scholarly journals AM Fungi Endow Greater Plant Biomass and Soil Nutrients under Interspecific Competition Rather Than Nutrient Releases for Litter

Forests ◽  
2021 ◽  
Vol 12 (12) ◽  
pp. 1704
Author(s):  
Bangli Wu ◽  
Yun Guo ◽  
Minhong He ◽  
Xu Han ◽  
Lipeng Zang ◽  
...  
Keyword(s):  
Interspecific Competition ◽  
Litter Decomposition ◽  
Soil Nutrients ◽  
Intraspecific Competition ◽  
Plant Biomass ◽  
Nitrogen Concentration ◽  
Plant Competition ◽  
Nutrient Release ◽  
Am Fungi ◽  
Am Fungus

Plant competition affects belowground ecological processes, such as litter decomposition and nutrient release. Arbuscular mycorrhizal (AM) fungi play an essential role in plant growth and litter decomposition potentially. However, how plant competition affects the nutrient release of litter through AM fungi remains unclear especially for juvenile plants. In this study, a competitive potting experiment was conducted using juvenile seedlings of Broussonetia papyrifera and Carpinus pubescens from a karst habitat, including the intraspecific and interspecific competition treatments. The seedlings were inoculated by AM fungus or not inoculated, and the litter mixtures of B. papyrifera and C. pubescens were added into the soil or not added. The results were as follows: Litter addition significantly increased the root mycorrhizal colonization of two species in intraspecific competition. AM fungus significantly increased the biomass of B. papyrifera seedings and nitrogen release and decreased nitrogen concentration and N/P ratio of litter and further improved the total nitrogen and N/P ratio of soil under litter. The interspecific competition interacting with AM fungus was beneficial to the biomass accumulation of B. papyrifera and improvement of soil nutrients under litter. However, intraspecific competition significantly promoted nutrient releases via AM fungus. In conclusion, we suggest that AM fungi endow greater plant biomass and soil nutrients through interspecific competition, while intraspecific competition prefers to release the nutrients of litter.

Competition between endoparasitic nematodes and effect on biomass of Ammophila arenaria (marram grass) as affected by timing of inoculation and plant age

Nematology ◽  
2005 ◽  
Vol 7 (2) ◽  
pp. 169-178 ◽  
Author(s):  
Wim van der Putten ◽  
Henk Duyts ◽  
E. Pernilla Brinkman
Keyword(s):  
Interspecific Competition ◽  
Intraspecific Competition ◽  
Plant Biomass ◽  
Nematode Species ◽  
Pratylenchus Penetrans ◽  
Agricultural Systems ◽  
Ammophila Arenaria ◽  
Marram Grass ◽  
Natural Dune ◽  
Dune Grass

AbstractWe studied the effects of intra- and interspecific competition on the abundance of endoparasitic nematodes and assessed the consequences for biomass production of the natural dune grass Ammophila arenaria. Pratylenchus penetrans was limited by intraspecific competition and it suppressed the abundance of Heterodera arenaria, whilst the interaction between H. arenaria and Meloidogyne maritima was neutral. Pratylenchus penetrans and H. arenaria reduced plant biomass, whereas M. maritima did not. Plant biomass was not differently affected by adding one or two nematode species. When added to older plants, numbers of H. arenaria and M. maritima were higher but numbers of P. penetrans were lower, resulting in less reduction of plant biomass. We discuss our results on this natural system with respect to patterns of interspecific nematode competition observed in agricultural systems.

scholarly journals Arbuscular Mycorrhizal Fungus Improves Rhizobium–Glycyrrhiza Seedling Symbiosis under Drought Stress

Agronomy ◽  
2019 ◽  
Vol 9 (10) ◽  
pp. 572 ◽  
Author(s):  
Zhipeng Hao ◽  
Wei Xie ◽  
Xuelian Jiang ◽  
Zhaoxiang Wu ◽  
Xin Zhang ◽  
...  
Keyword(s):  
Drought Stress ◽  
Nitrogen Concentration ◽  
Mycorrhizal Fungus ◽  
Arbuscular Mycorrhizal ◽  
Am Fungi ◽  
Tolerance Index ◽  
Mycorrhizal Dependency ◽  
Plant Nitrogen ◽  
Water Regimes ◽  
Am Fungus

Rhizobia and arbuscular mycorrhizal (AM) fungi can potentially alleviate the abiotic stress on the legume Glycyrrhiza (licorice), while the potential benefits these symbiotic microbes offer to their host plant are strongly influenced by environmental factors. A greenhouse pot experiment was conducted to investigate the effects of single and combined inoculation with a rhizobium Mesorhizobium tianshanense Chen and an AM fungus Rhizophagus irregularis Walker & Schuessler on Glycyrrhiza uralensis Fisch. seedling performance under different water regimes. Drought stress inhibited rhizobium nodulation but increased mycorrhizal colonization. Furthermore, co-inoculation of rhizobium and AM fungus favored nodulation under both well-watered and drought stress conditions. Glycyrrhiza seedling growth showed a high mycorrhizal dependency. The seedlings showed a negative growth dependency to rhizobium under well-watered conditions but showed a positive response under drought stress. R. irregularis-inoculated plants showed a much higher stress tolerance index (STI) value than M. tianshanense-inoculated plants. STI value was more pronounced when plants were co-inoculated with R. irregularis and M. tianshanense compared with single-inoculated plants. Plant nitrogen concentration and contents were significantly influenced by inoculation treatments and water regimes. R. irregularis inoculation significantly increased plant shoot and root phosphorus contents. AM fungus inoculation could improve Glycyrrhiza plant–rhizobium symbiosis under drought stress, thereby suggesting that tripartite symbiotic relationships were more effective for promoting plant growth and enhancing drought tolerance.

An Alternative Approach for Evaluating the Efficacy of Potential Biocontrol Agents of Weeds. 1. Inverse Linear Model

Weed Science ◽  
1989 ◽  
Vol 37 (6) ◽  
pp. 771-777 ◽  
Author(s):  
Dan J. Pantone ◽  
William A. Williams ◽  
Armand R. Maggenti
Keyword(s):  
Interspecific Competition ◽  
Linear Model ◽  
Intraspecific Competition ◽  
Field Experiments ◽  
Biocontrol Agent ◽  
Plant Biomass ◽  
Biocontrol Agents ◽  
Weed Host ◽  
Classical Biocontrol ◽  
Average Plant

Methods for evaluating the efficacy of potential classical biocontrol agents were outlined for a model biocontrol agent-weed-crop system. A proposed biocontrol agent (the fiddleneck flower gall nematode), its weed host (coast fiddleneck), and wheat were used as representative organisms. An additive experimental design (inverse linear model) was used. Regression of the reciprocal of the average plant biomass of each species onto the density of itself and the other plant species yielded competitive indices that measure the competitive ability of the plants. The results of 2 yr of field experiments revealed a dramatic change in the competitive interaction between fiddleneck and wheat due to the nematode. During the 1986–87 season in the absence of the nematode, fiddleneck intraspecific competition was 33 times stronger than interspecific competition with wheat. In the presence of the nematode, intra- and interspecific competition of fiddleneck were nearly equal. Only the coefficients that measure interspecific competition changed significantly in the presence of the nematode while the coefficients for intraspecific competition did not.

scholarly journals Seeding year alfalfa population development as influenced by weed competition and density of establishment

1980 ◽  
Vol 52 (4) ◽  
pp. 403-422
Author(s):  
Seppo Pulli
Keyword(s):  
Interspecific Competition ◽  
Intraspecific Competition ◽  
Competitive Ability ◽  
Plant Competition ◽  
Maximum Yield ◽  
Michigan State University ◽  
Total Biomass ◽  
State University ◽  
Seeding Rate ◽  
Yield Level

The research in intraspecific competition within an alfalfa stand and interspecific competition between alfalfa and weeds was begun on the Michigan State University farm in East Lansing in 1972. Alfalfa seeding densities of 50, 400 and 800 seeds/m2 were used to determine intraspecific competition. Interspecific competition between alfalfa and weeds occurred mainly in noncontrolled alfalfa stands at various levels of seeding densities. Plant competition was evaluated with importance values and with relative crowding coefficients. Both measurements were found to be suitable for this kind of study. Importance values primarily indicated the quantity relationships of different species. Relative crowding coefficients mainly characterized the competitive ability of a species in a mixed stand. The importance of alfalfa exceeded the importance of weeds in noncontrolled and herbicide controlled stands at the seeding rates of 14 and 7 kg/ha respectively. Relative crowding coefficients show the competitive ability of alfalfa with regard to weeds. In the case of intraspecific competition there was no change in the crowding coefficient of alfalfa in respect of weeds when the seeding rate of alfalfa was increased beyond 9 kg/ha. The crowding coefficient of weeds presented equal values under all treatments thereby indicating the variability and plasticity of weeds. The maximum yield level was obtained in all treatments with the alfalfa seeding rate of 9 kg/ha. The total biomass production per unit area was equal in the noncontrolled system at all seeding densities and in the herbicide controlled system at seeding rates of 9 kg/ha or more.

scholarly journals Litter decomposition and nutrient release dynamics of leaves and roots of the babassu palm in eastern Amazonia

2020 ◽  
Vol 50 (3) ◽  
pp. 213-222
Author(s):  
Ronildson Lima LUZ ◽  
Márcio Fernandes Alves LEITE ◽  
Marcelo Correa ZELARAYÁN ◽  
Robert Michael BODDEY ◽  
Christoph GEHRING
Keyword(s):  
Litter Decomposition ◽  
Secondary Forest ◽  
Nitrogen Concentration ◽  
Acacia Mangium ◽  
Nutrient Release ◽  
Nutrient Concentrations ◽  
Reference Species ◽  
Babassu Palm ◽  
Biomass Loss ◽  
Leaves And Roots

ABSTRACT The ruderal babassu palm (Attalea speciosa) is expanding on large areas of degraded Amazon landscapes. Decomposition of leaves and roots is in the center of plant:soil interactions. We evaluated decomposition and nutrient concentrations of leaves and fine roots of babassu in comparison with two exotic reference species, Acacia mangium (slow degradability) and Leucaena leucocephala (fast degradability), in a 138-day litterbag assay carried out in secondary forest stands of different age and babassu abundance. We chose 4-mm over 2-mm mesh litterbags based on a pilot study. Babassu leaves degraded slower than leaves of A. mangium and L. leucocephala, and also had lower nitrogen, phosphorus and calcium concentrations in all stages of decomposition. By contrast, potassium concentrations in babassu leaves were higher than in both reference species at 0 and 50 days. Roots of all three species decomposed slower than leaves. Compared to the leaves, both biomass loss and nutrient concentrations differed less between babassu and reference-species roots, except for lower nitrogen concentration in babassu roots. Leaf-litter decomposition of all three species was significantly faster in old than in young secondary forest, suggesting an acceleration of decomposition along succession. Babassu leaves decomposed faster in old babassu-dominated than non-dominated secondary forest, pointing to the existence of specialized decomposer communities in babassu-dominated stands.

scholarly journals Ectomycorrhizal Fungal Inoculation of Sphaerosporella brunnea Significantly Increased Stem Biomass of Salix miyabeana and Decreased Lead, Tin, and Zinc, Soil Concentrations during the Phytoremediation of an Industrial Landfill

2020 ◽  
Vol 6 (2) ◽  
pp. 87 ◽  
Author(s):  
Dimitri J. Dagher ◽  
Frédéric E. Pitre ◽  
Mohamed Hijri
Keyword(s):  
Trace Element ◽  
Mycorrhizal Fungi ◽  
Plant Biomass ◽  
Arbuscular Mycorrhizal ◽  
Am Fungi ◽  
Symbiotic Associations ◽  
Growing Seasons ◽  
Abiotic Stressors ◽  
Sphaerosporella Brunnea ◽  
Am Fungus

Fast growing, high biomass willows (Salix sp.) have been extensively used for the phytoremediation of trace element-contaminated environments, as they have an extensive root system and they tolerate abiotic stressors such as drought and metal toxicity. Being dual mycorrhizal plants, they can engage single or simultaneous symbiotic associations with both arbuscular mycorrhizal (AM) fungi and ectomycorrhizal (EM) fungi, which can improve overall plant health and growth. The aim of this study was to test the effect of these mycorrhizal fungi on the growth and trace element (TE) extraction potential of willows. A field experiment was carried out where we grew Salix miyabeana clone SX67 on the site of a decommissioned industrial landfill, and inoculated the shrubs with an AM fungus Rhizophagus irregularis, an EM fungus Sphaerosporella brunnea, or a mixture of both. After two growing seasons, the willows inoculated with the EM fungus S. brunnea produced significantly higher biomass. Ba, Cd and Zn were found to be phytoextracted to the aerial plant biomass, where Cd presented the highest bioconcentration factor values in all treatments. Additionally, the plots where the willows received the S. brunnea inoculation showed a significant decrease of Cu, Pb, and Sn soil concentrations. AM fungi inoculation and dual inoculation did not significantly influence biomass production and soil TE levels.

The Role of Allelopathy in Buckwheat (Fagopyrum sagittatum) Inhibition of Canada Thistle (Cirsium arvense)

Weed Science ◽  
1995 ◽  
Vol 43 (1) ◽  
pp. 70-74 ◽  
Author(s):  
Steven R. Eskelsen ◽  
Garvin D. Crabtree
Keyword(s):  
Interspecific Competition ◽  
Intraspecific Competition ◽  
Plant Biomass ◽  
Niche Differentiation ◽  
Canada Thistle ◽  
Mutual Inhibition ◽  
Replacement Series ◽  
Mutual Antagonism ◽  
Inhibition Data

A replacement series experiment was conducted in the field to quantify the interaction between Canada thistle and buckwheat, and to determine if allelopathy was the mechanism of interference. Plant biomass data indicated that buckwheat only responded to intraspecific competition and not interspecific competition from Canada thistle. Canada thistle responded to interspecific competition from buckwheat plants but not to intraspecific competition. The absence of one of the interspecific competition components (no measurable effect of Canada thistle density on buckwheat) indicates that the value for niche differentiation is probably greater than unity, signifying that there is no mutual antagonism between buckwheat and Canada thistle. Because allelopathy is one mechanism that causes mutual inhibition, data do not support the hypothesis that buckwheat interferes with Canada thistle by allelopathy.

Effects of nitrogen deposition on litter decomposition and nutrient release mediated by litter types and seasonal change in a temperate forest

2020 ◽  
Vol 100 (1) ◽  
pp. 11-25 ◽  
Author(s):  
Guoyong Yan ◽  
Xiongde Dong ◽  
Binbin Huang ◽  
Honglin Wang ◽  
Ziming Hong ◽  
...  
Keyword(s):  
Mass Loss ◽  
Litter Decomposition ◽  
Nutrient Release ◽  
N Deposition ◽  
Pinus Koraiensis ◽  
N Addition ◽  
Entire Study ◽  
Mixed Litter ◽  
Negative Effect ◽  
Four Levels

We conducted a field experiment with four levels of simulated nitrogen (N) deposition (0, 2.5, 5, and 7.5 g N m−2 yr−1, respectively) to investigate the response of litter decomposition of Pinus koraiensis (PK), Tilia amurensis (TA), and their mixture to N deposition during winter and growing seasons. Results showed that N addition significantly increased the mass loss of PK litter and significantly decreased the mass loss of TA litter throughout the 2 yr decomposition processes, which indicated that the different responses in the decomposition of different litters to N addition can be species specific, potentially attributed to different litter chemistry. The faster decomposition of PK litter with N addition occurred mainly in the winter, whereas the slower decomposition of TA litter with N addition occurred during the growing season. Moreover, N addition had a positive effect on the release of phosphorus, magnesium, and manganese for PK litter and had a negative effect on the release of carbon, iron, and lignin for TA litter. Decomposition and nutrient release from mixed litter with N addition showed a non-additive effect. The mass loss from litter in the first winter and over the entire study correlated positively with the initial concentration of cellulose, lignin, and certain nutrients in the litter, demonstrating the potential influence of different tissue chemistries.

scholarly journals Target of rapamycin, PvTOR, is a key regulator of arbuscule development during mycorrhizal symbiosis in Phaseolus

2021 ◽  
Vol 11 (1) ◽  
Author(s):  
Manoj-Kumar Arthikala ◽  
Kalpana Nanjareddy ◽  
Lourdes Blanco ◽  
Xóchitl Alvarado-Affantranger ◽  
Miguel Lara
Keyword(s):  
Arbuscular Mycorrhizal ◽  
Am Fungi ◽  
Target Of Rapamycin ◽  
Mycorrhizal Symbiosis ◽  
Energy Status ◽  
Symbiotic Associations ◽  
Expression Of Genes ◽  
Fungal Symbiosis ◽  
Am Fungus ◽  
Am Symbiosis

AbstractTarget of rapamycin (TOR) is a conserved central growth regulator in eukaryotes that has a key role in maintaining cellular nutrient and energy status. Arbuscular mycorrhizal (AM) fungi are mutualistic symbionts that assist the plant in increasing nutrient absorption from the rhizosphere. However, the role of legume TOR in AM fungal symbiosis development has not been investigated. In this study, we examined the function of legume TOR in the development and formation of AM fungal symbiosis. RNA-interference-mediated knockdown of TOR transcripts in common bean (Phaseolus vulgaris) hairy roots notably suppressed AM fungus-induced lateral root formation by altering the expression of root meristem regulatory genes, i.e., UPB1, RGFs, and sulfur assimilation and S-phase genes. Mycorrhized PvTOR-knockdown roots had significantly more extraradical hyphae and hyphopodia than the control (empty vector) roots. Strong promoter activity of PvTOR was observed at the site of hyphal penetration and colonization. Colonization along the root length was affected in mycorrhized PvTOR-knockdown roots and the arbuscules were stunted. Furthermore, the expression of genes induced by AM symbiosis such as SWEET1, VPY, VAMP713, and STR was repressed under mycorrhized conditions in PvTOR-knockdown roots. Based on these observations, we conclude that PvTOR is a key player in regulating arbuscule development during AM symbiosis in P. vulgaris. These results provide insight into legume TOR as a potential regulatory factor influencing the symbiotic associations of P. vulgaris and other legumes.

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