丛枝菌根真菌与大田辣椒定殖共生研究

以贵州省贵阳市3个辣椒种植地块的辣椒植株及根围土壤为试材,采用优化的湿筛倾注-蔗糖离心法从辣椒根围土壤中分离丛枝菌根真菌(AMF)孢子并测算根围中AMF孢子密度,乳酸甘油染色法对辣椒根样染色,观察辣椒根组织中AMF定殖情况,根据侵染分级强度法统计AMF的侵染率、侵染强度和丛枝丰度,对自然条件下辣椒根组织和根围中AMF的定殖共生进行了初步调查,以期为进一步研究AMF在辣椒大田种植生产中的作用提供依据和参考。结果表明:不同采样点的辣椒根组织中均发现AMF定殖及典型的共生丛枝菌根结构,侵染率达到70%以上;同时,在辣椒根际土壤中,存在丰富的AMF孢子,平均达到6个·g~(-1)土壤。不同采样点辣椒的AMF侵染率、侵染强度和根际孢子量等存在差异,并随着AMF侵染强度的增强,丛枝丰度和孢子密度也随之增加。上述结果表明,在自然条件下,大田辣椒根际土壤中存在丰富的AMF,并且AMF能够在辣椒根组织中定殖共生。     

紫花苜蓿根际丛枝菌根真菌与土壤理化性质的相关性研究

为调查山西省大同矿区紫花苜蓿草地中丛枝菌根真菌(AMF)与根际土壤性质之间的相关性,于2014年10月采集浑源县、南郊区、大同县、矿区4块样地中不同深度的紫花苜蓿根茎和根际土壤,并分析了紫花苜蓿的菌根侵染率以及土壤的理化性质。结果表明:4块样地中紫花苜蓿根部菌根侵染率均在70%以上;除大同县规律不明显以外,其它3块样地中菌根侵染率与孢子密度均表现出随着土层深度增加而降低的规律。分析总相关性得知,菌根侵染率与有机质、硝态氮、速效磷、易提取球囊霉素(EEG)和总球囊霉素(TEG)呈显著正相关性(P0.05);TEG和EEG均与菌根侵染率、有机质、硝态氮和速效磷呈极显著正相关(P0.01)。分析同土层各因素的相关性则发现,只有在20~30cm土层,菌根侵染率和孢子密度与硝态氮、速效磷、速效钾和EEG有显著相关性(P0.05)。以上结果说明,大同地区丛枝菌根真菌与紫花苜蓿可以形成良好的共生关系,菌根真菌对土壤营养成分具有重要的作用,尤其在20~30cm土层更有效。     

丛枝菌根真菌对番茄生长、根际酶活和微生物数量的影响

以番茄品种苏粉11号为材料,通过在有机基质中添加丛枝菌根真菌(AMF),研究AMF对番茄幼苗生长、侵染率、微生物数量和根际酶活的影响。结果表明,AMF显著提高了番茄幼苗的株高、茎粗、干质量、鲜质量和菌根侵染率,同时增加了幼苗根际细菌和放线菌数量,降低真菌数量,并提高蔗糖酶、中性磷酸酶、过氧化氢酶和脲酶的活性。说明添加AMF能够有效地提高根际微生物多样性,维持植株根际生态系统的稳定性,从而促进番茄植株的生长。     

根腐病对枳砧纽荷尔脐橙菌根生长的影响

在湖北省兴山县峡口镇,选取根腐病发生程度为重度(植株基本死亡,叶片和枝条干枯脱落)、轻度(叶片开始发黄,根开始腐烂且根表皮已断裂)以及未感病(树体正常)的9年生枳砧纽荷尔脐橙植株,取样分析菌根侵染率、根系活力、根际土壤孢子密度、根际土壤菌丝长度及根际球囊霉素相关土壤蛋白含量。结果表明,与未感病植株相比,轻度感病与重度感病植株根系菌根侵染率分别降低了50.4%和64.9%。根腐病的发生还显著抑制了根系活力、根际孢子密度和土壤菌丝长度,且抑制强度随着根腐病发生程度的加剧而增强。根腐病的发生也降低了球囊霉素相关土壤蛋白含量,尤其是难提取和总球囊霉素相关土壤蛋白。根腐病的发生抑制了菌根的生长以及菌根代谢物球囊霉素的释放。     

大青山不同坡位柄扁桃根围土壤丛枝菌根真菌(AMF)群落结构

以大青山阳坡柄扁桃幼根及根围土壤为试材,采用Phillips和Hayman的染色、湿筛倾析-蔗糖离心及土壤理化因子常规测定方法,研究了不同坡位柄扁桃根围土壤丛枝菌根真菌(AMF)群落结构及其土壤理化因子,以期了解土壤理化因子对柄扁桃根围土壤AMF群落结构的影响。结果表明:不同坡位柄扁桃菌根侵染率在一定范围内随着海拔的升高呈先升高后降低的现象。在不同坡位柄扁桃根围土壤中共分离出12属33种AMF,其中Funneliformis mosseae和Rhizophagus intraradices属于优势种。下坡位和中坡位AMF的孢子密度显著高于上坡位(P0.05)。下坡位种的丰度和Shannon-Weiner指数均显著高于中坡位和上坡位(P0.05)。AMF多样性主要受土壤理化因子全磷、pH、速效钾、速效磷的影响。     

矿区植物与丛枝菌根真菌共生效应

采用野外调查与室内分析相结合的方法,对邯郸武安煤矿区植物进行了菌根共生效应的研究,分析了20个科41种主要植物根系与丛枝菌根真菌(Arbuscular Mycorrhizae Fungi,AMF)的共生状况,筛选出该地区建群的优势植物,并探讨了不同科、植被间侵染率、侵染强度、孢子密度的关系。结果表明:18个科35种植物都能与丛枝菌根真菌形成共生关系,在不同科中,萝藦科、豆科、马鞭草科植物的侵染率较高;从植物种类上看,侵染率最高的是杠柳,其次是紫穗槐和牡荆,分别高达92.33%、85.30%和70.78%,不同植被类型中,乔木、灌木、草本类植被的菌根侵染率差异显著,从侵染强度上分析,不同植物间存在差异,但不显著;侵染率和孢子密度的关系因植物不同而异,二者没有严格的对应关系。     

采煤沉陷地丛枝菌根的应用及其生态效应研究

以陕西省大柳塔矿采煤沉陷地为试验地,自然状况下接种丛枝菌根真菌,研究了丛枝菌根对沙棘生长及根系发育的影响,并对接菌后根际微环境变化进行了探讨。结果表明:接菌处理植株地上和根系发育生长指标优于不接菌组。接菌后宿主植物与菌根能形成良好的共生关系,根际菌丝密度远高于对照。接种丛枝菌根增加了土壤微生物数量,提高了根际土壤磷酸酶活性,土壤速效养分含量也高于不接菌组。接种菌根对采煤沉陷地土壤具有一定的土壤改良效果,改善了土壤根际微生态环境,取得了较好的生态效益,对当地的生态修复具有重要意义。     

栽培蓝莓菌根侵染特性研究

为了解贵州省麻江县蓝莓基地菌根侵染情况,采用酸性品红染色法对麻江县3个蓝莓基地的兔眼蓝莓和龙崩基地不同品种的蓝莓进行菌根侵染情况调查,并对其根际土壤进行分析。结果表明,蓝莓菌根比较简单,主要有4种类型:丛枝菌根、杜鹃花类菌根、具柱状囊泡类型的菌根和外生菌根。各样地蓝莓菌根侵染情况不高;不同基地蓝莓菌根侵染率差异不明显;不同品种蓝莓菌根侵染率存在显著差异;15年生蓝莓菌根侵染率显著高于3~5年生蓝莓。蓝莓根系菌根侵染率与土壤P、SOC呈显著正相关、与全K、pH值呈显著负相关。     

丛枝菌根真菌菌剂扩繁及菌根化枸杞育苗技术研究

以"宁杞7号"枸杞为试材,以红三叶草和玉米2种宿主植物对4种丛枝菌根真菌(AMF)菌种进行了菌剂扩繁,采用枸杞嫩枝扦插育苗技术,利用自繁的AMF菌剂进行枸杞菌根化苗木繁育;苗木出圃后田间定植,调查田间的性状表现,以期为AMF在枸杞上的应用和深层研究提供了理论参考。结果表明:采用红三叶草和玉米2种植物作为宿主植物可以扩繁出高质量的丛枝菌根真菌菌剂,侵染率在94%以上,基质中孢子密度168~351个/50g干土;接种后育苗成活率均在60%以上,各处理间差异不大;接种处理的幼苗根系中均含有大量的真菌的菌丝体,菌根真菌的侵染率达43%以上;菌根化苗木的苗高生长明显高于对照,其中缩球囊霉、根内球囊霉和混合接种处理分别较对照提高了53.45%~89.66%,达极显著差异水平,摩西球囊霉接种处理较对照提高了39.66%,达显著差异水平;接菌处理的地径的生长量虽高于对照,但多重比较分析表明,不存在差异的显著性。     

丛枝菌根真菌在果树研究中的应用

正菌根(Mycorrhiza)是自然界中一种普遍存在的植物与真菌的共生现象,其中丛枝菌根真菌(Arbuscular mycorrhizal fungi,AMF)与植物形成的共生体最为广泛,约80%的陆生植物可形成丛枝菌根,是土壤中非常重要的一类功能微生物~([1])。AMF通过侵染进入植物根系皮层,在皮层细胞间形成菌丝,在皮层细胞内形成丛枝和泡囊结构。     

Effects of AMF inoculation on growth of Panax ginseng C.A. Meyer seedlings and on soil structures in mycorrhizosphere

We aimed to investigate the effects of inoculating Panax ginseng C.A. Meyer seedlings with arbuscular mycorrhizal fungi (AMF) by examining the root colonization, plant nutrition uptake, growth characteristics, and soil aggregation of P. ginseng seedlings inoculated at the time of transplantation. At 16 weeks, the AMF spore density per 30 g of fresh mycorrhizosphere in seedlings inoculated with AMF (AMF+ seedlings) was 256.8 and that in seedlings not inoculated with AMF (AMF− seedlings) was 186.3, respectively. The colonization rate of AMF in the lateral roots of AMF+ seedlings was approximately 19% higher than that in the lateral roots of AMF− seedlings. The patterns of AMF colonization in ginseng roots were similar to those of the Paris-type mycorrhizal association. Plant growth characteristics, such as plant height, root length, leaf area, number of lateral roots, fresh weight of shoots and roots, and chlorophyll content, were significantly enhanced in AMF+ seedlings compared to AMF− seedlings. The macronutrient content (P, K, and Ca) and micronutrient content (Cu, Fe, and Zn) of both shoots and roots were also significantly higher in AMF+ seedlings compared to AMF− seedlings. Furthermore, glomalin content and soil aggregation were significantly enhanced in AMF inoculated areas. Our results indicate that AMF inoculation may enhance the growth of ginseng seedlings by improving the uptake of mineral nutrients and the soil structure in mycorrhizosphere.     

Effects of pavements on diversity and activity of mycorrhizal symbionts associated with urban trees

This study investigated the impact of different types of soil sealing on the communities of a group of beneficial plant symbionts, arbuscular mycorrhizal fungi (AMF), colonizing the roots of two shade trees, Celtis australis and Fraxinus ornus, frequently grown in urbanized sites. Such plants were grown in an experimental site, in northern Italy, established in November 2011 and subjected to four different pavement treatments: impermeable monolithic asphalt, permeable pavers, permeable concrete and unpaved soil. The diversity and composition of root AMF communities were assessed by PCR denaturating gradient gel electrophoresis of partial 18S rRNA gene, AMF taxa were identified by amplicon sequencing and mycorrhizal colonization was evaluated after root clearing and staining. For the first time, our molecular work revealed that impermeable pavements induced shifts in the composition of AMF communities associated to the roots of C. australis and F. ornus and impacted on the percentage of mycorrhizal root length. When the root-zone was covered with permeable pavements, a similar AMF community as that observed in the unpaved soil was detected, providing novel information to be utilised for reducing the disturbance caused by specific types of soil sealing on AMF symbionts, which play a key role in plant nutrition and health. A total of 45 AMF sequence types were detected, with Sclerocystis and Septoglomus as the most abundant phylotypes, accounting for 84% of the sequences. The predominance of Sclerocystis species in the roots of both tree species under impermeable pavements indicated their high and unforeseen tolerance towards harsh environmental conditions. Such species could be utilized as AMF inocula specifically selected for their proven resilience in paved sites, in order to exploit their ability to boost biogeochemical processes fundamental for energy fluxes and plant nutrition and health.     

不同土壤管理方式对金柑VA菌根侵染率的影响

试验以15年生枳砧金弹(Fortunella crassifolia Swingle)和成年野生山金柑(F.hindsii Swingle)为试材,于1989～1991年在浙江宁波北仑、浙江普陀桃花岛进行。设置免耕生草覆草、耕翻生草覆草、清耕(对照)、野生(对照)等4个处理。结果表明。随耕翻次数增加,根系VA菌根侵染率降低,VA菌根侵染率野生>免耕生草覆草>耕翻生草覆草>清耕,20～40厘米土层>10～20厘米土层>0～10厘米土层。离根尖1厘米左右根段中泡囊出现百分率与VA菌根侵染率呈极显著或显著正相关。免耕可保护菌根,提高菌根侵染率。     

丛枝菌根真菌与土壤养分交互作用的生态效应研究

土壤养分影响AM真菌种属组成、AM真菌的丰度、孢子数量、孢子密度以及频度;AM真菌反过来影响宿主植物和土壤微生物及其群落多样性。在总结国内外相关研究成果基础上,分析了土壤养分N、P、K以及土壤有机质等因子对AMF生长发育及群落多样性的影响,不同AMF在不同土壤养分环境中对宿主植物的生长及N、P、K营养元素的吸收的影响,以及AMF对土壤微生物及其群落的影响。最后提出了AM真菌与土壤交互作用的几个重要方向,为今后开展菌根多样性及生物多样性研究提供依据。     

Selection of efficient arbuscular mycorrhizal fungi in the rhizosphere of cashew and their application in the cashew nursery

Mycorrhizal association in cashew (Anacardium occidentale L.) grown in five different plantation areas of South India was investigated. The soil samples were collected from all locations. Physico-chemical properties of rhizosphere soils, arbuscular mycorrhizal fungal spore count and root colonization were recorded. Species isolated were Acaulospora, Gigaspora, Glomus and Scutellospora. The mycorrhizal spore density was maximum at Thanjavur and minimum at Kudumiyamalai. Root colonization percentage oscillated between 20 and 30%. The species of Glomus, G. aggregatum Schenck and Smith, G. fasciculatum (Thaxter) Gerdemann and Trappe and G. mosseae (Nicol. and Gerd.) Gerdemann and Trappe were the most abundant in the majority of the experimental sites. Hence these three species were selected and used for artificial inoculation studies. Of the three mycorrhizal fungi G. fasciculatum significantly increased shoot length, internode number, internode length, number of leaves, stem diameter, root length and root number.     

Cultural Variation and Mycorrhizal Status of Blueberry Plants in NW Oregon Commercial Production Fields

ABSTRACT

Ericoid mycorrhizal fungi (EMF) form symbiotic relationships with roots of blueberry plants providing increased access to nutrients from fertilizers and soil. In August of 2001, we sampled 55 fields in Oregon to assess the mycorrhizal status of blueberry plants under production conditions and to determine whether any relationships exist between field characteristics, root distribution, soil characteristics and level of colonization by mycorrhizal fungi. Variation in measured soil characteristics, root type, root distribution and mycorrhizal colonization occurred with cultivar, field age, bed type, rate of nitrogen fertilization, irrigation type, and mulch. Root biomass was lower in the upper 15 cm of soil compared to 15-30 cm depth. Distribution of roots between the two sampled depths varied significantly with field age, nitrogen fertilization rate, and the time of 50% harvest for the different cultivars sampled. Root length was generally greatest in the upper 15 cm of the soil than at the 15-30 cm depth. Root colonization by ericoid mycorrhizal fungi (EMF) ranged from 0.5 to 44% of total root length with higher colonization generally occurring in the upper 15 cm of the soil where the majority of smaller, finer roots were found. Colonization generally increased with increasing plant age. In young plants the highest levels of colonization were found in roots from the upper 15 cm of soil while in older plants the highest levels of colonization were found in roots at the 15-30 cm depth. Colonization of roots by EMF in the upper 15 cm of the soil tended to decrease with increasing N fertilization rate, while root colonization at the 15-30 cm depth was unaffected by rate of N fertilization. Roots on cultivars that fruited early in the season tended to have higher levels of colonization than cultivars that fruited later in the growing season. Root biomass and root length were negatively correlated with soil pH and available Ca in soil, while root colonization by EMF was negatively correlated with ammonium levels in the soil. Differences in soil characteristics, root type and distribution, and mycorrhizal colonization found in this study need to be investigated in terms of production efficiency of blueberry in Oregon.     

Changes in free amino acid concentrations in mycorrhizal strawberry plants

The influence of arbuscular mycorrhizal fungi (AMF) colonization on free amino acid concentrations in strawberry (Fragaria × ananassa Duch., cv.Nohime) plants was investigated using two AMF species [Glomus mosseae (Gm), Gl. aggregatum (Ga)] under phosphorus-supplemented (+P) or non-supplemented (−P) conditions. Ten weeks after AMF inoculation, mycorrhizal plants showed higher values in dry weight of both shoots and roots than did non-mycorrhizal ones among most of the treatments. Shoots and roots of mycorrhizal plants had greater phosphorus concentrations in −P plots, while in +P plots, P concentrations differed little among the inoculation treatments. AMF colonization was greater in plants inoculated with Gm than in plants inoculated with Ga. Total amino acid concentration was higher in most of the plants inoculated with Gm than in non-mycorrhizal ones regardless of P treatment. Serine, glutamic acid, glycine, alanine, leucine and GABA were higher in both mycorrhizal plants in −P plots than in non-inoculated plants. In +P plots, threonine and isoleucine concentrations were greater in both mycorrhizal plants than in non-inoculated ones. Asparagine, glutamic acid, glycine, citrulline, GABA and arginine were greater in plants inoculated with Gm than in non-mycorrhizal ones. These findings verified that inoculation with AMF increases total amino acid concentrations and concentrations of specific amino acids in strawberry plants with or without phosphorus supplementation, though the effects varied with species of mycorrhizal fungus.     

丛枝菌根真菌对番茄苗期生长及矿质营养吸收的作用

以烘干粉碎后的秸秆与灭菌后的土壤配制成栽培基质,接种5种丛枝菌根菌种接种剂进行番茄栽培试验。结果表明,各种丛枝菌根共生微生物接种后对番茄幼苗生长发育和矿质元素吸收有很好的改善和促进作用,特别是对P、K吸收作用显著,对番茄干质量有明显增加作用。通过对番茄菌根侵染情况分析发现根部丛枝菌根侵染率(F)以Glomusmosseae-1和G.mosseae-2最高,可达30%以上,而丛枝菌根形成率(a)则以G.mosseae-2最高,促进番茄生长效果最好的菌种亦为G.mosseae-2。     

Effect of arbuscular mycorrhizal fungi on growth,mineral nutrition,antioxidant enzymes activity and fruit yield of tomato grown under salinity stress

The purpose of this study was to investigate the mechanisms underlying alleviation of salt stress by arbuscular mycorrhizal fungi Glomus mosseae. Tomato (Lycopersicon esculentum L. cv. Zhongzha105) plants were cultivated in soil with 0, 50 and 100 mM NaCl. Mycorrhization alleviated salt induced reduction of root colonization, growth, leaf area, chlorophyll content, fruit fresh weight and fruit yield. The concentrations of P and K were higher in AM compared with nonAM plants grown under nonsaline and saline conditions. Na concentration was lower in AM than nonAM plants grown under nonsaline and saline conditions. AMF colonization was accompanied by an enhancement of activity of superoxide dismutase (SOD), catalase (CAT), peroxidase (POD) and ascorbate peroxidase (APX) in leaves of both salt-affected and control plants. In addition, inoculation with AMF caused reduction in MDA content in comparison to salinized plants, indicating lower oxidative damage in the colonized plants.     

不同间作模式对设施黄瓜生长及土壤环境的影响

采用小麦、大豆、燕麦为伴生作物与黄瓜间作，研究其对黄瓜生长发育及土壤环境的影响。结果表明：3种间作处理均使土壤容重显著降低，土壤总孔隙度显著提高；整个生育期内各间作处理均显著降低了土壤盐分积累，生育后期黄瓜—小麦处理的土壤EC值下降幅度最大，比对照下降38.96 %；黄瓜—小麦和黄瓜—燕麦处理的土壤有机质含量显著高于对照；各间作处理明显改善了土壤微生物的区系组成，使细菌和放线菌数量增加，土传病菌数量降低，以黄瓜—小麦处理最明显，尖孢镰刀菌3个时期的平均数量比对照下降了69.44 %；各间作处理明显促进了黄瓜生长和产量的提高。黄瓜—小麦间作的综合效果最好，达到了缓解设施土壤连作障碍的目的。