

草莓连作土壤酚酸类物质积累对土壤线虫的影响

通过大田试验和盆栽试验相结合的方式,对不同连作年限草莓土壤酚酸类物质含量、土壤线虫数量和食细菌线虫数量以及外源酚酸类物质对土壤线虫数量和食细菌线虫数量的影响进行了研究。结果表明:随连作年限的增加,草莓连作土壤中酚酸类物质含量明显增加,土壤线虫总数和食细菌线虫总数整体呈现下降趋势,且连作5年的土壤线虫总数和食细菌线虫数量最低,酚酸类物质含量与土壤线虫总数和食细菌线虫数量呈负相关;对羟基苯甲酸和对香豆酸在浓度低于200μg·g-1时使土壤线虫总数和食细菌线虫数量增加,而高于200μg·g-1时起抑制作用;肉桂酸在浓度低于100μg·g-1时增加了土壤线虫总数和食细菌线虫数量,而高于100μg·g-1时起抑制作用;随阿魏酸浓度的增加,线虫数量变化规律不明显,当其浓度高于100μg·g-1时起抑制作用;混合酚酸随浓度增加对土壤线虫总数和食细菌线虫数量的抑制作用增强。     

悉生培养微缩体系食细菌线虫提高土壤激素含量的机制

研究土壤食细菌线虫与细菌的相互作用及其生态功能是土壤生态学的核心内容之一。食细菌线虫取食细菌可以促进土壤中氮素的矿化,提高氮素养分的供给,改善土壤的营养条件,从而促进植物的生长发育。土壤食细菌线虫促进植物根系生长的"养分作用机制"已得到确认,而"激素作用机制"还存在争议。从供试土壤中筛选获得一株高效产IAA细菌和两种不同cp值的食细菌线虫,通过设置简化的悉生培养系统,对这两种土著食细菌线虫与土著产IAA细菌之间的相互作用,及其对土壤中IAA含量变化的影响进行研究。结果表明:两种食细菌线虫的取食均能促进细菌数量和活性的增强,食细菌线虫与产IAA细菌相互作用也能显著增加土壤中IAA的含量;这些促进作用受到接种食细菌线虫的种类以及培养时间的影响:在培养第10天和第20天时,接种cp值为1的中杆属食细菌线虫显著增加了产IAA细菌的数量;在培养第10天和第30天时,相比较接种cp值为2的头叶属食细菌线虫,接种中杆属食细菌线虫显著提高了土壤中IAA的含量。     

两种盐生植物根际土壤细菌多样性和群落结构

应用高通量测序技术对西北干旱区两种盐生植物黑果枸杞和里海盐爪爪根际土壤细菌的多样性和群落结构进行研究,旨在揭示两种耐盐植物根际土壤细菌之间以及根际与非根际细菌群落结构间的差异,为深入研究盐生植物根际土壤微生物与耐盐性之间的关系提供理论基础。结果表明:黑果枸杞、里海盐爪爪根际细菌多样性丰度高于非根际土,黑果枸杞根际土壤细菌多样性丰度高于里海盐爪爪。根际和非根际土壤细菌群落的组成和丰度存在差异,从黑果枸杞和里海盐爪爪根际土壤中分别检测出细菌21门289属和22门304属,而从非根际土壤中分别检测出28门285属和24门336属;在两种盐生植物根际土壤中,变形菌门和厚壁菌门均为优势门;拟杆菌门、放线菌门、蓝细菌门及浮霉菌门在根际土壤中的丰度显著高于非根际土壤,而厚壁菌门在根际土壤中的丰度低于非根际土壤。两种植物根际土壤中的细菌优势门和优势属的数量均高于非根际土壤,在黑果枸杞和里海盐爪爪的根际土壤中的细菌优势属分别有10个和9个,而二者非根际土壤中的细菌优势属各有4个,其中假单胞菌属是根际和非根际土壤中的共有优势属。黑果枸杞和里海盐爪爪根系细菌群落组成和丰度存在差异,只有假单胞菌属和盐单胞菌属是两种植物根际土壤中的共有优势属。Unifrac分析和聚类分析表明,两种盐生植物根际土壤细菌之间的相似性大于根际和非根际细菌群落间的相似性。细菌多样性与土壤有机碳、有机质、总氮正相关,与pH、电导率负相关,电导率和pH,有机碳和总氮分别是非根际土,根际土壤细菌群落物种组成的主要影响因素。     

不同生境黑果枸杞根际与非根际土壤微生物群落多样性

研究典型生境黑果枸杞根际与非根际土壤微生物群落多样性及其与土壤理化性质间的关系,为进一步研究黑果枸杞抗逆性提供理论数据。采集新疆精河县艾比湖地区(EB)盐碱地、乌苏市(WS)路旁荒地、五家渠市(WQ)人工林带的黑果枸杞根际与非根际土壤,利用Illumina-MiSeq高通量测序技术分析细菌和真菌群落组成和多样性。结果表明:根际土壤细菌多样性高于非根际土壤(WQ除外),而根际真菌多样性低于非根际土壤。WQ非根际土壤细菌和真菌多样性均高于EB和WS;根际细菌多样性排序为EBWSWQ,根际真菌多样性排序为WSEBWQ。根际土壤优势细菌门依次是变形菌门、拟杆菌门、放线菌门、酸杆菌门,真菌优势门为子囊菌门、担子菌门。根际土壤细菌变形菌门、拟杆菌门、酸杆菌门的相对丰度高于非根际土壤,而厚壁菌在根际土壤中的丰度显著降低,真菌优势门丰度在根际土和非根际土中的变化趋势因地区而异; Haliea、Gp10、Pelagibius、Microbulbifer、假单胞菌属、Thioprofundum、Deferrisoma是根际土壤细菌优势属;多孢子菌属、支顶孢属、Corollospora、Cochlonema是根际真菌优势属。细菌、真菌优势类群(门、属)的组成以及丰富度存在地区间差异,厚壁菌门在EB地区的丰富度显著高于含盐量较低的WS、WQ;盐碱生境EB中根际土壤嗜盐细菌的丰度高于非盐碱生境(WQ、WS),如盐单胞菌属、动性球菌属、Geminicoccu、Pelagibius、Gracilimonas、Salinimicrobium等。小囊菌属是EB根际真菌的最优势属,Melanoleuca是WQ和WS的最优势属,地孔菌属、Xenobotrytis、Brachyconidiellopsis、多孢子菌属等在EB根际土壤中的丰度显著高于WQ和WS。非盐碱生境(WS和WQ)的微生物群落之间的相似性较高,并且高于与盐碱环境(EB)之间的相似性,表明土壤含盐量对微生物群落组成丰度具有重要的影响。     

辐射处理对冷季型草幼穗分化的影响

以C60Or射线对一年生黑麦草(品种:冠军)、多年生黑麦草(品种:爱神特)、早熟禾(品种:歌来德)及高羊茅(品种:知音)4个禾本科草坪草干种子进行辐照,剂量分别是15000rad(处理Ⅰ)、25000rad(处理Ⅱ)、35000rad(处理Ⅲ).播种生长后,田间取样观察;实验结果表明,所用剂量对冷季型草的幼穗分化进程影响不大,相对而言高剂量对多年生黑麦草的生殖生长有一定延长作用.     

气候条件对典型草原牧草生长发育影响浅析

采用兴安盟扎赉特旗2004年～2011年气候生态环境监测站监测的典型草原牧草生长发育及地上生物量等基本资料。典型草原主要牧草种类有贝加尔针茅、野古草、羊草等禾草,伴生中旱生杂草、灌木及半灌木组成,草丛一般高30～50 cm。本文详细分析了当地气候条件对典型草原牧草生长发育及产量的影响。结果表明,典型草原牧草的高度、盖度及地上生物量受温度和降水量影响最明显,其中降水量的影响超过温度的影响。降水量多的年份地上生物量明显增加,而干旱年份地上生物量减少,其最大值一般出现在7月份,并滞后于降水量最大值。     

Utilization of Grasses for Potential Biofuel Production and Phytoremediation of Heavy Metal Contaminated Soils

This research focuses on investigating the use of common biofuel grasses to assess their potential as agents of long-term remediation of contaminated soils using lead as a model heavy metal ion. We present evidence demonstrating that switch grass and Timothy grass may be potentially useful for long-term phytoremediation of heavy metal contaminated soils and describe novel techniques to track and remove contaminants from inception to useful product. Enzymatic digestion and thermochemical approaches are being used to convert this lignocellulosic feedstock into useful product (sugars, ethanol, biocrude oil + biochar). Preliminary studies on enzymatic hydrolysis and fast pyrolysis of the Switchgrass materials that were grown in heavy metal contaminated soil and non-contaminated soils show that the presence of lead in the Switchgrass material feedstock does not adversely affect the outcomes of the conversion processes. These results indicate that the modest levels of contaminant uptake allow these grass species to serve as phytoremediation agents as well as feedstocks for biofuel production in areas degraded by industrial pollution.     

Recent advances in genetic transformation of forage and turf grasses

Summary Forage and turf grasses are critical to sustainable agriculture and contribute extensively to the world economy. Tremendous progress has been made in genetic transformation of forage and turf grasses in the past decade. The rapid advancement of cellular and molecular biology and transgenic technology provides novel methods to accelerate and complement conventional breeding efforts. This review summarizes the latest developments in genetic transformation methods and the applications of molecular techniques for the improvement of forage and turf grasses.     

百喜草及其在南方果园生草栽培和草被体系中的应用

果园立地条件差、土壤肥力不足是影响我国果树产量和果实品质的重要因素。百喜草是优良的果园生草栽培和草被体系草种。在我国南方果产区推广应用百喜草,对于防止水土流失、改善果园生态环境、培肥果园土壤、提高果实产量和品质具有重要意义。     

北京地区野生草种资源及其开发利用

本文论述了北京市的野生草种资源及其利用现状,分析了北京市开发野生草种的前景,指出北京市在野生草种的开发利用中,应重点加强野生草种的引种驯化、野生草种的新品种选育,确定野生草种的发展方面,加强宣传,增强人们对野生草种的认识,保护性的开发利用野生草种等工作,使之成为北京市的主要产业之一.     

GROWTH OF CYMBOPOGON CITRATUS AND VETIVERIA ZIZANIOIDES ON Cu MINE TAILINGS AMENDED WITH CHICKEN MANURE AND MANURE-SOIL MIXTURES: A POT SCALE STUDY

The Rakha Cu mines are located at East Singhbhum, Jharkhand, India and their activities ceased in 2001. The tailings (residue) were permanently stored in tailings ponds that require vegetation to reduce their impact on the environment. A pot scale study was conducted to evaluate the suitability of Cymbopogon citratus (DC.) Ex Nees and Vetiveria zizanioides (L.) Nash for the reclamation of Cu tailings and to evaluate the effects of chicken manure and soil-manure mixtures on the revegetation of such tailings. Application of manure and soil-manure mixtures resulted in significant increase in pH, EC, OC, CEC and nutritional status of Cu tailings. The environmentally available and DTPA extractable Cu and Ni concentration reduced in amended tailings, while Mn and Zn content increased significantly. Plants grown on amended tailings accumulated lesser Cu and Ni but higher Mn and Zn. Plant biomass increased proportionally to manure and soil-manure mixtures application rates. Lemon grass produced more biomass than vetiver grass in either of the amended tailings. From the pot experiment, it can be suggested that application of chicken manure @ 5% (w/w) and in combination with lemon grass, could be a viable option for reclamation (phytostabilization) of toxic tailings.     

Neotropical C3/C4 grass distributions – present,past and future

Changes in C₄ grass distribution and abundance are frequently observed in Quaternary, Holocene and future environmental‐change scenarios. However, the factors driving these dynamics are not fully understood, and conflicting theories have been reported. In this paper, we present a very large dataset of modern altitudinal distribution profiles of C₃ and C₄ grasses covering the entire Neotropical Andes, which was compared with actual climate data. The results of multivariate analysis demonstrate that, in the Neotropical Andes, mean annual temperature is the main factor governing the modern altitudinal distribution of C₃ and C₄ grass species. The C₃ and C₄ grass distributions were compared with simulations based on the Lund‐Potsdam‐Jena dynamic global vegetation model (LPJ‐DGVM), which allowed the present grass distribution to be estimated. Finally, the DGVM was employed to simulate past and future scenarios, using the IPCC's climate projections for 2100 and PMIP2 models for the Holocene Optimum (HO, 6000 years bp ) and the Last Glacial Maximum (LGM, 21 000 years bp ). The results were found to be significantly different from those obtained using a simple photosynthetic model. According to LPJ forced with the PMIP2 models for the LGM, during the LGM, the C₄ grasses would not have reached higher altitudes than found in the present day.     

Endophyte-mediated disease resistance in wild populations of perennial ryegrass (Lolium perenne)

Twelve wild, endophyte-infected populations of perennial ryegrass were tested for resistance against artificial infection of Drechslera siccans and Fusarium spp. Plants with identified endophyte presence (E+), together with plants free from endophytes (E−), were inoculated with serious turf grass pathogens: D. siccans (cause of brown blight) and a mixture of Fusarium species (cause of Fusarium blight). For both diseases, the positive effect of endophyte presence on plant resistance was observed. In the case of a few ecotypes, endophyte infection increased resistance against both diseases, which is of practical importance for disease control.