丛枝菌根真菌侵染指标与植物促生效应相关性分析

为探讨不同丛枝菌根真菌(Arbuscular mycorrhizal fungi,AMF)生长特性与功能(植物生长和养分吸收)的相关性。采用分室根箱装置,以玉米(Zea mays L.)和紫花苜蓿(Medicago sativa L.)为宿主植物,选取7种AMF:摩西斗管囊霉Funneliformis mosseae、变形球囊霉Glomus versiforme、根内根孢囊霉Rhizophagus intraradices、幼套近明球囊霉Claroideoglomus etunicatum、近明球囊霉C.claroideum、细凹无梗囊霉Acaulospora scrobiculata、黏屑多样孢囊霉Diversispora spurca,以不接种为对照进行温室盆栽试验,测定菌根侵染率、根外菌丝密度、植物地上部生物量、磷/锌吸收量、植物根系AMF gDNA丰度以及玉米根系ZmPht1;6的相对表达量。结果表明:接种F.mosseae、R.intraradices、G.versiforme、C.etunicatum的玉米和紫花苜蓿根系侵染率及根外菌丝密度较高,对植株生长和磷、锌吸收均表现为正效应;C.claroideum、A.scrobiculata、D.spurca根系侵染率和根外菌丝密度较低,C.claroideum对紫花苜蓿生长和磷吸收表现为促进效应,而对玉米表现出抑制效应,后两者对植株生长和磷、锌吸收无显著效应或抑制作用;AMF的生长指标(菌根侵染率和根外菌丝密度)与菌根生长效应以及磷、锌吸收效应之间均具有较高的正相关性,根系AMF总侵染率对玉米菌根生长效应、磷/锌吸收效应变异的解释量分别为79.0%,77.6%和74.1%;菌丝侵染率对紫花苜蓿菌根生长效应、磷/锌吸收效应变异的解释量分别为76.5%,72.6%和74.0%;此外,仅紫花苜蓿根系AMF gDNA丰度与根系总侵染率显著正相关,玉米根系ZmPht1;6基因的相对表达量与菌根磷吸收效应显著正相关。综上,AMF的侵染指标显著影响植物生长和养分吸收效应,AMF gDNA丰度可作为表示AMF生长的指标,但因植物而异,玉米根系ZmPht1;6的相对表达量在一定程度上可反映AMF吸磷能力。     

AM fungi ameliorates growth, yield and nutrient uptake in Cicer arietinum L. Under salt stress

A pot experiment was performed to see the effect of two indigenous arbuscular mycorrhizal (AM) fungi Glomus mosseae and Acaulospora laevis, alone and in combination on growth, biomass and mineral nutrition of Cicer arietinum under different salinity levels imposed by 4, 8, and 12 dS/m EC solution (sodium chloride, calcium chloride and sodium sulphate). All AM inoculated plants showed significant increment in growth, biomass, mineral nutrition and yield over control. The extent of bioinoculants response on plant growth as well as root colonization decreases with the increase in the level of salinity. Among all the growth parameters plant height (26.4 ± 1.14 cm), root length (13.4 ± 1.67 cm), total chlorophyll (2.33 ± 0.02 mg/100 mg f. wt), root colonization (41.6 ± 2.70%) and AM spore number (63.8 ± 1.78 per 10 gm soil) were recorded highest in dual combination (G. mosseae and A. laevis) at 4 dS/m while fresh shoot (6.80 ± 0.67 gm) and dry shoot weight (0.96 ± 0.18 gm) was found maximum in G. mosseae at the same concentration of salinity. Greater Phosphorus (P) acquisition and yield was observed at 4 dS/m with dual combination (G. mosseae and A. laevis) that possibly be responsible to protect plants from salt stress. Although Nitrogen (N), Potassium (K) and Sodium (Na) contents also declined with increasing salinity. Overall results showed that mycorrhizal colonization improves host plant mineral concentration and thereby increases the growth, yield and nutrient uptake of C. arietinum ameliorating the harmful effect at salinity stress.     

AM真菌和磷对小马安羊蹄甲幼苗生长的影响

丛枝菌根(arbuscular mycorrhizal,AM)真菌在退化生态系统恢复与重建实践中具有重要作用。采用盆栽模拟方法,重点分析不同土壤磷条件下小马鞍羊蹄甲(Bauhinia faberi)幼苗接种AM真菌后,幼苗的形态、生物量积累、菌根侵染率和菌根效应(mycorrhizal growth response, MGR)在一个生长季内的动态变化。结果表明,Glomus mosseae和 Glomus coronatum能较好地侵染幼苗,两种AM真菌显著地增加幼苗根系、叶片数和生物量;接种AM真菌显著影响幼苗的生物量分配,而土壤磷对幼苗的生物量分配影响不明显,AM真菌和土壤磷对幼苗生长的交互作用显著;G. mosseae是小马鞍羊蹄甲的优势AM菌,其接种的幼苗根长、叶片数、生物量、侵染率和菌根效应都显著高于G. coronatum处理的幼苗;菌根效应显著,接种AM真菌能有缓解土壤磷素缺乏的限制作用,且随着苗龄增大促生作用表现更为明显。不同AM菌种对小马鞍羊蹄甲幼苗生长的促生作用表现出的差异,提示在多元资源限制的干旱贫瘠环境中进行生物修复须为目标恢复物种筛选出高效的优势AM真菌。     

Interacted Effect of Arbuscular Mycorrhizal Fungi and Polyamines on Root System Architecture of Citrus Seedlings

Either arbuscular mycorrhizal fungi (AMF) or polyamines (PAs) may change root system architecture (RSA) of plants, whereas the interaction of AMF and PAs on RSA remains unclear. In the present study, we studied the interaction between AMF (Paraglomus occultum) and exogenous PAs, including putrescine (Put), spermidine (Spd) and spermine (Spm) on mycorrhizal development of different parts of root system, plant growth, RSA and carbohydrate concentrations of 6-m-old citrus (Citrus tangerine Hort. ex Tanaka) seedlings. After 14 wk of PAs application, PA-treated mycorrhizal seedlings exhibited better mycorrhizal colonization and numbers of vesicles, arbuscules, and entry points, and the best mycorrhizal status of taproot, first-, second-, and third-order lateral roots was respectively found in mycorrhizal seedlings supplied with Put, Spd and Spm, suggesting that PAs might act as a regulated factor of mycorrhizal development through transformation of root sucrose more into glucose for sustaining mycorrhizal development. AMF usually notably increases RSA traits (taproot length, total length, average diameter, projected area, surface area, volume, and number of first-, second-, and third-order lateral roots) of only PA-treated seedlings. Among the three PA species, greater positive effects on RSA change and plant biomass increment of the seedlings generally rank as Spd>Spm>Put, irrespective of whether or not AMF colonization. PAs significantly changed the RSA traits in mycorrhizal but not in non-mycorrhizal seedlings. It suggests that the application of PAs (especially Spd) to AMF plants would optimize RSA of citrus seedlings, thus increasing plant growth (shoot and root dry weight).     

盐分和重金属胁迫下AM真菌对小果白刺生长的影响

【目的】探究接种丛枝菌根（Arbuscular mycorrhizal,AM）真菌对不同程度盐分和重金属胁迫下小果白刺Nitraria sibirica Pall.生长的影响,为重金属污染盐渍化土壤的植物-微生物联合修复提供科学依据和数据支持。【方法】采用温室盆栽的方法,模拟不同程度重金属Cd污染(干土中含0、2、5 mg·kg^-1 Cd)NaCl型(干土中含0、1.5 g·kg^-1 Na⁺)盐渍化土壤（Cd0Na0、Cd0Na1.5、Cd2Na0、Cd2Na1.5、Cd5Na0、Ca5Na1.5）,研究接种AM真菌Funneliformis mosseae对Cd和NaCl胁迫下小果白刺的菌根侵染、元素吸收、离子平衡、生物量、Na⁺和Cd含量与吸收的影响。【结果】在重金属Cd和NaCl胁迫下,接种F. mosseae的植物根系平均菌根侵染率为12.68%～21.90%。与不接种CK相比,接种AM真菌使不同处理小果白刺总干质量增加101.35%～215.29%;地上部矿质营养元素增加47.55%～21...     

AM真菌和水杨酸对草莓耐盐性的影响

 【目的】探索AM真菌与外源水杨酸SA提高植物耐盐性的协同效应。【方法】于温室盆栽条件下试验了丛枝菌根（AM）真菌摩西球囊霉（Glomus mosseae）和外源SA对草莓（Fragaria×ananassa Duch.品种：哈尼）耐盐性的影响。【结果】接种摩西球囊霉、施加外源SA、或接种摩西球囊霉+SA处理都能显著增加草莓植株叶片和根内K和叶绿素含量、降低Na和丙二醛的含量,而以G.m+SA处理效果最佳。NaCl 6 g?L-1胁迫下,接种摩西球囊霉和外源SA处理能显著提高草莓叶片SOD、POD和CAT酶活性、促进植株生长。接种AM真菌配合外源SA处理提高草莓耐盐性的效果最明显。【结论】在一定条件下接种AM真菌配合施用外源SA能协同提高植物耐盐性。     

干旱条件下AM真菌对植物生长和土壤水稳定性团聚体的影响

采用分室培养系统,模拟正常水分和干旱胁迫两种环境条件,探讨不同丛枝菌根真菌(arbuscular mycorrhizal fungi,AMF)对紫花苜蓿(Medicago sativa L.)生长和土壤水稳性团聚体的影响.试验条件下,Glomus intraradices对苜蓿根系的侵染率均显著高于Acaulospora scrobiculata和Diversispora spurcum接种处理.正常水分条件下,供试AM真菌均能显著提高植株生物量及磷浓度.干旱胁迫显著抑制了植株生长和菌根共生体发育,总体上菌根共生体对植株生长没有明显影响,接种D.spurcum甚至趋于降低植株生物量;同时,仅有G.intraradices显著提高了植株磷浓度.AM真菌主要影响到＞2mm的水稳性团聚体数量,以G.intraradices作用效果最为显著.在菌丝室中,G.intraradices显著提高了总球囊霉素含量.研究表明AM真菌对土壤大团聚体形成具有积极作用,而菌根效应因土壤水分条件和不同菌种而异,干旱胁迫下仅有G.intraradices对土壤结构和植物生长表现出显著积极作用.在应用菌根技术治理退化土壤时,需要选用抗逆性强共生效率高的菌株,对于不同AM真菌抗逆性差异的生物学与遗传学基础尚需进一步研究.     

接种丛枝菌根真菌对棉花生长和黄萎病的影响

研究了接种两种丛枝菌根真菌(Glomus mosseae和Glomus etunicatum)对棉花生长和对黄萎病的影响,并且探讨了丛枝菌根真菌诱导植物抗病性的可能机制.结果表明,接种丛枝菌根真菌后能促进棉花的营养生长,增加叶绿素的含量,促进光合作用的进行;在先接种丛枝菌根真菌然后接种黄萎病原菌的情况下,可以增加棉花根内总酚含量,诱导棉花根内过氧化物酶(POD)的合成,提高POD的活性,明显降低棉花黄萎病的发病率和发病指数.另一方面,当黄萎病原菌侵袭时,丛枝菌根真菌对根的侵染率降低,说明两者之间存在着一定的相互关系.丛枝菌根的形成对于棉花植株产生了多方面的影响,而丛枝菌根真菌诱导植物抗病性的机理是一个关于植物组织结构和生理生化发生变化的复杂过程,与改善植物营养、与病原物竞争光合产物和侵染位点、激活植物防御机制等方面相关.     

水分胁迫下AM真菌和根瘤菌对沙打旺生长及养分吸收的影响

利用温室盆栽试验研究水分胁迫下接种丛枝菌根（Arbuscular mycorrhizal,AM）真菌和根瘤菌（Rhizobium meliloti）对沙打旺(Astragalus adsurgens Pall.) 生长和养分吸收的影响。在土壤相对含水量65%和35%条件下,分别设不接种（对照）、单接根瘤菌、单接摩西球囊霉(Glomus mosseae)和双接根瘤菌与摩西球囊霉等4个处理。结果发现：干旱胁迫显著抑制沙打旺AM真菌侵染率（P<0.05）,而接种根瘤菌在两种水分条件下均显著促进摩西球囊霉对沙打旺根系的侵染（P<0.05）。接种AM真菌不仅显著提高沙打旺对P的吸收（P<0.05）,而且明显促进根瘤的生长。无论是在干旱条件下或是在正常供水条件下,双接根瘤菌与摩西球囊霉处理对沙打旺生长及养分吸收的效应显著高于单接菌处理,植株地上部、地下部生物量以及N、P、K等吸收量均为最大。结果表明：AM真菌与根瘤菌双接种技术在干旱、半干旱区受损生态系统的植被恢复中具有一定的应用潜力。     

三种根系分泌脂肪酸对花生生长和土壤酶活性的影响

为了探讨花生连作后土壤中脂肪酸类物质的累积与花生连作障碍间的关系,为花生连作障碍机理的研究提供新的理论依据,以田间土壤为介质,采用盆栽试验的方法研究了花生根系分泌物中3种长链脂肪酸,即:豆蔻酸、软脂酸和硬脂酸的混合物,对花生植株生长、产量和土壤酶活性的影响。结果表明,当土壤中脂肪酸的初始含量较低时(80 mg/kg土),对花生植株的生长和产量有微弱的促进作用(P > 0.05),当土壤中脂肪酸的初始含量较高时(160 mg/kg土和240 mg/kg土),显著抑制了花生植株的生长和产量(P < 0.05)。叶片叶绿素含量、根系活力、土壤酶(蔗糖酶、脲酶、磷酸酶)活性在低脂肪酸含量处理下升高,在高脂肪酸含量处理下显著降低(P < 0.001)。光合产物、根际有效养分的减少和根系养分吸收能力的降低,可能是导致花生植株生长和产量降低的原因之一。花生连作土壤中豆蔻酸、软脂酸和硬脂酸的累积与花生的连作障碍有着密切关系。     

土著菌根真菌和混生植物对羊草生长和磷营养的影响

植物种间相互作用直接影响植物生长、根系可塑性及养分吸收,而与植物共生的丛枝菌根真菌可以改变植物个体和种间养分资源的分配,具有协调种间竞争的潜力.以我国北方草甸草原建群种羊草(Leymus chinensis)和混生植物紫花苜蓿(Medicago sativa)及独行菜(Lepidium spetalum)为供试植物,通过模拟盆栽试验,研究了土著菌根真菌和混生植物对羊草生长、根系形态及磷营养的影响.试验结果表明,土著菌根真菌能够与羊草及紫花苜蓿形成良好共生,而独行菜根内基本未形成菌根共生结构.土著菌根真菌显著降低了羊草及独行菜的生物量,但促进了紫花苜蓿的生长;混种紫花苜蓿显著促进了羊草的生长,而混种独行菜则显著抑制了羊草的生长.土著菌根真菌对羊草根系形态的影响表现出与植株生物量类似的趋势,但不同混生植物对羊草根系生长均无显著影响.土著菌根真菌和混生植物对羊草植株磷含量均无显著影响.与混生植物相比,羊草具有较高的比根长和磷吸收能力,这也解释了其负向菌根依赖性.研究证实了菌根真菌和植物种间相互作用均是影响草原优势植物生长和根系发育的重要因素,深入研究其交互作用对于科学管理草地生态系统,维持植物群落的稳定性和生态系统生产力具有重要意义.     

长期施用氮肥和磷肥对东北黑土丛枝菌根真菌群落组成的影响

【目的】丛枝菌根(Arbuscular mycorrhizae,AM)真菌在促进作物养分吸收、提高作物抗病和抗逆性等方面具有重要意义,探讨长期施用化学氮肥和磷肥对东北黑土AM真菌的影响及其主效环境因子,为进一步揭示AM真菌对化肥的响应机制,指导农田施肥以及利用AM真菌提高土壤养分有效性提供依据。【方法】以长期定位试验为平台,选取5种不同处理:不施肥(CK),单施常量氮肥(N_1),混施常量氮肥和磷肥(N_1P_1),单施2倍常量氮肥(N_2),混施2倍常量氮肥和磷肥(N_2P_2)。采用Illumina Miseq高通量测序技术研究连续施用37年氮肥和磷肥的AM真菌群落组成差异,并对AM真菌群落组成与环境因子进行相关性分析。【结果】随着氮、磷施用量的增加,黑土p H和速效钾含量显著降低,而全氮、硝态氮、铵态氮和有机质含量显著提高。单施氮肥(N_1和N_2)对黑土中AM真菌多样性影响不显著(P0.05);然而氮、磷混施(N_1P_1和N_2P_2)显著降低黑土中AM真菌多样性(P0.05)。土壤中AM真菌以Glomeraceae科为主,占AM真菌45.5%。在属水平上,施肥降低Funneliformis和Septoglomus丰度,而提高Paraglomus丰度;在N_1和N_2基础上施磷显著提高Glomus和Funneliformis丰度,而降低Gigaspora和Paraglomus的丰度。非度量多维度分析表明,长期施用氮、磷肥改变了土壤中AM真菌群落组成。不施肥处理、单施氮肥处理和氮、磷混施处理AM真菌群落差异显著,且磷肥影响较为显著。冗余分析表明,土壤p H,有效磷含量是影响黑土中AM真菌群落组成的主效环境因子(P0.05)。【结论】长期施用氮肥以及氮、磷肥混施改变了黑土中AM真菌群落组成,单施氮肥对黑土中AM真菌多样性影响不大,而氮、磷肥混施降低其多样性,施肥导致的土壤p H和有效磷含量变化是主要因素。     

丛枝菌根真菌对红树植物耐盐性的影响

为研究丛枝菌根真菌(Arbuscular mycorrhizal fungi,AMF)对红树植物耐盐性的影响,采用盆栽试验方法,利用本研究室分离得到的一株AMF侵染尖瓣海莲幼苗,以非侵染植株为对照,检测在不同程度盐胁迫下植物的根系电导率、脯氨酸、丙二醛(MDA)、抗氧化酶系活力的变化。结果表明,在高浓度盐胁迫下,AMF能够显著降低植物根系电导率、脯氨酸含量、MDA含量,保持超氧化物歧化酶(SOD)、过氧化氢酶(CAT)、过氧化物酶(POD)活力较低的增长幅度,在一定程度上保护了红树植物根系细胞膜系统,保持细胞渗透平衡,有效缓解盐胁迫对植物根系的伤害,提高了植物的耐盐性。     

哀牢山亚热带次生林AM真菌的初步研究*

 哀牢山分布着目前我国面积最大、保存最完整的亚热带山地湿性常绿阔叶林。为摸清该地的丛枝菌根真菌群落结构和多样性现状，采用碱离解-锥虫兰染色法和湿筛法，对哀牢山亚热带次生林中丛枝菌根真菌的侵染率（colonization level）、孢子密度（Spore density）、物种丰富度（species richness）、频度（species frequency）及AMF的结构类型进行了研究。从5个样点不同植物的根围土壤中分离到了隶属于球囊霉属（Glomus）、巨孢囊霉属 （Gigaspora）、盾巨孢囊霉属（Scutellospora）和无梗囊霉属（Acaulospora）的8种AM真菌。该地AMF侵染率为23.0%～89.0%；孢子密度为每100 g土壤27～42个；物种丰富度为2～6；在受侵染的植物中，82%的植物的AMF结构类型为Arum型，而Paris型只占18%；球囊霉属（Glomus）和巨孢囊霉属（Gigaspora）的AM真菌是哀牢山亚热带次生林中出现频率较高的丛枝菌根真菌类群。     

AMF对镉污染条件下水稻抗逆性及根际固定性的影响

为研究丛枝菌根真菌对重金属Cd胁迫条件下水稻生长及生理过程的影响,选用两种丛枝菌根真菌(Arbuscularmy corrhizal fungi,AMF):摩西球囊霉(Glomus mosseae,GM)和根内球囊霉(Glomus intraradice,GI),接种在不同Cd浓度(0、0.5、1、2、5 mg·kg-1)的污染土壤中,研究两种菌剂对水稻株高、光合作用、抗逆生理过程以及Cd在植株地上及根系分配的影响。结果表明,AMF菌剂的接种显著减轻了Cd胁迫对水稻生长的抑制程度,GM组与GI组水稻株高分别比对照组提高了13.8%和10.3%,且菌剂处理有助于缓解Cd胁迫对水稻光合作用的抑制。在5 mg·kg-1Cd胁迫下,水稻叶片中MDA(丙二醛)含量显著降低,SOD(超氧化物歧化酶)活性和Pro(脯氨酸)的含量显著提高(P0.05)。两种菌剂处理下水稻对Cd的富集系数与转运系数均低于对照,表明AMF处理有助于缓解Cd对地上部分的毒害,并且促进了水稻对Cd的根际固定化过程,抑制了Cd向地上部分转移的趋势。     

纳米银和外源丛枝菌根真菌对甜高粱叶绿素荧光诱导动力学特性的影响

纳米银是应用最广泛的人工纳米材料之一,具有一定的生物毒性。丛枝菌根真菌(arbuscular mycorr-hizal fungi, AMF)能与陆地上80%的植物形成互惠共生关系,并能改善植物对矿质营养的吸收,促进光合作用,提高抗逆性。而纳米银与AMF共同作用对植物叶绿素荧光特性的影响尚不清楚。本实验选择能源植物甜高粱为供试植物,在未灭菌土壤中利用温室盆栽试验,研究了不同纳米银水平下接种外源AMF对甜高粱叶绿素荧光诱导动力学特性的影响。结果表明,纳米银对外源AMF有一定毒性,抑制了菌根侵染植物根系。纳米银施加浓度的增加造成了光系统Ⅱ(PSⅡ)供体侧受到伤害,结构被破坏;并且抑制了最大光化学效率(F_v/F_m)和PSⅡ潜在活性(F_v/F_o),降低了PSⅡ的光能效率;而接种外源AMF则可通过增加热耗散以减少对PSⅡ结构的破坏,对植物起到保护作用。研究证实,在未灭菌条件下,接种外源AMF可以缓解纳米银对甜高粱的植物毒性,其效应与纳米银剂量有关。     

Changes in fungal community and diversity in strawberry rhizosphere soil after 12 years in the greenhouse

Soil fungi play a very important role in the soil ecological environment. In agricultural production, long-term monoculture and continuous cropping lead to changes in fungal community diversity. However, the effects of long-term monoculture and continuous cropping on strawberry plant health and fungal community diversity have not been elucidated. In this study, using high-throughput sequencing (HTS), we compared the fungal community and diversity of strawberry rhizosphere soil after various durations of continuous cropping (0, 2, 4, 6, 8, 10 and 12 years). The results showed that soil fungal diversity increased with consecutive cropping years. Specifically, the soil-borne disease pathogens Fusarium and Guehomyces were significantly increased after strawberry continuous cropping, and the abundance of nematicidal (Arthrobotrys) fungi decreased from the fourth year of continuous cropping. The results of correlation analysis suggest that these three genera might be key fungi that contribute to the changes in soil properties that occur during continuous cropping. In addition, physicochemical property analysis showed that the soil nutrient content began to decline after the fourth year of continuous cropping. Spearman's correlation analysis showed that soil pH, available potassium (AK) and ammonium nitrogen (NH₄⁺-N) were the most important edaphic factors leading to contrasting beneficial and pathogenic associations across consecutive strawberry cropping systems.     

The Effects of Arbuscular Mycorrhizal Fungi on Reactive Oxyradical Scavenging System of Tomato Under Salt Tolerance

The effects of arbuscular mycorrhizal fungi （AMF）, Glomus mosseae, on oxygen radical scavenging system of tomato under salt stress were studied in potted culture experiments. The response of tomato （Lycopersieon eseulentum L.） cultivar Zhongza 9 seedlings with AMF inoculation and control to salt stress （0, 0.5 and 1.0% NaCl solution, respectively） was investigated. The results showed that the salt stress significantly reduced the dry matter content of roots, stems and leaves, and also the leaf area as compared with the control treatment. However, arbuscular mycorrhizal-inoculated （AM） significantly improved the dry matter and the leaf area in the salt-stressed plants. The effect of AMF on dry matter was more pronounced in aerial bromass than in root biomass which might be due to AM colonization. The activities of SOD, POD, ASA-POD, and CAT in leaves and roots of mycorrhizal and non-mycorrhizal treatment of tomato plants were increased and had different rules under different NaCl concentrations （solution of 0, 0.5 and 1% NaCl）, but all enzymes had a rise in the beginning of treatment under salt stress conditions. The AMF did not change the rule of tomato itself under salt stress, but AMF increased these enzyme activities in different levels. The AMF treatment significantly increased SOD, POD and ASA-POD activities in leaves and roots, whereas it had little effects on CAT in root. O2- production rate and MDA content in leaves increased continuously, which showed a positive line correlation with salt stress concentration. O2- production rate and MDA content in tomato plants significantly decreased by AM treatment compared with nonmycorrhizal treatment. In conclusion, AM could alleviate the growth limitations imposed by saline conditions, and thereby play a very important role in promoting plant growth under salt stress in tomato.     

新疆伊犁野生植物VA菌根真菌及其生态分布

对新疆伊犁地区8种野生植物的VA菌根真菌进行了分离鉴定,并对其生态分布进行了研究。结果表明,在8种野生植物根围土壤中均有VA菌根真菌的孢子分布,从中分离并鉴定出丽孢无梗囊霉(A cau losp oraeleg ans G erdem ann&T rappe)、蜜色无梗囊霉(A cau losp ora m ellea Spa in&Schenck)、苏格兰球囊霉(G lom us ca le-d on ium N ico lson&G erdem ann)、缩球囊霉(G lom us constrictum T rappe)、地球囊霉(G lom us g eosp orum N ico lson&G erdem ann)、台湾球囊霉(G lom us f orm osanum W u&Chen)和白色球囊霉(G lom us a lbidum W a lker&R hodes)7种VA菌根真菌,其中缩球囊霉和地球囊霉的出现频率较高,为优势菌种;同一菌种在不同宿主上的种群频度存在差异,表现出较强的VA菌根真菌与宿主植物之间的选择性;在不同地区的同种宿主上,土壤中孢子数量与平均侵染率亦存在差异,并随海拔高度增加而递减,表现出VA菌根真菌对生态环境的适应性。     

盐胁迫下丛枝菌根真菌对番茄细胞膜透性及谷光甘肽过氧化物酶活性的影响

采用温室有机土盆栽试验研究了不同盐浓度(N aC l浓度分别为5和10 g/L)胁迫下,丛枝菌根真菌(AM F)对番茄氧自由基(O2.-)产生速率,丙二醛(M DA)含量,细胞膜透性,谷胱甘肽过氧化物酶(G SH-Px)活性和叶片相对含水量(RW C)等生理指标的影响。结果表明,在盐胁迫下,接种和未接种AM F的番茄均随盐浓度的增加和盐胁迫时间的延长,叶片和根系中M DA含量、叶片中O2.-产生速率和细胞膜透性持续增加,RW C下降;与未接种番茄相比,接种AM F能显著减少番茄植株叶片中M DA的积累,降低O2.-产生速率和细胞膜透性,增加RW C,因而减缓了盐胁迫对番茄细胞膜的伤害,增强了番茄的耐盐性。盐胁迫下,接种AM F番茄的G SH-Px活性显著高于未接种株,可见接种AM F增强了番茄叶片的G SH-Px活性,减轻了活性氧对植株细胞膜的伤害,提高了番茄的耐盐性。