Establishment of Retama sphaerocarpa L. seedlings on a degraded semiarid soil as influenced by mycorrhizal inoculation and sewage‐sludge amendment

A field experiment was carried out to evaluate the effectiveness of mycorrhizal inoculation with three arbuscular mycorrhizal (AM) fungi (Glomus intraradices Schenck & Smith, Glomus deserticola (Trappe, Bloss. & Menge), and Glomus mosseae (Nicol & Gerd.) Gerd. & Trappe) and the addition of composted sewage sludge (SS) with respect to the establishment of Retama sphaerocarpa L. seedlings, in a semiarid Mediterranean area. Associated changes in soil chemical (nutrient content and labile carbon fractions), biochemical (enzyme activities), and physical (aggregate stability) parameters were observed. Six months after planting, both the addition of composted SS and the mycorrhizal‐inoculation treatments had increased total N content, available‐P content, and aggregate stability of the soil. Values of water‐soluble C and water‐soluble carbohydrates were increased only in the mycorrhizal‐inoculation treatments. Rhizosphere soil from the mycorrhizal‐inoculation treatments had significantly higher enzyme activities (dehydrogenase, protease‐BAA, acid phosphatase, and β‐glucosidase) than the control soil. In the short‐term, mycorrhizal inoculation with AM fungi was the most effective treatment for enhancement of shoot biomass, particularly with G. mosseae (about 146% higher with respect to control plants). The addition of the composted SS alone was sufficient to restore soil structural stability but was not effective with respect to improving the performance of R. sphaerocarpa plants.     

丛枝菌根真菌对镉胁迫水稻秧苗生长发育的影响

【目的】探讨丛枝菌根真菌（Arbuscular mycorrhizal fungi,AMF）对镉胁迫水稻秧苗生长发育的影响,为利用AMF菌根技术减少稻米镉超标提供理论指导。【方法】分别在无镉胁迫和1 mg/kg镉胁迫的水稻育秧土壤中接种摩西斗管囊霉（Funneliformis mosseae,FM）和根内根孢囊霉（Rhizophagus irregularis,RI）,以接种等量高温高压灭菌后的FM+RI菌剂为对照,30 d时测定这2种AMF对水稻秧苗根系的侵染率,并分析其对秧苗株高、生物量、叶绿素含量以及镉含量的影响。【结果】在无镉胁迫的条件下,FM、RI对水稻秧苗根系的侵染率分别为33.4%和24.9%;与对照相比,FM和RI处理秧苗的株高分别增加8.6%和7.6%（P<0.05）,生物量和叶绿素含量无显著性差异。在1 mg/kg镉胁迫的条件下,FM、RI对根系的侵染率分别为25.1%和20.3%;与对照相比,FM和RI处理秧苗的株高分别增加26.5%和21.0%（P<0.05）,生物量分别增加33.1%和18.6%（P<0.05）,叶绿素含量分别增加16.1%和15.2%（P<0.05）,根系镉含量分别增加186.2%和207.7%（P<0.05）,地上部分镉含量分别减少40.2%和36.8%（P<0.05）,镉转运系数均降低80.0%（P<0.05）。【结论】FM和RI能够显著促进镉胁迫水稻秧苗的生长发育,增强根系对镉的固定能力,减少镉从地下部分到地上部分的转运。     

Arbuscular mycorrhizae in a long-term field trial comparing low-input (organic, biological) and high-input (conventional) farming systems in a crop rotation

 Arbuscular mycorrhizal (AM) root colonization was studied in a long-term field trial in which four farming systems currently in use in Switzerland were continuously applied to a randomized set of plots at a single field site from 1978 till 1993. There were two low-input farming systems (organic and bio-dynamic) and two high-input (conventional) farming systems (according to Swiss guidelines of integrated plant production with and without farmyard manure). The systems had an identical 7-year crop rotation and tillage scheme and differed essentially only in the amount and type of fertilizer supplied and in plant protection management. The percentage of root colonization by AM fungi was determined in field samples 2–3 times over the growing season in crops in the rotation, namely in winter wheat (Triticum aestivum L. cv. Sardona), vetch-rye and grass-clover. We found the percentage of root length colonized by AM fungi to be 30–60% higher (P≤0.05) in the plants grown in soils from the low-input farming systems than in those grown in conventionally farmed soils. Approximately 50% of the variation of AM root colonization was explained by chemical properties of the soils (pH, soluble P and K, exchangeable Mg), the effect of soluble soil P being most pronounced. The potential of the field soils from the differently managed plots to cause symbiosis with AM fungi was tested in a glasshouse experiment, using wheat as a host plant. Soils from the low-input farming systems had a greatly enhanced capacity to initiate AM symbiosis. The relative differences in this capacity remained similar when propagules of the AM fungus Glomus mosseae were experimentally added to the soils, although overall root colonization by AM fungi was 2.8 times higher. Received: 27 August 1999     

AM真菌与根瘤菌对紫花苜蓿镰刀菌萎蔫和根腐病的影响

通过温室盆栽试验,探究了丛枝菌根(arbuscular mycorrhizal,AM)真菌摩西管柄囊霉与苜蓿中华根瘤菌对紫花苜蓿尖孢镰刀菌萎蔫和根腐病的影响,以期为合理利用两类共生菌,提高苜蓿抗病性提供理论依据。试验共8个处理,分别为接种或不接种AM真菌、根瘤菌和病原菌以及两两组合。与对照相比,AM真菌降低紫花苜蓿萎蔫和根腐病发病率80.13%(P<0.05)。AM真菌和根瘤菌互作促进苜蓿养分吸收、叶绿素合成,互作处理较对照叶绿素含量(soil and plant analyzer development value,SPAD值)提高61.85%,茎叶N含量提高26.5倍、P含量提高54.3倍,紫花苜蓿茎叶干重提高23.4倍(P<0.05)。AM真菌促进了紫花苜蓿根瘤的形成,较对照根瘤数多111.73%;AM真菌与根瘤菌二者互作,进一步促进了紫花苜蓿生长、养分吸收,降低了紫花苜蓿发病率,同时显著影响紫花苜蓿根系相关生化指标。互作处理提高超氧化物歧化酶(superoxide dismutase,SOD)活性41.05%,β-1,3-葡聚糖酶(β-1,3-glucanase)活性33.9%,茉莉酸(jasmonic acid,JA)浓度23.32%,木质素(lignin)16.92%,脱落酸(abscisic acid,ABA)、一氧化氮(nitric oxide,NO)和过氧化氢(hydrogen peroxide,H 2O 2)浓度分别降低26.68%,9.63%和25.26%,丙二醛(malondialdehyde,MDA)含量降低24.57%。综上所述,摩西管柄囊霉与苜蓿中华根瘤菌互作,可有效减轻紫花苜蓿镰刀菌萎蔫和根腐病的发生,二者具有良好的生防潜力。     

Mycorrhizal inoculation enhances growth and nutrition of cotton plant

Arbuscular Mycorrhizae Fungi (AMF) inoculations may improve growth and nutrient uptake of cotton (Gossypium hirsutum L.) plant. Although the importance of mycorrhizal symbioses for growth and nutrient acquisition of cotton plant is known, less is known about mycorrhizal dependency on P and Zn nutrition under low Zn fertile soil conditions. A greenhouse experiment was conducted to investigate the effect of different of P and Zn fertilizer addition on cotton plant growth as well as Zn and P uptake. Sterilized and non-sterilized low Zn fertile Konya series soil was treated with different levels of P and Zn. Soils were inoculated with two mycorrhizae species like Funneliformis mosseae and Claroideoglomus etunicatum after sterilization. Results showed that mycorrhizal inoculation on plant growth and nutrient uptake has significant effect when soil was sterilized. Cl. etunicatum mycorrhizae species has greater effect than Fu. mosseae mycorrhizae species. Root colonization increased 23–65% due to mycorrhizal amendment. The shoot: root ratio increased by 13 and 22% for non-sterile and sterile condition respectively in mycorrhiza amended soil. Mycorrhizal dependency varies 1–55% and 3–64% for non-sterile and sterile soil respectively on mycorrhizae, P and Zn amended soil. Mycorrhizal dependency analysis showed that cotton plant in both sterile and non-sterile soil conditions depends on mycorrhizae species, P nutrition, however is less depend on Zn nutrition. This study concluded that the inoculation of cotton plant with selected mycorrhizae is necessary under both sterile and non-sterile soil conditions.     

黄芪幼苗丛枝菌根形成过程研究

盆栽灭菌条件下,研究了黄芪Astragalus membranaceus与摩西球囊霉Glomus mosseae形成丛枝菌根的过程及细胞结构变化情况。结果发现,黄芪接种34 d时,真菌菌丝开始侵染根表皮;44 d时菌丝在皮层细胞内逐渐增多,并且细胞间有极少量泡囊产生,形状为椭圆形;54 d时细胞内大量菌丝扩展;63 d时有大量真菌孢子萌发;84 d时细胞间有大量泡囊形成,呈圆形、近圆形或椭圆形,部分泡囊开始收缩衰老,同时皮层细胞内有少量丛枝并存。生长期间,菌根侵染率和孢子密度的变化与丛枝菌根的发育状况密切相关。     

盐水胁迫下接种AM真菌对牡丹幼苗抗氧化酶活性的影响

将牡丹（Paeonia suffruticosa）幼苗接种丛枝菌根（arbuscular mycorrhizas,AM）真菌摩西球囊霉（Glomus mosseae）和地表球囊霉（G. versiforme）后,在4个不同盐水处理（质量百分比0、8%、16%和24%）下,研究AM真菌对牡丹抗氧化酶活性的影响。研究结果表明,8%盐水处理,牡丹幼苗菌根依赖性最高,且接种G. mosseae的处理显著高于接种G. versiforme的处理,分别为172%和150%;该胁迫30 d时,接种G. mosseae和G. versiforme植株干质量分别为0.51和0.45 g,叶片相对含水量分别为80.5%和78.5%,叶片超氧化物歧化酶（SOD）的活性分别为4.72 和4.46 U • g-1,过氧化物酶（POD）活性分别为60.3和57.4 U • min-1 • g-1,过氧化氢酶（CAT）活性分别为51.3和47.2 U • min-1 • g-1,均显著高于对照。16%和24%盐水处理下的表现与此相似。随盐胁迫时间的延长,SOD和CAT活性呈先升高后降低趋势,POD活性呈持续上升趋势。AM真菌通过增强牡丹幼苗抗氧化酶活性,提高其耐盐性,以G. mosseae接种效果较好。     

丛枝菌根真菌与胡萝卜毛状根双重培养体系研究

以发根农杆菌（Agrobacterium rhizogenes）K599诱导胡萝卜产生毛状根,接种丛枝菌根（AM）真菌摩西斗管囊霉（Funneliformis mosseae）建立双重培养体系,研究不同消毒方法、超声波、低温预处理和培养基pH对摩西斗管囊霉孢子萌发的影响及其与胡萝卜毛状根建立双重培养体系的最佳条件。研究结果表明：消毒方法3孢子萌发率最高,孢子污染率最低,15 d孢子萌发率达48.88%,而污染率仅为9.98%;超声波处理能降低孢子污染率11.17%~14.53%;低温预处理可有效提高孢子的萌发率,4℃低温处理10 d和15 d效果较好,其萌发率分别为70%和65%;AM真菌孢子在水琼脂培养基萌发最佳pH为6.5,萌发率达到48.50%,pH< 5.5或pH>8.0均抑制孢子萌发,pH 5.5和pH 8.0的萌发率分别为15.43%和16.06%。消毒孢子先于水琼脂萌发后,再挑取萌发管多,菌丝较长的孢子并将菌丝生长方向正对毛状根方向进行转接,可以提高双重培养的成功率。MSR培养基为双重培养的最优培养基。胡萝卜毛状根与AM真菌双重培养可为菌根真菌繁殖及相关分子机理研究提供可行有效的途径。     

Characterization of expressed genes in the establishment of arbuscular mycorrhiza between Amorpha fruticosa and Glomus mosseae

Arbuscular mycorrhiza （AM） formed between plant roots and fungi is one of the most widespread symbiotic associations in nature. To understand the molecular mechanisms of AM formation, we profiled 30 symbiosis-related genes expressed in Amorpha fruticosa roots colonized by Glomus mosseae and in non-mycorrhizal roots at different stages using differential-display RT-PCR （DDRT-PCR）. The expressed genes were confirmed by reverse Northern blotting. Eleven fragments were sequenced and putatively identified by homologous alignment. Of the eleven AM-related genes, five were obtained at the early-stage of plant-fungus interaction and six at the later stage. Three expressed se-quence tag （ESTs） sequences were found to originate from the fungi and eight from the host plant by use of PCR evaluation of gDNA of both plant and fungi. The target genes included an ATP-binding cassette sub-family transporter gene, a transposon-insertion display band, and a photosynthesis-related gene. The results provided information on the molecular mechanisms underlying the development of mycorrhizal sym-biosis between woody plants and AM fungi.     

接种摩西管柄囊霉(Funneliformis mosseae)对连作大豆根腐病病原菌菌群结构的影响

笔者将生物修复方法应用于连作大豆根腐病防治中,旨在降低连作大豆根腐病发生以及提高大豆质量。试验选择3个大豆品种作为试验材料并接种摩西管柄囊霉(Funneliformis mosseae),通过PCRDGGE技术研究F.mosseae对连作大豆根系以及根际土壤根腐病病原菌菌群结构的影响。试验结果表明:3个大豆品种接种F.mosseae后,试验组根样以及根际土样根腐病病原菌丰度以及多样性指数显著低于对照组,并且接种F.mosseae对不同大豆品种防治效果存在差异;聚类分析结果也验证了接种F.mosseae对连作大豆根样以及根际土样根腐病病原菌产生以及分布产生影响。