由治汾美化工程看生态河堤建设

生态河堤也叫“多种生物共生、繁殖治理法”，它以保护、创造生物良好的生态环境和自然景观为前提。生态河堤一般分为自然原型护岸、自然型护岸和多自然型护岸三种，其特点是建立多生物共生的生态系统、滞洪补枯、增强水体自净作用、增强城市自然景观。国内外的生态河堤建设实践给太原市治汾美化工程以有益的启示，应结合汾河的水文、地质与植物特征进行研究，制定生态河堤规划，逐步实施。     

共生丛植菌根减轻番茄黄化卷叶撒丁岛病毒症状和降低病毒浓度

正共生丛枝菌根(arbuscular mycorrhizal,AM)对生物和非生物胁迫经常表现出较高的耐受力,被认为是一种能够改善植物健康和提高植物产量的天然工具,然而AM与病毒感染的关系一直很少被人们关注和深入研究。意大利国家研究委员会的G.Maffei团队通过一系列试验,探索了共生菌根(funneliformis mosseae)与番茄黄化卷叶撒丁岛病毒(Tomato yellow leaf curl Sardinia virus,TYLCSV)的相互作用,为防治在地中海地区肆虐的番茄黄化卷叶病毒病提供了新途径,具有重要的理论和实际意义,其相关研究结果于2013年9月发表在《Mycorrhiza》上。许多研究表明,AM除了可以改善无机营养,还能够提高共生植物耐受不良生物和非生物环境的耐受力,从而增进植物健康。AM还可以影响植物与病原物的互作,目前已在很多土传病害病原菌上观察到了有益效果。但是关于植物病毒与共生菌根互作却鲜有报道。     

藻菌共生系统处理畜禽沼液的机制及影响因素研究进展

畜禽沼液不仅含有高浓度氨氮、总磷、难降解有机物以及重金属和抗生素等风险因子,同时也存在大量有效氮、磷、钾等营养成分,未经过适当处理的沼液直接排放极容易造成水体的富营养化、土壤酸化和污染物累积等生态环境问题,加上沼液极具资源化潜力,因此对其进行有效的处理与资源再利用对于促进可持续发展具有重要意义。微藻细菌共生系统(藻菌共生系统)作为一种新兴的沼液处理方式,得到了广泛关注与研究。相较于传统的沼液处理方法,藻菌共生系统具有低成本、高效率、环境友好等优点,其不仅可高效去除沼液中的氮、磷、重金属、抗生素等物质,而且能同步利用CO₂进行光合作用,产生具有生物燃料潜质的微藻生物质,应用前景广阔。该文分析总结了藻菌共生系统的共生机制,概括了其类型,系统解析了其去除沼液污染物的机理,并重点阐述了藻菌共生系统的影响因素,最后讨论和展望了该系统所面临的挑战与未来的发展方向,以期为基于藻菌共生系统的沼液规模化处理及利用提供理论指导。     

共生固氮在农牧业上的作用及影响因素研究进展

共生固N是生物固N的主体部分,具有固N效率高、应用范围广等特点。叙述了主要豆科作物年固N量及固N量占豆科作物本身所吸收N的比例,阐述了豆科作物在与非豆科作物间套轮作中固定N素的转移及对非豆科作物的影响,并介绍了影响豆科作物-根瘤菌共生体共生固N效率的主要因素。开展豆科作物-根瘤菌共生体系方面的研究对农业可持续发展具有重要意义。     

莱阳农学院菌根生物技术研究所

自然界中,几乎所有的生物都不是独立生活的而是普遍存在着广义的共生关系。例如．我们把植物根系与一类真菌形成的互惠共生体称做菌根。其中，丛枝菌根（AM）和外生菌根分布最广、意义最大。     

“稻鱼共生系统”全球重要农业文化遗产价值研究

浙江青田县的“稻鱼共生系统”作为全球首批重要农业文化遗产,不仅具有提高农业生产收入,降低生产成本,产生相关经济效益等经济价值;同时,作为一种复合农业生态系统,还具有突出的生态价值,如维持农田生态平衡、保护农田生态环境、保护生物多样性等。另外,“稻鱼共生系统”还具有社会价值、文化价值、科研价值和示范价值。这些价值的研究对农业文化遗产的保护和合理开发利用具有重要意义。     

土壤中铜、铅、锌相对浓度比稳定性的研究

铜、铅、锌均与硫元素有较强的亲和力,从而使它们具有相似的地球化学性质,并在环境自然体中紧密共生.人们已经认识了铜和锌是人体必需的微量元素,而铅是有害的元素,它们的环境与生物地球化学行为,直接影响到人体的健康.因此,表生环境中的铜、铅、锌始终是研究的热点.     

转Bt基因作物对丛枝菌根真菌的影响研究进展

在过去的十年里，世界范围内转基因作物尤其是抗虫性转Bt基因作物的品种和种植面积迅速增加。同时，转Bt基因作物的环境安全性评价问题成为人们关注和研究的热点。丛枝菌根真菌（AMF）是生态系统中普遍存在的土壤微生物，能与绝大多数植物种类形成共生关系，在农业生态系统中起重要作用。转Bt基因作物环境释放后，其与AMF问的共生关系是否受所转入Bt基因的影响，以及影响机制需要及时研究。为此，综述了转Bt基因作物与AMF共生特征方面的研究进展，并根据Bt毒素发生的空间和时间规律提出了危害机制以及转Bt基因植物的规模化种植将降低农田系统中的AMF的生物多样性的观点。     

禾本科植物联合固氮的研究现状及应用前景

氮是限制农业生产的最重要因素之一。随着人工固氮技术的发展,氮肥的施用在提高作物产量、解决人类温饱问题的同时,导致了土壤板结、酸化、氮素流失及温室气体排放(N2O)等环境问题。与人工合成氨相比,生物固氮是一种绿色经济的固氮方式,其包括共生固氮和非共生(自生固氮及联合固氮)固氮,且每年固定的氮可占总固定量的50%以上。与共生固氮相比,非共生固氮存在范围广,如甘蔗、水稻、玉米和小麦等禾本科作物均能进行非共生固氮(联合固氮)。本文主要从禾本科植物的联合固氮菌种类及其作用机理、固氮活性及调控方式以及联合固氮菌的资源及应用3个方面进行综述,发现相比较共生固氮而言,联合固氮菌易受到土著微生物、氮素水平等环境因素影响,其研究难度更大,需要筛选纯化更多的联合固氮菌,为其固氮机制研究提供良好材料;氮、磷、钼、铁等肥料的适量添加可有效促进固氮菌的固氮效率;固氮菌不仅可以提高土壤固氮量,而且有利于植物根系激素调节,从而增加植物抗病抗逆能力,促进植物更健康的生长。本文最后对禾本科植物联合固氮的农艺管理措施及固氮菌剂的实际应用方面做了展望,以期为提高禾本科植物联合固氮效率及推动生物固氮菌在农业生产中的应用提供理论依据。     

昆虫病原线虫共生细菌对南方根结线虫卵孵化的影响

为探讨不同种(品系)昆虫病原线虫共生细菌的不同稀释倍数对南方根结线虫Meloidogyne incognita卵孵化的影响,采用培养皿法进行室内生测,定期调查根结线虫卵孵化情况。结果表明,4种(品系)昆虫病原线虫(斯氏属两个种和嗜菌异小杆两个品系)共生细菌的10×稀释液,6 d时Hb-NJ共生菌使M.incognita的卵孵化率最低,为8.6%,以TSY培养液为对照,其孵化率为29.1%,Hb-NJ共生菌对M.incognita卵孵化的抑制作用最强,相对抑制率为70.6%,其它3种昆虫病原线虫Hb-IGA、Sc-All和Sf-IGA共生细菌的孵化率为分别为24%、22.6%和25.2%,其相对抑制率是17.2%、22.3%和13.4%;8 d时线虫Hb-NJ、Hb-IGA和Sc-All共生菌的相对抑制率分别为67.1%、39.3%和41.7%,10 d时4种(品系)昆虫病原线虫共生菌对M.incognita的孵化率和抑制率均无显著性差异(p0.05)。4种(品系)昆虫病原线虫共生菌的20×和50×稀释液对M.incognita卵孵化没有明显的抑制作用。基于以上结果,Hb-NJ的共生细菌可以通过抑制南方根结线虫的卵孵化导致线虫群体下降而达到防治线虫的目的,因此是一种潜在的生物杀线虫剂。     

植物激素响应和调控丛枝菌根共生研究进展

【目的】丛枝菌根是土壤中的丛枝菌真菌（arbuscular mycorrhizal,AM）与大多数陆地植物根系形成的互惠共生体。丛枝菌根的形成过程是一系列信号交换和转导的结果,受到很多基因的程序化表达调控。植物激素作为重要的信号物质被证实能够参与调控植物与AM真菌的互作过程。本文简述了植物激素在调控丛枝菌根形成的作用机理,为激素调控丛枝菌根形成的研究与应用提供理论线索。主要进展外源施加低浓度的生长素和脱落酸能够促进丛枝菌根共生,而外源施加赤霉素能够显著抑制丛枝菌根中丛枝的形成;内源缺失赤霉素,脱落酸以及油菜素内酯会抑制丛枝菌根共生;茉莉酸合成突变体推迟丛枝菌根形成;独脚金内酯合成、转运以及受体突变体都会抑制丛枝菌根共生;生长素以及脱落酸受体表达量降低会抑制丛枝菌根共生。但是生长素信号受体的降低表达不仅能够显著抑制丛枝菌根的形成还能显著抑制丛枝细胞的正常发育,而植物脱落酸信号受体表达降低突变体中丛枝细胞发育正常。研究展望激素如何调控丛枝菌根共生的研究仍处于起步阶段。随着转基因和基因编辑技术（如Crispr/cas9系统介导的基因敲除技术）的快速发展以及通过菌根植物的基因组、转录组、蛋白质和代谢组数据的挖掘,丛枝菌根共生中的众多科学问题以及与其他植物-微生物互作系统等问题都将一一得到解答。     

铬稳定同位素在丛枝菌根蒲公英中的分馏及根外菌丝对铬的吸收

As common soil fungi that form symbioses with most terrestrial plants,arbuscular mycorrhizal(AM) fungi play an important role in plant adaptation to chromium(Cr) contamination.However,little information is available on the underlying mechanisms of AM symbiosis on plant Cr resistance.In this study,dandelion(Taraxacum platypecidum Diels.) was grown with and without inoculation of the AM fungus Rhizophagus irregularis and Cr uptake by extraradical mycelium(ERM) was investigated by a compartmented cultivation system using a Cr stable isotope tracer.The results indicated that AM symbiosis increased plant dry weights and P concentrations but decreased shoot Cr concentrations.Using the Cr stable isotope tracer technology,the work provided possible evidences of Cr uptake and transport by ERM,and confirmed the enhancement of root Cr stabilization by AM symbiosis.This study also indicated an enrichment of lighter Cr isotopes in shoots during Cr translocation from roots to shoots in mycorrhizal plants.     

胶膜菌属真菌与兰科植物的共生体系建立

为建立兰科植物与菌根真菌的共生体系,本研究筛选出适宜的共生培养基,采用ITS-rDNA分析鉴定了6株菌根真菌,并将6株菌与兰科植物共生培养,利用台盼蓝染色法检验共生体是否建立。结果表明,2.5 g·L~(-1)燕麦琼脂培养基为树兰和胶膜菌属真菌共生的最适宜培养基,供试兰科植物中仅树兰可与6株胶膜菌属真菌共生,其中一株美孢胶膜菌(Tco 2)促进树兰种子萌发和原球茎发育的效果最好。本研究筛选出可促进树兰高效萌发成苗的共生真菌和培养基,为真菌与植物共生关系研究提供了良好的试验系统,为树兰的生产繁殖奠定了基础,对保护兰科植物物种资源具有重要意义。     

Specific flavonoids as interconnecting signals in the tripartite symbiosis formed by arbuscular mycorrhizal fungi, Bradyrhizobium japonicum (Kirchner) Jordan and soybean (Glycine max (L.) Merr.)

Many legume plants benefit from the tripartite symbiosis of arbuscular mycorrhizal fungi (AMF) and rhizobia. Beneficial effects for the plant have been assumed to rely on increased P supply through the mycorrhizas. Recently, we demonstrated that P does not regulate the establishment of the tripartite symbiosis. Flavonoids appear to play a role as early signals for both rhizobia and AMF. Four soybean lines known to express different concentrations of the isoflavones genistein, daidzein and glycitein in the seed were used to test three hypotheses: (i) The establishment of the tripartite symbiosis is not dependent of a nutrient mediated effect; (ii) There is a positive correlation between seed isoflavone concentrations of different soybean lines and the progress of the tripartite symbiosis; (iii) Specific flavonoids control the establishment of the tripartite symbiosis in that a change in flavonoid root accumulation resulting from the development of one microbial partner can stimulate colonization of soybean roots by the other. Disturbed versus undisturbed soil treatments were produced to vary the potential for indigenous AMF colonization of soybean. In contrast, the potential for Bradyrhizobium was kept identical in both soil disturbance treatments. The uptake of P and Zn and the concentration of flavonoids in mycorrhizal soybean roots at 10 d after emergence were analysed either separately of Bradyrhizobium or in context of the tripartite symbiosis. Zinc nutrition did not differ between AMF treatments which supports the first hypothesis. The concentration of daidzein was at least four times greater in the root than in the seed reaching 3958±249 μg g⁻¹ dry across soybean lines. Coumestrol, which was absent in the seed, was synthesized to reach 2154±64 μg g⁻¹ dry. Conversely, the concentration of genistein was approximately three times smaller in the root that in the seed (301±15 μg g⁻¹ dry), while glycitein and formononetin were never detected. The establishment of the tripartite symbiosis was identical across soybean lines which does not support the second hypothesis. Concentrations of flavonoids were significantly greater in roots under disturbed soil, for which both symbioses were not as developed as in plants from undisturbed soil. This clearly supports the third hypothesis. This research provides the first data linking the function of different flavonoids to the establishment of the tripartite symbiosis, and suggests that these compounds are produced and released into the rhizosphere as a function of the colonization process.     

基于共生视角的河北省乡村地域多功能空间格局与分区调控

精准识别乡村地域多功能空间异质性特征及实现分区调控有助于巩固脱贫攻坚成果与乡村振兴的有效衔接,进而实现区域之间、城乡之间的协调发展。以河北省121个县（含县级市）为研究单元,从农业生产功能、非农生产功能、居住生活功能、生态保障功能四个维度,构建乡村地域多功能评价指标体系,利用综合评价法测度乡村地域功能值,运用ArcGIS自然间断点和全局空间自相关模型,揭示河北省乡村地域多功能的空间分异特征;基于共生理论和共生模型,探究乡村地域多功能之间的共生模式,综合乡村地域主导功能、短板功能以及共生模式,实现乡村地域空间功能分区调控。研究表明：1）河北省乡村地域多功能空间分异和集聚特性十分明显。2）河北省乡村地域多功能间存在正向非对称互利共生、寄生关系等多种共生模式。3）将河北省乡村地域划分为极化发展区、主导发展区、欠缺发展区、综合发展区共4种一级功能区,细分16种二级功能区,并提出各类功能区优化发展策略。研究表明乡村地域多功能具有一定的空间异质性,功能间存在多种共生关系,在乡村地域发展决策中应明晰其空间分异特征,把握乡村地域多功能间的内在共生关系,从而提供更为科学的分区优化策略。     

Accumulation of specific flavonoids in soybean (Glycine max (L.) Merr.) as a function of the early tripartite symbiosis with arbuscular mycorrhizal fungi and Bradyrhizobium japonicum (Kirchner) Jordan

This study is the first report assessing the effect of soil inoculation on the signalling interaction of Bradyrhizobium japonicum, arbuscular mycorrhizal fungi (AMF) and soybean plants throughout the early stages of colonisation that lead to the tripartite symbiosis. In a study using soil disturbance to produce contrasting indigenous AMF treatments, the flavonoids daidzein, genistein and coumestrol were identified as possible signals for regulating the establishment of the tripartite symbiosis. However, it was unclear whether soil disturbance induced changes in flavonoid root accumulation other than through changing the potential for AMF colonization. In this study, soil treatments comprising all possible combinations of AMF and B. japonicum were established to test whether (1) modifications in root flavonoid accumulation depend on the potential for AMF colonization, and (2) synthesis and accumulation of flavonoids in the roots change over time as a function of the early plant-microbial interactions that lead to the tripartite symbiosis. The study was comprised of two phases. First, maize was grown over 3-week periods to promote the development of the AM fungus Glomus clarum. Second, the interaction between soybean, G. clarum and B. japonicum was evaluated at 6, 10, 14 and 40 days after plant emergence. Root colonization by G. clarum had a positive effect on nodulation 14 days after emergence, producing, 30% more nodules which were 40% heavier than those on roots solely inoculated with B. japonicum. The tripartite symbiosis resulted in 23% more N₂ being fixed than did the simpler symbiosis between soybean and B. japonicum. The presence of both symbionts changed accumulation of flavonoids in roots. Daidzein and coumestrol increased with plant growth. However, development of the tripartite symbiosis caused a decrease in coumestrol; accumulation of daidzein, the most abundant flavonoid, was reduced in the presence of AMF.     

Enhancing of symbiotic efficiency and salinity tolerance of chickpea by phosphorus supply

This study aims to highlight the beneficial effect of the phosphorus on enhancing of growth plant, the efficiency of use rhizobial symbiosis and ionic partition in chickpea grown under salt stress. Exposure of plants to salt stress (0, 150 mM of NaCl) caused ionic imbalance, which resulted in increased Na⁺ and P and reduced K⁺ contents in the leaves and root. Indeed, stressed plants showed decrease of plant growth and phosphorus use efficiency. The efficiency use of rhizobial symbiosis was also affected by salinity. However, addition of two different level of phosphorus (37 and 55 mM) to saline soil increased significantly availability of P in plant organs. Specially, the (150 mM NaCl?×?37 mM P) mixture increased (33%) phosphorus use efficiency, induced better nodulation and increased plant biomass which results in the high efficiency in use of the rhizobial symbiosis. Our findings suggest that the combination of low level of P to saline soil presumably improved the tolerance of chickpea plant to salinity.

Abbreviations: phosphorus (P); phosphorus use efficiency (PUE); biological nitrogen fixation (BNF); plant dry weight (PDW); yeast extract mannitol (YEM); efficiency in use of the rhizobial symbiosis (EURS); shoot dry weight (SDW); symbiotic nitrogen fixation (SNF).     

Comparative salinity tolerance of symbiotically dependent and nitrogen-fed pigeonpea (Cajanus cajan) and its wild relative Atylosia platycarpa

Summary Once symbiosis between the pigeonpea cultivar ICPL 227 and the Rhizobium sp. strain IC 3024 is established, it is efficient in fixing N₂ under saline conditions and can support growth comparable to N-fed plants in growth media with up to 6 dS m^-1 salinity. However, the early stages of establishment of the pigeonpea-IC 3024 symbiotic system have proved sensitive to salinity. The present study showed that the number of nodules was markedly reduced at 8 dS m^-1 salinity; however, nodule development and functioning were not affected by salinity in the pigeonpea-IC 3024 symbiosis. The symbiotic system of Atylosia platycarpa and Rhizobium sp. strain IC 3087 was established successfully even at 12 dS m^-1 and supported growth comparable to that of N-fed plants. P levels in leaves were increased under saline conditions in N-fed and N₂-fixing pigeonpea and A. platycarpa. There were no consistent differences in the leaf Na and chloride levels between N-fed and N₂-fixing plants of pigeonpea and A. platycarpa. The present study suggests that the rhizobial symbiosis may not be a necessary factor for initial screening of pigeonpea and related wild species for salinity tolerance.Submitted as JA No. 964 by the International Crops Research Institute for the Semi-Arid Tropics (ICRISAT)     

The influence of physical soil conditions on the formation of root nodules of Melilotus officinalis in the montane zone of Rocky Mountain National Park

Exotic invasion is a key threat to native biological diversity, second only to habitat degradation. Melilotus officinalis is an exotic species that thrives in areas of anthropogenic disturbances and low nutrient availability. Typically, natural disturbance facilitates native species establishment and maintains species diversity; however, anthropogenic disturbance facilitates exotic species establishment. M. officinalis functions as a competitor in the montane communities because of its symbiosis with Rhizobium bacteria, a symbiosis that allows the plant to acquire nitrogen. Although the ability to fix nitrogen permits M. officinalis to grow in nitrogen depleted soils, the soil must have a microclimate that is favorable to symbiosis and nodulation. We analyzed abiotic soil characteristics in Rocky Mountain National Park to determine if nodulation was related to soil texture, as well as in the mid-range level of soil and temperatures. We found that nodules on plant specimens showed a positive correlation with soil moisture and temperature, and occurred in a specific range of moderate moisture and temperature. Soil texture was not correlated to nodule formation.     

Conditions for successful Rhizobium-legume symbiosis in saline environments

Summary The Rhizobium-legume symbiosis in arid ecosystems is particularly important for locations where the area of saline soils is increasing and becoming a threat to plant productivity. Legumes, which are usually present in arid ecosystems, may be adapted to fix more N₂ under saline conditions than legumes grown in other habitats.Legumes are known to be either sensitive or moderately resistant to salinity. The salt sensitivity can be attributed to toxic ion accumulations in different plant tissues, which disturb some enzyme activities.Among the basic selection criteria for salt-tolerant legumes and rhizobia are genetic variability within species with respect to salt tolerance, correlation between accumulations of organic solutes (e. g., glycine betaine, proline betaine, and proline) and salt tolerance, and good relationships between ion distribution and compartmentation, and structural adaptations in the legumes.Salt stress reduces the nodulation of legumes by inhibiting the very early symbiotic events. Levels of salinity that inhibit the symbiosis between legumes and rhizobia are different from those that inhibit the growth of the individual symbionts. The poor symbiotic performance of some legumes under saline conditions is not due to salt limitations on the growth of rhizobia.Prerequisites for a successful Rhizobium-legume symbiosis in saline environments include rhizobial colonization and invasion of the rhizosphere, root-hair infection, and the formation of effective salt-tolerant nodules.The possibility of exploring the Rhizobium-legume symbiosis to improve the productivity of saline soils is reviewed in this paper.