低磷环境下接种丛枝菌根真菌促进紫花苜蓿生长和磷素吸收的机理

[目的]磷极易被土壤吸附和固定,导致土壤中磷有效性较低.研究接种丛枝菌根真菌(arbuscular mycorrhizal fungi,AMF)和低磷处理两者交互对紫花苜蓿生长和磷吸收的影响,为提高碱性土壤中磷肥利用率提供理论依据.[方法]以黄绵土和紫花苜蓿(Medicago sativa)为试验材料进行盆栽试验.在施...     

接种丛枝菌根真菌对甘薯生长的影响研究

温室盆栽试验研究 3种丛枝菌根真菌 (AM )对甘薯生长的影响结果表明 ,灭菌土壤条件下接种 3种AM真菌 (GlomusmosseaeBEG16 7GlomusintraradicesBEG14 1和Glomussp .WUM2 6 )均不同程度促进甘薯对P的吸收和植株生长 ,其中BEG16 7和BEG14 1对甘薯效应显著高于WUM2 6 ;各接种处理菌丝长度差异及琥珀酸脱氢酶(SDH)活性与其对甘薯的生长效应基本一致 ;接种BEG16 7和BEG14 1的生长效应无显著差异 ,但接种BEG16 7菌丝长度显著大于BEG14 1,其原因可能是BEG16 7菌丝活性低于BEG14 1所致。未灭菌土壤条件下接种 3种AM真菌对甘薯的生长效应不显著 ,而土著AM真菌繁殖体数量较多可能是影响其接种效果的主要原因。     

兰科菌根真菌对石斛组培苗的接种效应

从野生球花石斛(Dendrobium thyrsiflorum)根系中分离到Dt1、Dt2、Dt5、Dt6、Dt7、Dt8 共6株真菌,将其接种到铁皮石斛(Dendrobium candidum)和球花石斛组培苗的根系上,定期测定石斛苗的株数、株高、叶数、新芽数等指标,并与不接种的石斛苗进行比较。试验结果表明,Dt5号和Dt8号真菌的接种效果最好,地上植株和地下根系生长均良好,株数增多、株高增加、落叶减少,新芽和新根萌发,因此它们对于石斛组培苗的成功栽培具有实际应用价值。     

三种土壤上六种丛枝菌根真菌生长特征和接种效应

以分离于华北、华中和华南3个生态区及法国引进的丛枝菌根真菌为试验菌株,采用三室根箱培养的方法,研究了它们在华北、华中和华南3种典型土壤褐土、棕壤和红壤上的菌根形成、接种效应、磷吸收贡献和根外菌物量情况。结果表明,6种菌株在上述指标上存在显著的种间或生态型差异,土壤与菌株间存在显著的交互作用。6种菌株在3种土壤上都能与玉米形成菌根,在褐土和棕壤上大多数菌株在分离地所在地区土壤类型上的菌根侵染率较高,说明其对该土壤条件的适应性较强;在红壤强酸性土壤条件抑制了菌根真菌的侵染。菌株BEG168、BEG167、BEG151、BEG221和BEG141在褐土上,BEG151和BEG221在棕壤上,BEG168和BEG150在红壤上显著提高了玉米的生物量。在褐土和棕壤上,除BEG150外,BEG168、BEG167、BEG151、BEG221和BEG141能显著促进宿主吸磷;而在红壤上,BEG168和BEG141显著促进了宿主吸磷。若以真菌的根外菌物量作为衡量AM真菌菌株土壤生态适应性的指标,BEG141和BEG167是生态适应性强的菌株,为广幅生态型菌株;菌株BEG168和BEG151次之,前者在棕壤上适应性高,后者在红壤上适应性高。BEG150和BEG221生态适应性较窄,仅适应红壤或褐土,为窄幅生态型菌株。Glomus.etunicatum的两个生态型BEG168和BEG221在土壤生态适应性上差异很大,前者在两种土壤上收集到菌物量,而后者只在褐土上收集到菌物量。土壤条件可以决定丛枝菌根真菌的生长状况和功能。     

菌根对紫色土上间作玉米生长及磷素累积的影响

丛枝菌根真菌(arbuscular mycorrhizal fungi,AMF)在土壤与植物系统的磷素循环中发挥着关键的作用。本文通过盆栽模拟试验研究了不同AMF接种状况[不接种(NM)、接种Glomus mosseae(GM)、接种G.etunicatum(GE)]和玉米/大豆间作体系不同根系分隔方式(不分隔、尼龙网分隔、塑料膜分隔)对间作玉米植株生长及磷素吸收累积的影响。研究结果表明:GM处理下的间作玉米根系侵染率在不同根系分隔方式之间的差异不显著,而GE处理则在塑料膜分隔处理下对玉米的侵染率最高。接种不同AMF对间作玉米促生效果不同,GM和GE处理在不同根系分隔情况下表现出各自的优势,与未接种处理相比,GM处理能使玉米生物量、株高有一定程度增加并在根系不分隔处理下玉米磷吸收较多、生长较好;GE处理能使植株生物量有一定程度增加并在尼龙网分隔处理下的玉米磷吸收较多、生长较好。间作体系不同根系分隔方式对玉米的影响也不同,其中玉米地上部生物量在根系分隔处理下普遍小于不分隔处理,但根系生物量的大小情况则刚好相反。另外,无论何种接种状况,玉米根系磷含量及吸收量均以尼龙网分隔处理显著较高。而根系磷吸收效率则以接种G.mosseae且不分隔根系处理显著高于分隔处理。所有复合处理中,以接种G.etunicatum与尼龙网分隔根系组合处理对间作玉米的生长及磷素累积的促进作用最好,若应用于滇池流域,可望有效控制坡耕地土壤磷素的迁移。     

丛枝菌根和根瘤菌双接种对矿区土地复垦的生态效应

通过盆栽试验研究了山西省襄垣县矿区复垦土壤中接种丛枝菌根真菌和根瘤菌对三叶草的生长状况及土壤养分的影响.结果表明,双接种丛枝菌根和根瘤菌能显著提高菌根侵染率和土壤中孢子密度,促进三叶草干物质的积累和对氮、磷元素的吸收,促进三叶草对土壤养分的活化,提高土壤养分利用率,加速矿区生态恢复.     

煤矿区先锋植物猪屎豆接种丛枝菌根的效应研究

以煤矿尾矿区土著先锋植物猪屎豆(Crotalaria pallida Ait.)为研究对象,开展了3种基质配比、4种丛枝菌根接种后的效应研究.结果表明:(1)从宿主生物量、菌根侵染率及侵染强度、50 g干土中的孢子数、根系活力看,A4菌根是最适合梅州明山矿区先锋植物猪屎豆的优势菌种,菌剂与基质优势组合是A4B1;(2)不同菌种、植株及地上部/地下部对镉、锌、铜、镍、锰5种重金属元素的吸收-排斥效应是不同的.从镉元素看,与对照A5相比,A1、A3、A4菌根促进或抑制对镉吸收-排斥效应均达极显著差异水平,这3种菌根结合猪屎豆可作为明山废矿区镉污染丛枝菌根-植物联合修复的优势菌种;4种菌根对促进或阻止铜、锰吸收-排斥效应均不显著;(3)覆土少的(覆2 cm厚黄土于9 cm厚煤矸石上)相应高于不接种且覆土厚(覆7 cm厚黄土于4 cm厚煤矸石上)的,说明接种菌根具有抵消由于覆土少而导致的植株生物量降低的潜力,极大地节约了复垦费用,综合经济效益十分可观.     

V-A菌根对杜果实生苗吸收营养和生长的影响

在灭菌的土壤条件下,对杧果实生苗进行接种 V-A 菌根菌试验。结果V-A 菌根对苗木有明显的促进生长效应,接菌的株高、茎粗、植株干物重均比对照有明显的增加,叶片叶绿素含量、光合速率、根系活力也有所提高,而且增强了植株对营养元素的吸收。     

水分胁迫及VA菌根接种对绿豆生长的影响

本文采用土培试验研究了水分胁迫下接种VA菌根真菌Glomusmosseae,G .sp .和G .caledonium对绿豆生长及代谢活动的影响。结果表明 ,水分胁迫严重抑制了植株的生长 ,但对VA菌根真菌的侵染能力影响不大。接种VA菌根真菌不仅有利于植株对土壤中磷和氮的吸收 ,而且明显改善了植株的水分状况 ,降低了植株叶片的脯氨酸含量 ,提高了接种株叶片的光合效率 ,显著增加了植株干物质量 ,增强了绿豆的抗旱性或耐旱性。 3种真菌中 ,以Glomusmosseae的接种效果最好。     

丛枝菌根真菌与根瘤菌接种对大豆根瘤分布及磷素吸收的影响

在温室条件下,采用石英砂盆栽试验研究了大豆(冀豆6号)接种丛枝菌根真菌（Glomous mosseae）与根瘤菌 （Bradyrhizobium japonicum）对根瘤的形成、分布以及磷素吸收效率的影响。结果表明,大豆生长至开花期（接种后56 d）,与单接种根瘤菌处理相比,双接种AM真菌和根瘤菌显著增加大豆生物量、氮、磷含量、根系上的总根瘤数。单接种根瘤菌条件下,总根瘤数的48.4%分布在主根上,51.6%分布在侧根上;根瘤菌与AM真菌双接种时,总根瘤数的32.5%分布在主根上,67.5%分布在侧根上。双接种处理的侧根根瘤的固氮酶活性显著高于单接种处理的。双接种条件下大豆侧根中AMF侵染增强,尤其是结根瘤侧根上的AM真菌的侵染率高于未结瘤的侧根的菌根侵染率。接种后28 d单接种菌根真菌处理显著高于双接种处理的植株磷的吸收效率;而56 d 时趋势相反。以上结果表明,AM真菌侵染改变根瘤在大豆根系上的分布,根瘤数量、分布与结根瘤侧根上AM真菌的侵染强度存在正相关关系。     

丛枝菌根真菌对青稞生长发育及磷营养的影响研究

青稞是大麦类作物中的一种，是西藏地区栽培面积最大、产量最多、分布最广的农作物品种。近年来，青稞的保健作用（富含-β葡聚糖和“生育三烯酚”）已得到国内外公认，因而青稞生产受到更广泛的关注。然而，根据西藏首次土壤资源调查结果，全自治区低磷（速效磷〈10mgkg^-1）土壤占总耕地面积的46．9％～72．3％（内部资料）。土壤供磷不足是限制青稞高产的重要潜在因素之一，同时西藏目前没有一家化肥厂，生产、科研所需肥料全靠从内地长途运输。寻找一条经济有效的途径缓解西藏地区农业生产肥料紧缺的状况成为一项迫切的任务。     

菌根真菌对茶树吸收磷、钾素的影响

以辐照灭菌的酸性黄壤为供试土，种植有性繁殖的茶苗并接种ＶＡ菌根真菌，以不接种菌根真菌为对照，分别追施３２Ｐ－过磷酸钙和＾８６Ｒｂ－氯化铷，试验结果表明：菌根侵染率，＾３２Ｐ组合合为５２．６０％，＾８６Ｒｂ组合为５６．７０％，茶树株高分别对照的２．１０倍和２．５０倍，对磷、钾元素的吸收量分别比对照增加４．６０和３．１０倍，磷肥利用率提高１４．１０％，钾肥利用率提高１７．１３％。     

PHOSPHORUS NUTRITION AND MYCORRHIZAL GROWTH RESPONSE OF BROADLEAF AND NARROWLEAF BIRDSFOOT TREFOILS

In Argentina narrowleaf trefoil (Lotus glaber) predominates over broadleaf trefoil (Lotus corniculatus). Researchers have suggested this predominance occurs because L. glaber grows better at low levels of P availability. I studied the effect of increasing phosphorus (P) nutrition and mycorrhizal growth response of Lotus corniculatus and Lotus glaber in a soil of low available P. L. corniculatus was more efficient in P utilization than L. glaber and produced larger yields of shoot tissue per unit of P. The critical P concentration, measured as a percentage of P in the shoot required to achieve 90% of maximum shoot yield, was 0.22 in L. corniculatus and 0.28 in L. glaber. The roots of both two species were heavily infected by arbuscular micorrhizae (AM), and both mycorrhizal and nonmycorrhizal plants responded strongly to added P in soil. This suggests that both species are at no advantage or disadvantage whether mycorrhizal or nonmicorrhizal. The fraction of roots colonized by AM fungi differed between species at low levels of added P but was similar at high levels of added P. The specific root length (cm g^?1) of mycorrhizal plants was greatest in L. corniculatus when P was insufficient to achieve maximum growth. The lower critical P concentration and the higher specific root length at low levels of P nutrition may be why L. corniculatus is superior to L. glaber in soils low in P. Therefore, the predominance of L. glaber compared with L. corniculatus in Argentinean soils is not due to ability of L. glaber to grow better in soil at low levels of P availability.     

PHOSPHORUS EFFECTS IN THE NUTRITION AND GROWTH OF DEVELOPING MANGO PLANTS

The objective was to study the effects of phosphorous (P) fertilization on nutritional and developmental aspects of growing mango plants. The mango plants were evaluated by soil chemical analyses, leaf chemical analyses, biological examination of plant growth, and the starting point of fruit production. Having this in view, an experiment was set up on 2 January 2003, at Flora, a farm in Uberlandia, state of Minas Gerais, Brazil. The soil was a clayish Oxisol. The doses at planting were: D₀ = zero, D₁ = 40, D₂ = 100, D₃ = 200, and D₄ = 300 g of P₂O₅ plant^?1. These doses at the beginning of the second year were multiplied by 1.5 and at the beginning of the third year by 2.0 and applied to the plants. The fertilizer used in this experiment was triple superphosphate (44% of P₂O_5.). During August of 2004, 2005, and 2006, soil samples were taken at a depth of 20 cm in between the plant rows. Leaf samples were taken during August of 2004 and 2005 to determine macro- and micronutrient contents in the leaves. Plant stem diameter was measured during January of 2004 and 2005. Plant height and crown radius were measured during January of 2005 and fruit production in 2005 and 2006. Fertilizer applications increased the level of P in the soil but significantly influenced plant performance only after the second year. The effects of phosphorus on mango plants take place slowly leading to increments in plant stem diameter only at the third year. Fruit set was not influenced by phosphorous fertilization.     

EFFECT OF VESICULAR-ARBUSCULAR MYCORRHIZAL FUNGI ON THE RELATIONS OF PLANT GROWTH, INTERNAL PHOSPHORUS CONCENTRATION AND SOIL PHOSPHATE ANALYSES

The effect of infection by vesicular-arbuscular mycorrhiza on the predictive value of soil analysis for available P was tested in a glasshouse experiment. Leeks (Allium porrum) were grown on ten Rothamsted soils with a wide range of initial NaHCO₃-soluble P, each of which also received 5 levels of added P. Soils were partially sterilized with 1 Mrad of γ-radiation, or left untreated; plants on sterilized soil were infected with yellow-vacuolate endophyte (Glomus mosseae) or left non-mycorrhizal. The NaHCO₃-soluble P in the soils was measured 5 days after phosphate addition. Yields from all P levels on all soils were plotted against soil NaHCO₃-soluble P content and separate smooth response curves were obtained for non-infected and artificially-infected plants. Infection increased yield only on soils with less than 100 mg P kg^?1. In contrast, naturally-infected plants gave no clearly defined response curve to P, and on three soils the yields were consistently low. These soils gave very low natural infections and had low spore densities probably due to the cropping history of the sites. Artificially-infected plants had much higher shoot P concentrations than did uninfected plants of similar dry weight, over a large range of soil phosphate levels; this effect was also noted with the endophyte G. fasciculatus. Naturally-infected plants showed a poor relationship between shoot P concentration and yield.     

桂林柑桔基地土壤中微量元素状况与施用微肥效应

桂林地区是我国重点新兴柑桔基地之一.通过本研究证实桂林柑桔基地分布着大面积的贫锌、含硼、钼低的土壤类型,包括:古洪积物、砂页岩、河积物、石灰岩坡积物发育的土壤,初步估计仅缺锌面积达20万亩.合理施用微量元素肥料(锌、钼、硼),一般使柑桔产量提高20%以上,果实全糖含量均有所提高(4.4-17.2%),柠檬酸略有下降或保持不变.喷施锌肥果皮变薄,可食部分增加.喷施钼肥提高果实内维生素C的含量4.70-8.40mg/100ml果汁,柑桔成熟期提早7-10天,果皮着色鲜艳.土壤有效态Mo,Zn,Co,K,Ca和Mg等元素与柑桔叶片中相应的该元素之间均呈正相关,经统计达到显著或极显著水准.因而通过叶片的分析,可以有效的估量土壤中某些营养元素的丰缺状况,为合理地科学施肥提供依据.     

EFFECTS OF SALINITY AND CALCIUM ON THE GROWTH AND CHEMICAL COMPOSITION OF PISTACHIO SEEDLINGS

Poor quality of irrigation water (high salinity) has reduced the yields of pistachio over recent years, especially in Kerman. The effects of four salinity levels [0, 30, 60, and 90 mM sodium chloride (NaCl)] and three calcium (Ca) levels [0, 0.5, and 1 mM Ca as calcium nitrate (Ca(NO₃)₂.4H₂O)] on growth and chemical composition of pistachio seedlings cv. ‘Badami’ were studied in sand culture under greenhouse conditions in completely randomized design (CRD) with four replications. After 170 days, leaf area, leaf number, shoot and root dry weights were determined. Also shoot and root sodium (Na), potassium (K), Ca, and magnesium (Mg) concentrations were measured. Results showed salinity decreased all growth parameters. Ca application increased shoot and root Ca concentrations and root K concentration, while Ca application decreased shoot K concentration and shoot and root Mg concentrations. Salinity decreased shoot Ca, root K, and root Mg concentrations, while salinity increased shoot and root total sodium uptake, and shoot and root Cl concentrations.     

干旱对玉米幼苗吸收磷素的影响

本文研究了玉米幼苗在干旱处理下~(32)P的吸收,以及油菜素内酯(BR)和钙浸种对磷素营养的生理效应。结果表明,玉米幼苗根系对磷的吸收和向叶部转移量随干旱强度增大而减少;油菜素内酯和钙有增加根系吸收表面积 提高叶片相对含水量和根中ATP含量、促进磷的吸收和转移及缓解干早的作用