Arbuscular Mycorrhizal Fungi Infection Research Articles

Effects of grassland degradation on diversity of arbuscular mycorrhizal fungi of a pioneer plant.

Arbuscular mycorrhizal fungi (AMF) are obligate symbionts that engage in crucial interactions with plants, playing a vital role in grassland ecology. Our study focuses on the pioneer plant Agropyron cristatum, and we collected soil samples from four degraded grasslands in Yudaokou to investigate the response of community composition to the succession of degraded grasslands. We measured the vegetation status, soil physical and chemical properties, AMF colonization, and spore density in different degraded grasslands. High-throughput sequencing was employed to analyze AMF in soil samples. Correlations among community composition, soil characteristics, and plant factors were studied using principal component and regression analyses. The distribution of AMF in grasslands exhibited variation with different degrees of degradation, with Glomus, Scutellospora, and Diversispora being the dominant genera. The abundance of dominant genera in AMF also varied, showing a gradual increase in the relative abundance of the genus Diversispora with higher degradation levels. AMF diversity decreased from 27.7% to 12.4% throughout the degradation process. Among 180 samples of Agropyron cristatum plants, AMF hyphae and vesicles displayed the highest infection status in non-degraded grasslands and the lowest in severely degraded ones. Peak AMF spore production occurred in August, with maximum values in the 0-10-cm soil layer, and the highest spore densities were found in lightly degraded grasslands. Apart from pH, soil factors exhibited a positive correlation with AMF infection during grassland degradation. Furthermore, changes in AMF community composition were jointly driven by vegetation and soil characteristics, with vegetation coverage and soil organic carbon significantly impacting AMF distribution. Significant differences in AMF variables (spore number and diversity index) were also observed at different soil depths. Grassland successional degradation significantly influences AMF community structure and composition. Our future focus will be on understanding response mechanisms and implementing improvement methods for AMF during grassland degradation and subsequent restoration efforts.

Integrated transcriptomic and metabolomic analyses reveal the effect of mycorrhizal colonization on trifoliate orange root hair

Trifoliate orange (Pocirus trifoliata) as an excellent stock for citrus, but it has few root hairs and relies on mycorrhiza (AM) formed by arbuscular mycorrhizal fungi (AMF) to absorb soil nutrients and water, and there are few studies on the relationship between trifoliate orange root hair and AMF. This experiment analyzed the conditioning of AMF in trifoliate orange root hair growth from multiple perspectives. The results showed that AMF inoculation promoted root hair in citrus (eg: density and length) and the AMF mycorrhizal infection rate was 49.12 %. Metabolic and transcriptomic data of root also show that AMF promotes the development of root hair mainly by influencing hormone transduction and biosynthesis. The analysis of hormone synthesis signal transduction expression profile showed that AMF infection significantly up-regulated auxin, gibberellin, ethylene and cytokinin synthesis and signal transduction pathway, and also up-regulated auxin transport and jasmonic acid transduction. Analysis of root hair growth-related genes showed that AMF infection the up-regulated genes correlate with cell wall loosening, Ca2+ gradient and cell cycle, thereby facilitate the formation and elongation of root hair. In summary, AMF regulates trifoliate orange root hair growth through plant hormone metabolism and related key genes, thus increases the root surface area and further promotes the infection of AMF. In order to provide theory foundation for exploring the mechanism of AMF regulating trifoliate orange root hair growth.

Plant compensatory growth: its mechanisms and implications to agricultural sustainability under global environmental changes

ABSTRACT Compensatory growth represents the ability of plants to counteract the negative consequences of herbivore damage, contributing to the sustainable development of agriculture. Minor changes in compensatory growth due to environmental changes may significantly impact the structure and functionality of ecosystems, especially for agriculture in a semiarid region. However, there is a lack of systematic quantitative summaries and reviews on compensatory growth mechanisms, especially regarding how they might respond to global environmental changes (e.g. climate warming, drought, nutrient variation, and elevated CO2). This paper summarizes the types of physio-ecological responses of plant compensatory growth to defoliation and their characteristics through a systematic review of existing literature. The review shows that damaged plants that undergo variations in morphological and physiological traits, such as enhanced photosynthesis, increased branching, and altered biomass allocation, may mitigate injury or produce overcompensatory growth. Moderate disturbance and arbuscular mycorrhizal fungus infection rates are beneficial for overcompensation. I further discuss how plant compensatory growth is affected by global change factors, concluding that adequate nutrients and water supply are crucial factors influencing overcompensation. This summary can advance our understanding of the response patterns and mechanisms underlying plant compensatory growth, which is vital for gaining insight into the regenerative capacity of plants and promoting sustainable agricultural development under global environmental changes.

The Effect of Pruning and Growing Media Composition on Arbuscular Mycorrhizal Propagation

The symbiosis of arbuscular mycorrhizal fungi with plants is the oldest symbiosis in the world. The obligate nature of mycorrhizal fungi in symbiotic relationships is believed to underlie its enduring presence to this day. The application of arbuscular mycorrhizal fungi (AMF) based fertilizers has become increasingly common. Spores are the most important organs that determine the quality of AMF-based fertilizers, along with AMF colonization in the roots. The production of AMF spores is greatly influenced by plant physiology, including photosynthesis processes affected by canopy abundance, as well as the type of planting medium, which determines plant root growth and AMF habitat. This study was conducted to investigate the effect of pruning and planting medium composition on AMF infection and spore production in AMF propagation using sorghum as the host plant. The pruning levels tested were at one, two, and three months after germination, and thereafter, each plant was maintained for 136 days after planting (DAP). The tested planting medium composition was the ratio between zeolite and compost in five different compositions: (v/v) 1) 100:0, 2) 90:10, 3) 70:30, and 4) 50:50. The chemical characteristic of compost used was contained 15.5% C, 1.49% N, 2.54% P2O5, 1.49% K2O, pH 6.6, and some microelements such as Cr, Fe, Zn, and Mn at 5.2 ppm, 5961 ppm, 294 ppm, and 199 ppm, respectively. The Sukabumi‘s zeolite used had a size of 2-3 mm. Propagation of AM fungal spores was carried out using polybags containing 10 kg of medium according to the treatment. Plant maintenance was carried out by alternating between watering with water and Johnson nutrient solution. Watering was performed until the plants were 120 days old, and subsequently, no watering was done until 136 days after planting. The observed parameters were the development of AMF spore numbers until a 4.5-month incubation period. The results showed that pruning time can affect spore production if the plant has reached a certain vegetative age, which is three months for sorghum. Additionally, adding 10% compost to zeolite medium can enhance spore formation, even though sorghum growth may not be at its maximum in this medium composition.

Plant and Soil Microbial Diversity Co-Regulate Ecosystem Multifunctionality during Desertification in a Temperate Grassland.

Biodiversity plays a crucial role in driving multiple ecosystem functions in temperate grasslands. However, our understanding of how biodiversity regulates the impacts of desertification processes on ecosystem multifunctionality (EMF) remains limited. In this study, we investigate plant diversity, soil microbial diversity (fungal, bacterial, archaeal, and arbuscular mycorrhizal fungal (AMF) diversity), soil properties (soil water content, pH, and soil clay content), and multiple ecosystem functions (soil N mineralization, soil phosphatase activity, AMF infection rate, microbial biomass, plant biomass, and soil C and nutrients (N, P, K, Ca, Fe, Na, Cu, Mg, and Mn)) at six different grassland desertification intensities. The random forest model was conducted to assess the importance of soil properties, plant diversity, and soil microbial diversity in driving EMF. Furthermore, a structural equation model (SEM) was employed to analyze the indirect and direct impacts of these predictors on EMF. Our study showed that plant, soil bacterial, fungal, and archaeal diversity gradually decreased with increasing desertification intensity. However, only AMF diversity was found to be less sensitive to desertification. Similarly, EMF also showed a significant decline with increasing desertification. Importantly, both plant and soil microbial diversity were positively associated with EMF during desertification processes. The random forest model and SEM revealed that both plant and soil microbial diversity were identified as important and direct predictors of EMF during desertification processes. This highlights the primary influence of above- and below-ground biodiversity in co-regulating the response of EMF to grassland desertification. These findings have important implications for planned ecosystem restoration and sustainable grassland management.

Effect of agricultural management practices on diversity, abundance, and infectivity of arbuscular mycorrhizal fungi: a review

Effect of agricultural management practices on diversity, abundance, and infectivity of arbuscular mycorrhizal fungi: a review

Effects of arbuscular mycorrhizal fungi inoculation on infection and growth of rice and pearl millet in upland fields with three water regimes

ABSTRACT Inoculation with arbuscular mycorrhizal fungi (AMF) may enhance crop growth in upland fields, depending on the water regime. To quantify changes in AMF infection rate and subsequent effects on nutrient uptake and growth, we grew rice (wetland crop) and pearl millet (dryland crop) genotypes with or without the commercial inoculant Dr. Kinkon (Glomus sp. R10) in Andosol upland fields in 2020 and 2021. Root infection rates were measured in shallow (0–10 cm) and deep (20–30 cm) layers under three water regimes: well-irrigated, half-irrigated, and non-irrigated. Inoculation enhanced shoot dry weight (SDW), plant height, tiller number, phosphorus (P) uptake, leaf water potential, photosynthetic rate (measured only in 2021) and root transversal area. The increase in SDW with inoculation was higher under well-irrigated than under water-limited conditions. The increment in pearl millet SDW was related to higher P uptake associated with higher infection rates, whereas that in rice SDW was related to maintenance of leaf water potential, greater root transversal area and root length density, and higher P uptake but not to infection rate parameters. Inoculation increased mycorrhizal and vesicular infection rates with the similar tendency for arbuscular infection rate and qPCR. Infection rates were similar across water regimes in both years despite significant differences in plant growth parameters with higher rates in deep than shallow layers. AMF inoculation enhanced infection rates, mostly independent of water regime, but plant growth enhancement was greater under the well-irrigated treatment and was more directly linked with infection rates in pearl millet.

Effects of Altitude and Continuous Cropping on Arbuscular Mycorrhizal Fungi Community in Siraitia grosvenorii Rhizosphere

Siraitia grosvenorii, a medicinal plant with continuous cropping, is cultivated in southern China. Changes in the soil microbial community during continuous cropping can cause soil-borne diseases in S. grosvenorii. This experimental study aimed to determine the differences in the arbuscular mycorrhizal fungi (AMF) community structure and root colonization in the rhizosphere soil of S. grosvenorii with different continuous cropping years and altitudes. We tested three altitude gradients (low, 200–300 m; middle, 500–600 m; and high, 700–800 m) and four continuous cropping years (1, 2, 3, and 5 years). AMF colonization, along with AMF spore density, and the soil physicochemical properties of S. grosvenorii roots at different altitudes and continuous cropping years were determined. Illumina high-throughput sequencing was used to determine the molecular diversity of AMF in the rhizosphere of S. grosvenorii as they exhibited a symbiotic relationship. The AMF species in the rhizosphere soil of S. grosvenorii included 28 species of nine genera, including Glomus, Claroideoglomus, Acaulospora, Paraglomus, Ambispora, and so on. With an increasing altitude, the AMF colonization of S. grosvenorii roots increased significantly (p < 0.01); available phosphorus (AP) content was negatively correlated with AMF colonization (p < 0.01). Glomus and Paraglomus were the common dominant genera in the rhizosphere soil of S. grosvenorii planted for 2–5 years at a low altitude and 1 year at middle and high altitudes. The average relative abundance of Glomus increased with increasing continuous cropping years and altitude in the low-altitude and 1-year S. grosvenorii areas, respectively. Slightly acidic rhizosphere soil contributed to AMF colonization and improved the richness and diversity of the AMF community. Our results showed that altitude, AP, and pH are essential factors for predicting AMF infection and community changes in the S. grosvenorii rhizosphere. Here, Illumina high-throughput sequencing was used to study the species resources and community composition of mycorrhizal fungi in S. grosvenorii in the hilly areas of Guangxi, China. This study provides a theoretical basis for the application and practice of mycorrhizal fungi including the isolation and screening of dominant strains, inoculation of mycorrhizal fungi, and exploration of the effects of mycorrhizal fungi on the growth and active ingredients of medicinal plants.

Impact of long-term application of paclobutrazol in communities of arbuscular mycorrhizal fungi and their efficiency in the development of Helianthus annuus L.

Paclobutrazol (PBZ) is a phytoregulator known for inhibiting plant vegetative growth and promoting flowering in mango crop (Mangifera indica L.). PBZ belongs to the triazole family, a group recognized by its fungicide capacity, and its application to the soil can directly influence microbial communities, however, little is known about its effects on arbuscular mycorrhizal fungi (AMF). The objectives of this work were to evaluate the impact of long-term application of PBZ on the AMF communities and to verify whether the management time affects the functionality of these communities in promoting the development of ornamental sunflower Helianthus annuus L. (var. Dwarf Double Sungold). Sampling was carried out in mango cultivation areas with a history of PBZ application that varied from no application to application for up to 15 years. For the analysis of the AMF community, the quantification of most probable number (MPN) of infective AMF propagules, abundance of glomerospores, richness, diversity, Simpson dominance, and Pielou's evenness were evaluated. The analysis of the functionality of the AMF community was based on the analysis of the variables of growth and mycorrhizal colonization. Soils with a prolonged history of PBZ application (>nine years) presented distinct AMF communities with lower abundance of glomerospores in relation to areas without PBZ application and with native Caatinga vegetation. However, the soil-inoculum of this AMF community has greater efficiency in promoting sunflower development and mycorrhizal colonization, suggesting greater functionality. It is concluded that the time of application and performance of PBZ in the soil influence the composition of the AMF community. Even with reduction of richness and diversity of AMF species in soils with a prolonged history of PBZ application, there are functional AMF communities in these soils that promoted sunflower plant growth, selecting more efficient and resistant species.

Effects of Rhizophagus intraradices and Acinetobacter calcoaceticus on Soybean Growth and Carbendazim Residue

In agricultural production, carbendazim and other pesticides are used to prevent soybean root rot. However, carbendazim degrades slowly and affects a series of biochemical processes such as soil biological nitrogen fixation and soil nutrient activation in the natural environment. This study mainly investigated the effects of Rhizophagus intraradices, Acinetobacter calcoaceticus, and carbendazim on soybean biomass, the incidence of root rot, the total number of bacterial colonies and phosphorus-solubilizing bacteria in rhizosphere soil, and carbendazim residue in soybean grains and rhizosphere soil. The results showed that the arbuscular mycorrhizal fungi (AMF) spore density, AMF infection rate, soybean biomass, nodule number, total bacterial colonies, and phosphorus-solubilizing bacteria colonies in the soybean rhizosphere soil were the highest in the R. intraradices and A. calcoaceticus treatment groups under natural soil conditions. Moreover, the incidence of root rot and carbendazim residue in soybean grains and rhizosphere soil were the lowest in the R. intraradices and A. calcoaceticus treatment group under natural soil conditions. This result indicated that R. intraradices and A. calcoaceticus can effectively reduce carbendazim residue in soybean grains and rhizosphere soil. This study provided theoretical support for the development of microbial fertilizer and microbial degradation of pesticide residues and improved the practical basis for ensuring food safety.

The Alien Invader, Rhus typhina L., Outperforms Its Native Competitor in the Scenario of Nitrogen Deposition and Arbuscular Mycorrhizal Fungi (AMF) Inoculation

Nitrogen deposition has been proven to facilitate the establishment of alien plants. Previous studies have certified that nitrogen deposition enhances the resource availability of habitats and promotes the growth of alien invaders. Arbuscular mycorrhizal fungi (AMF) symbiose with vascular plants and assist plants in nutrient acquisition. AMF colonization has been proven to be another driving factor of plant invasion. However, few studies have integrated nitrogen deposition and AMF inoculation into the exploration on invasion mechanism. Based on a trait approach, the present study subjected the alien invader, Rhus typhina L., and its co-occurring native species, Acer truncatum Bunge, to nitrogen deposition and AMF inoculation and compared the phenotypic variation in aboveground and belowground traits in an inter-specific competition experiment. Through the effects of different nitrogen deposition and AMF infection on the functional traits of R. typhina and A. truncatum, the effects of mycorrhizal symbiosis between R. typhina and A. truncatum on abiotic factors and interspecific relationships were analyzed. We found that inter-specific competition stimulated the colonization of AMF in R. typhina, however, decreased the colonization rate of AMF in A. truncatum. Correspondingly, inter-specific competition significantly reduced the plant growth of A. truncatum as the aboveground morphological traits including plant height and crown area, and belowground traits including root length, root surface area, root volume, number of root tips, number of root tip branches and number of root cross decreased for A. truncatum. Nitrogen deposition promoted the shoot growth of R. typhina rather than that of A. truncatum. AMF inoculation significantly affected the belowground traits of A. truncatum as the root length and root surface area significantly decreased after AMF inoculation in the mixture planting of the two species. The chlorophyll content of A. truncatum decreased without AMF inoculation, while nitrogen deposition enhanced the net photosynthetic rate of R. typhina. The alien invader R. typhina outperforms its native competitor in the simulated scenario of resource fluctuation and facilitates its establishment. We speculate that AMF colonization promotes the extension of R. typhina rhizosphere and, thus, accelerates the growth and invasion of R. typhina.

Trap Culture and Colonization of Arbuscular Mycorrhizal Fungi from Corn Roots in Tidal Swamps Using Several Host Plants

Arbuscular mycorrhizal fungi (AMF) are mycorrhizal from the endomycorrhizal group. The fungi live on higher plants' roots by performing symbiotic mutualism. This study aimed to identify AMF spores after trapping in corn roots and the degree of root infection by AMF in several host plants. The study was conducted using tidal swamps soil samples taken from Mulyasari Tanjung Lago Village, Banyuasin Regency, South Sumatra. The experiment used a randomized block design and three replicates with four host plants as a treatment: corn, soybean, sugarcane (monoculture) and sugarcane-soybean (combination). The results showed that AMF spores found on corn roots after trapping were from the <em>Acaulospora</em> sp. and <em>Glomus</em> sp. groups. Hyphae, vesicles, arbuscules and spores are AMF structures found in the roots of host plants infected by AMF. The percentage of AMF infection in host plant roots ranged from 1.11% to 77.44% where the highest was in maize host plant roots at 77.44% in the form of internal hyphae. The maize host plant has a high potential to be colonized by AMF compared to a mixture of soybean, sugarcane and sugarcane-soybean.

Drought Changes the Trade-Off Strategy of Root and Arbuscular Mycorrhizal Fungi Growth in a Subtropical Chinese Fir Plantation

As a consequence of changing global rainfall patterns, frequent extreme droughts will significantly affect plant growth and ecosystem functions. Fine roots and arbuscular mycorrhizal fungi (AMF) both facilitate Chinese fir nutrient uptake. However, how the growth of fine roots and AMF is regulated for the Chinese fir under drought conditions is unclear. This study used a precipitation reduction treatment (−50% throughfall) to study the seasonal effects of drought on a subtropical Chinese fir plantation. The effects measured included the fine root production, root diameter, specific root length, specific surface area, root tissue density, mycorrhizal hyphal density, spore number, mycorrhizal infection rate and total glomalin. Drought had no significant effect on Chinese fir fine root production but decreased the diameter and tissue density of primary and secondary roots while increasing the specific surface area of secondary roots. Additionally, drought significantly decreased the arbuscular mycorrhizal infection rate and significantly increased hyphal density. The results showed that drought caused the decrease in root diameter, which decreased the surface area available for AMF infection and led to the increase in mycorrhizal hyphal density. Redundancy analyses showed that soil-dissolved organic carbon and nitrogen were the key factors affecting AMF. Our results show that drought could enhance the cooperative strategy of nutrient and moisture absorption by roots and mycorrhizae of the Chinese fir, improving the resistance of Chinese fir growth to drought.

Arbuscular Mycorrhizal Fungi Alleviate Low Phosphorus Stress in Maize Genotypes with Contrasting Root Systems.

Soil available phosphorus (P) is one of the main factors limiting plant growth and yield. This study aimed to determine the role of arbuscular mycorrhizal fungi (AMF) in P-use efficiency in two maize genotypes with contrasting root systems in response to low P stress. Maize genotypes small-rooted Shengrui 999 and large-rooted Zhongke 11 were grown in rhizoboxes that were inoculated with or without AMF (Funneliformis mosseae) under low P (no added P) or optimal P (200 mg kg-1) for 53 days. Low P stress significantly inhibited shoot and root growth, photosynthesis, tissue P content, and root P concentration in both genotypes. Shengrui 999 was more tolerant to P stress with less reduction of these traits compared to Zhongke 11. Shengrui 999 had a higher AMF infection rate than Zhongke 11 at both P levels. Under P deficit, inoculation with AMF significantly promoted plant growth and P uptake in both genotypes with more profound effects seen in Zhongke 11, whilst Shengrui 999 was more dependent on AMF under optimal P. Low P stress inhibited the growth and physiological attributes of both genotypes. The small-rooted Shengrui 999 was more tolerant to low P than Zhongke 11. Inoculation with AMF alleviates low P stress in both genotypes with a more profound effect on Zhongke 11 at low P and on Shengrui 999 at high P conditions.

PENGARUH BERBAGAI JENIS MEDIA TANAM TERHADAP PERKEMBANGBIAKAN FUNGI MIKORIZA ARBUSKULA DENGAN MENGGUNAKAN TANAMAN INANG KACANG HIJAU (Vigna radiata L.)

This study was conducted to determine the effect of various types of growing media on the proliferation of arbuscular mycorrhizal fungi using mung bean host plants. This research was conducted at the Greenhouse, Faculty of Agriculture, Universitas Muslim Indonesia, and the Laboratory of Microbiology, Research, and Development Center for Environment and Forestry. The study started from April to August 2021. This study was compiled based on a completely randomized design consisting of four treatments of growing media, namely: soil, soil + raw husk, soil + husk charcoal, and soil + raw husk + husk charcoal. Each treatment was repeated 3 times so that 12 experimental units were obtained, and each experimental unit used 3 polybags so that there were 36 polybags in all. The results showed that the difference in planting media had an effect on the proliferation of arbuscular mycorrhizal fungi. Soil growing media obtained the highest arbuscular mycorrhizal fungal infection, namely 76.11%, and the number of spores, 49.33. The growth of the host plant (mung bean) was better in soil + husk charcoal as indicated by the number of leaves of 17 pieces, a root length of 37.66 cm, and a root volume of 2.33 ml.

The Indigenous Arbuscular Mycorrhizal Fungi Consortium in Shallot Cultivation with Lead-Polluted Media

This study aims to test a consortium of indigenous Arbuscular Mycorrhizal Fungi (AMF) in shallot cultivation with Pb contaminated media. The experiment was carried out in a greenhouse. A completely randomized design (CRD) was used in this study with one treatment factor. The treatment was the customary consortium of indigenous AMF from 17 locations of shallot land contaminated by Pb. The application of AMF showed no significant effect on fresh bulb fresh weight, leaf fresh weight, plant fresh weight, the total length of leaves, and the number of shallots. The percentage of infection in all treatments, except controls, showed a high percentage of AMF infection. AMF treatment from Slatri Land II showed the highest percentage of infection, that is 93.33%. The consortium of indigenous AMF from Kupu Land II was able to reduce the highest Pb accumulation of tubers compared to the control by up to 83.660%.

Combined Bioremediation of Bensulfuron-Methyl Contaminated Soils With Arbuscular Mycorrhizal Fungus and Hansschlegelia zhihuaiae S113.

Over the past decades, because of large-scale bensulfuron-methyl (BSM) application, environmental residues of BSM have massively increased, causing severe toxicity in rotation-sensitive crops. The removal of BSM from the environment has become essential. In this study, the combined bioremediation of the arbuscular mycorrhizal fungi (AMF) Rhizophagus intraradices and BSM-degrading strain Hansschlegelia zhihuaiae S113 of BSM-polluted soil was investigated. BSM degradation by S113 in the maize rhizosphere could better promote AMF infection in the roots of maize, achieving an infection rate of 86.70% on the 36th day in the AMF + S113 + BSM group. Similarly, AMF enhanced the colonization and survival of S113 in maize rhizosphere, contributing 4.65 × 105 cells/g soil on the 15th day and 3.78 × 104 cells/g soil on the 20th day to a population of colonized-S113 (based possibly on the strong root system established by promoting plant-growth AMF). Both S113 and AMF coexisted in rhizosphere soil. The BSM-degrading strain S113 could completely remove BSM at 3 mg/kg from the maize rhizosphere soil within 12 days. AMF also promoted the growth of maize seedlings. When planted in BSM-contaminated soil, maize roots had a fresh weight of 2.59 ± 0.26 g in group S113 + AMF, 2.54 ± 0.20 g in group S113 + AMF + BSM, 2.02 ± 0.16 g in group S113 + BSM, and 2.61 ± 0.25 g in the AMF group, all of which exceeded weights of the control group on the 36th day except for the S113 + BSM group. Additionally, high-throughput sequencing results indicated that simultaneous inoculation with AMF and strain S113 of BSM-polluted maize root-soil almost left the indigenous bacterial community diversity and richness in maize rhizosphere soil unaltered. This represents a major advantage of bioremediation approaches resulting from the existing vital interactions among local microorganisms and plants in the soil. These findings may provide theoretical guidance for utilizing novel joint-bioremediation technologies, and constitute an important contribution to environmental pollution bioremediation while simultaneously ensuring crop safety and yield.

不同水分处理下双接种丛枝菌根真菌和根瘤菌对疏叶骆驼刺生长及氮素转移的影响

PDF HTML阅读 XML下载 导出引用 引用提醒 不同水分处理下双接种丛枝菌根真菌和根瘤菌对疏叶骆驼刺生长及氮素转移的影响 DOI: 10.5846/stxb202105181301 作者: 作者单位: 作者简介: 通讯作者: 中图分类号: 基金项目: 国家自然科学基金项目（42067067）；新疆维吾尔自治区自然科学基金项目（2020D01A74） Effects of double inoculation with arbuscular mycorrhizal fungi and rhizobia under different water treatments on growth and nitrogen transfer of Alhagi sparsifolia Author: Affiliation: Fund Project: 摘要 | 图/表 | 访问统计 | 参考文献 | 相似文献 | 引证文献 | 资源附件 | 文章评论 摘要:以疏叶骆驼刺为研究对象，设定3个水分梯度正常水分（土壤相对含水量（70±5）%）、干旱胁迫（土壤相对含水量（20±5）%）和复水处理（干旱胁迫60天后恢复至正常水分）与四组接种处理（单接种丛枝菌根真菌（AMF）、单接种根瘤菌、双接种AMF+根瘤菌和不接种），分析不同水分条件下双接种丛枝菌根真菌和根瘤菌对疏叶骆驼刺的生长以及供、受体疏叶骆驼刺之间氮素转移的影响。结果表明，正常水分处理时，双接种疏叶骆驼刺的AMF侵染率、地上生物量、地下生物量、总生物量以及氮含量均要高于单接种处理；根瘤数量、最大荧光（Fm）、初始荧光（Fo）、最大光化学效率（Fv/Fm）与单接种处理之间无差异；在遭遇干旱胁迫时，双接种疏叶骆驼刺的AMF侵染率、总生物量、Fv/Fm均小于单接种处理；地上生物量、地下生物量、根瘤数、Fm、Fo以及氮含量与单接种之间无差异。复水后，双接种疏叶骆驼刺的地上生物量、地下生物量、总生物量、根瘤数均优于单接种；AMF侵染率、氮含量低于单接种；Fm、Fo、Fv/Fm均与单接种之间无差异。在氮素转移方面，正常水分时，双接种与单接种的氮素转移率无差异，在遭遇干旱胁迫时，双接种疏叶骆驼刺的氮素转移率显著降低，即使复水后，仍得不到恢复。可见，与单接种AMF或单接种根瘤菌相比，双接种AMF和根瘤菌在正常水分时更具有优势，干旱胁迫会导致AMF和根瘤菌协同促生优势的减弱，复水后双接种疏叶骆驼刺能及早的对水分变化做出响应，对其生长具有一定的补偿作用，但仍不能抵消干旱胁迫所带来的损伤。丛枝菌根网络促进氮素转移一定程度上提高了疏叶骆驼刺幼苗耐旱性，但是在干旱条件下双接种疏叶骆驼刺的氮素转移率要低于单接种AMF，复水后仍得不到恢复。 Abstract:In this study, three water gradients and four inoculation treatments were established to analyze the effects of a double inoculation of arbuscular mycorrhizal fungi (AMF) and rhizobia on the growth of Alhagi sparsifolia and nitrogen between the donor and recipient plants. The water gradient included normal water (soil relative water content (70±5)%), drought stress (soil relative water content (20±5)%) and rewatered treatment (return to the water content after 60 days of drought stress). The plants were inoculated singly with AMF or rhizobia. In addition, other plants were inoculated with both organisms (double AMF+rhizobia inoculation), and there was a control of no inoculation. The infection rate of AMF, the aboveground, belowground total biomass and the nitrogen content of double inoculation treatment was higher than that of the single inoculation when there was a normal amount of water. The nodule number, Fm, Fo and Fv/Fm did not differ from those of the single inoculation treatment. However, the AMF infection rate, total biomass and Fv/Fm rate of the double inoculation treatment were all lower than those of single inoculation under drought stress. There was no difference in the aboveground and belowground biomass, nodule number, Fm, Fo and nitrogen content compared with the single inoculation under drought stress. After rehydration, the aboveground, belowground and total biomass and the number of nodules on A. sparsifolia that had been treated with both AMF and rhizobia were higher than those inoculated singly. The rates of infection and nitrogen content rate of AMF after rehydration were lower than those that followed a single inoculation. The values of Fm, Fo, Fv/Fm did not differ from those of the single inoculation. An analysis of the amount of nitrogen transfer indicated that there was no difference between double and single inoculation under normal water conditions. However, the growth of A. sparsifolia that had been double inoculated decreased significantly under drought stress and could not be restored even after rehydration. It was apparent that the double inoculation of AMF and rhizobia compared with their single inoculation provides more benefits when the water content is normal and that drought stress will weaken the ability of AMF and rhizobia to synergistically enhance plant growth. After rehydration, A.sparsifolia that had been treated with both species quickly responded to changes in the water content. This ability can somewhat compensate for the effects of drought stress. However, it still cannot offset the damage. Arbuscular mycorrhizal network promoted nitrogen transfer and increased drought tolerance of A. sparsifoliaseedlings to a certain extent. However, the nitrogen transfer rate of double inoculation was lower than that of the single inoculation of AMF under drought conditions, which could not be reversed after rehydration. 参考文献 相似文献 引证文献

Biodiversity of arbuscular mycorrhizal fungi in plant roots and rhizosphere soil from different arid land environment of Qatar.

Recently more attention has been observed toward the role of arbuscular mycorrhizal fungi (AMF) in plant growth. Qatar belongs to the Arabian Gulf region with hot and dry climatic conditions. The study aims to investigate the species composition and abundance of AMF in Qatar, rhizosphere soil samples, and roots of plants from 12 families and 8 different locations. The AMF were identified based on the sequencing of the polymerase chain reaction (PCR) product of the amplified conserved ITS region. The reported AMF infection rate was found to vary with location and plant species. Tamarix aphylla recorded the highest AMF infection rate (100%), followed by Blepharis ciliaris (98%) and Sporobolus ioclados (92%). AMF spore counts ranged from 29.3 spores in Blepharis ciliaris to 643 spores/100 g soil in Fagonia indica. No correlation was detected between colonization rate and spore counts. While all AMF identified at species levels were reported in other regions, new species are still expected since some were identified only at higher taxonomic levels. Claroideoglomus drummondii and Rhizophagus irregularis were the most widespread while Claroideoglomus claroideum and Diversispora aurantia were the least present. Our results fill the gap of knowledge of AMF in the region and opens new research toward its future applications for sustainable agriculture.

Role of soil biota in grassland restorations in high nutrient soils

Soil biota are abundant in grasslands; however, disturbances such as invasions or conversion to agriculture may alter soil communities in ways that reduce the success of native species and/or increase the competitiveness of invasive plants. Predicting the magnitude and direction of these effects on plant growth remains challenging, particularly in high nutrient soils, which can impact plant‐microbe and plant–plant interactions in different ways. In greenhouse experiments, invasive and native Palouse prairie plants were grown individually and in a community with soil from a Palouse prairie remnant, soil invaded by Bromus tectorum, a nutrient release treatment, or no treatment. We tested (1) whether arbuscular mycorrhizal fungal infectivity and function of soil biota differ in invaded versus remnant prairie soil; (2) if growth responses to soil biota are related to plant nutrient demands; (3) if individual plant responses to soil biota predict competitive outcomes; and (4) if successional status predicts plant growth response to soil biota in high nutrient soils. We found no difference in mycorrhizal inoculation potential or function in invaded versus remnant prairie soil. We show a continuum of plant growth responses to soil biota, which correlate with nutrient responses, even under the high baseline soil nutrient conditions. We found that growth response to soil biota may increase with native plant successional stage. Understanding how different plant species respond to soil biota and assessing functionality of soil biota at a site will help managers plan restorations in high nutrient soils, and inform whether inoculations may be beneficial at a particular site.