Seasonal dynamics of dominant species of arbuscular mycorrhizae in burned and unburned sand prairies

1993 ◽  
Vol 71 (12) ◽  
pp. 1625-1630 ◽  
Author(s):  
Shivcharn S. Dhillion ◽  
Roger C. Anderson

Seasonal variation in abundance of spores of arbuscular mycorrhizal fungi was examined for four growing seasons on burned and unburned sand prairies in Illinois. The three leading mycorrhizal species were an undescribed species of Glomus, Scutettospora heterogama, and Sclerocystis rubiformis, in order of decreasing abundance. Mycorrhizal spore abundance for all species generally showed similar seasonal patterns on burned and unburned sites during the sampling period, i.e., minimal in the middle of the growing season and maximal near the end of the season. Individual species, however, exhibited different seasonal patterns of sporulation or sporulation strategies. Burning caused a 2-year depression in spore abundance for Glomus species and Scutellospora heterogama, and a 3-year long depression in spore abundance for Sclerocystis rubiformis. The seasonal patterns observed were more discernible in root zone than in randomly collected soil. Spore abundances were always significantly lower on burned sites than on unburned sites early in the growing season. The results of this study, and studies conducted parallel to this one, suggest that the greater decline in spore abundance in burned sites than in unburned sites early in the growing season may be indirectly due to greater root growth, and (or) related changes in host physiology, in response to fire. Key words: mycorrhizae, fire, sand prairie, grassland, sporulation, inoculum, fungi.

Horticulturae ◽  
2021 ◽  
Vol 7 (7) ◽  
pp. 178
Author(s):  
Matej Vosnjak ◽  
Matevz Likar ◽  
Gregor Osterc

The influence of mycorrhizal inoculum in combination with different phosphorus treatments on growth and flowering parameters of Ajania (Ajania pacifica (Nakai) Bremer et Humphries) plants was investigated in two growing seasons (2015 and 2016). Plants of the cultivar ‘Silver and Gold’ were transplanted into pots either with added mycorrhizal inoculum or without inoculum and assigned to four phosphorus treatments. Mycorrhizal colonization was assessed by evaluating the frequency of colonization, intensity of colonization and density of fungal structures (arbuscules, vesicles, coils and microsclerotia) in the roots. During the growing season, the content of plant available phosphorus in the soil was analyzed, and shoot length, number of shoots, number of inflorescences, number of flowers and flowering time were evaluated. Inoculated Ajania plants were successfully colonized with arbuscular mycorrhizal fungi and dark septate endophytic fungi. In the root segments, hyphae were mainly observed, as well as vesicles, coils, arbuscules and microsclerotia, but in lower density. The density of fungal structures did not differ among phosphorus treatments, but did differ between years, with a higher density of fungal structures in 2016. Mycorrhizal plants developed higher number of shoots in 2016, higher number of inflorescences, higher number of flowers, and they flowered longer compared to uninoculated plants.


2021 ◽  
Vol 11 (20) ◽  
pp. 9466
Author(s):  
Barbara Łata ◽  
Radosław Łaźny ◽  
Sebastian Przybyłko ◽  
Dariusz Wrona

This study investigated the antioxidant status of roots, leaves, and fruit upon microbial inoculation (AMF+PGPR, arbuscular mycorrhizal fungi, and plant growth-promoting rhizobacteria, respectively) of young organically farmed apple trees over two growing seasons. Three cultivars—‘Topaz’, ‘Chopin’, and ‘Odra’—were selected to test the relationship between inoculation and enzymatic and non-enzymatic antioxidant components. The antioxidant metabolism was highly dependent on tissue type and growing season. The greatest effect on antioxidant status following application of the inoculum was found in roots, then leaves, but it was almost negligible in fruit. Roots were influenced most by application of the inoculum in the first growing season, while leaves were influenced most in the second season. Considerable differences between the inoculated and control plants were found for root glutathione reductase (GR) and catalase (CAT) activity, as well as glutathione and ascorbate contents; root phenolics were not influenced by inoculation. In the case of leaves, effect of microbial inoculation on GR activity was revealed in the first growing season, while for global phenolics in the second season, and only the concentration of glutathione was significantly higher in the leaves of inoculated trees in both growing seasons. Leaf ascorbate content and CAT activity were not influenced by the microbial inoculation. The control and inoculated trees expressed a similar total antioxidant capacity, irrespective of the tissue type tested. Furthermore, the response of the cultivars to inoculation varied and also changed in consecutive growing seasons. Based on this study, it is likely that the effect of microbial inoculum as a tool for enhancing health-promoting properties in the fruit of perennial plants is weaker than that described for vegetables where different plant organs are edible.


2014 ◽  
Vol 69 (3) ◽  
pp. 223-236 ◽  
Author(s):  
Mariusz Tadych ◽  
Janusz Błaszkowski

In the years 1994-1995, the occurrence of arbuscular mycorrhizal fungi (AMF) and arbuscular mycorrhizae (AM) in eight successional stages of vegetation of a deflation hollow no. 12 of the Łeba Bar, Poland, was investigated. Early successional stages were colonized by members of the families Gramineae and Juncaceae, being gradually replaced by ericaceous plants in the middle and later stages and by trees in the most advanced stage corresponding to the <em>Empetro nigri-Pinetum</em> plant association. From the 96 soil samples collected, 21 species in three genera of AMF were recovered. The fungi most frequently found were members of the genus <em>Acaulospora</em>. The overall spore abundance, the species_ richness of AMF and the level of AM colonisation increased from stage 1 to reach a maximum in the middle stages and then gradually declined, being lowest in the forested stage 8. The values of the overall spore abundance and those of the abundances of the most frequently occurring AMF species strongly evidenced functioning in nature of the process of host-dependent differentiation of AMF communities. Of the five most numerously represented AMF species, the early colonizer and quickly diminishing in later successional stages was <em>Glomus</em> 107. The mid-late successor was <em>A. koskei</em>, and the latest - <em>Glomus aggregatum</em>. All measures of AMF presence negatively correlated with the content of organic C in the soil and most of them were negatively correlated with soil N-NO3 and P concentrations. In contrast, the occurrence of AMY and AM generally was positively correlated with soil pH and the K content of the soil.


2018 ◽  
Vol 156 (1) ◽  
pp. 46-58 ◽  
Author(s):  
Caixia Liu ◽  
Sabine Ravnskov ◽  
Fulai Liu ◽  
Gitte H. Rubæk ◽  
Mathias N. Andersen

AbstractDeficit irrigation (DI) improves water use efficiency (WUE), but the reduced water input often limits plant growth and nutrient uptake. The current study examined whether arbuscular mycorrhizal fungi (AMF) could alleviate abiotic stress caused by low phosphorus (P) fertilization and DI.A greenhouse experiment was conducted with potato grown with (P1) or without (P0) P fertilization, with AMF (M1+:Rhizophagus irregularisor M2+:Glomus proliferum) or AMF-free control (M−) and subjected to full irrigation (FI), DI or partial root-zone drying (PRD).Inoculation of M1+ and M2+ maintained or improved plant growth and P/nitrogen (N) uptake when subjected to DI/PRD and P0. However, the positive responses to AMF varied with P level and irrigation regime. Functional differences were found in ability of AMF species alleviating plant stress. The largest positive plant biomass response to M1+ and M2+ was found under FI, both at P1 and P0 (25% increase), while plant biomass response to M1+ and M2+ under DI/PRD (14% increase) was significantly smaller. The large growth response to AMF inoculation, particularly under FI, may relate to greater photosynthetic capacity and leaf area, probably caused by stimulation of plant P/N uptake and carbon partitioning toward roots and tubers. However, plant growth response to AMF was not related to the percentage of AMF root colonization. Arbuscular mycorrhizal fungi can maintain and improve P/N uptake, WUE and growth of plants both at high/low P levels and under FI/DI. If this is also the case under field conditions, it should be implemented for sustainable potato production.


2006 ◽  
Vol 21 (4) ◽  
pp. 245-252 ◽  
Author(s):  
Jason L. De Bruin ◽  
Nicholas R. Jordan ◽  
Paul M. Porter ◽  
Sheri C. Huerd

AbstractIntegration of rye (Secale cereale L.) cover crops into the corn (Zea mays L.) soybean [(Glycine max (L.) Merr.] rotation of the upper Midwest USA can provide many agronomic and agroecological benefits. Integration is made difficult by short growing seasons, but may be facilitated by management of key agroecological interactions such as those between rye and soil microbiota. Rye growth was measured and colonization by arbuscular-mycorrhizal fungi (AMF) was determined in greenhouse experiments using soils from seven different management systems from a long-term cropping-systems experiment in southwest Minnesota. Microbial effects on rye growth were not evident before vernalization, but at final harvest (4 weeks after vernalization) soil microbial populations reduced rye shoot and root growth, relative to a pasteurized control inoculum. At final harvest, shoot biomass in 2-year rotations was 17% greater than 4-year rotations, indicating that microbial populations selected for by 4-year rotations may be more deleterious or pathogenic than those selected for by 2-year rotations. Growth of three rye cultivars was examined in all inocula; cultivars differed in their mean response to soil microbiota and their ability to host AMF. These findings suggest that management factors affect interactions between rye and soil microbiota resulting in altered rye growth.


2020 ◽  
Vol 10 (1) ◽  
Author(s):  
Veronika Řezáčová ◽  
Milan Řezáč ◽  
Hana Gryndlerová ◽  
Gail W. T. Wilson ◽  
Tereza Michalová

AbstractIn a globalized world, plant invasions are common challenges for native ecosystems. Although a considerable number of invasive plants form arbuscular mycorrhizae, interactions between arbuscular mycorrhizal (AM) fungi and invasive and native plants are not well understood. In this study, we conducted a greenhouse experiment examining how AM fungi affect interactions of co-occurring plant species in the family Asteracea, invasive Echinops sphaerocephalus and native forb of central Europe Inula conyzae. The effects of initial soil disturbance, including the effect of intact or disturbed arbuscular mycorrhizal networks (CMNs), were examined. AM fungi supported the success of invasive E. sphaerocephalus in competition with native I. conyzae, regardless of the initial disturbance of CMNs. The presence of invasive E. sphaerocephalus decreased mycorrhizal colonization in I. conyzae, with a concomitant loss in mycorrhizal benefits. Our results confirm AM fungi represent one important mechanism of plant invasion for E. sphaerocephalus in semi-natural European grasslands.


1985 ◽  
Vol 15 (6) ◽  
pp. 1061-1064 ◽  
Author(s):  
Paul P. Kormanik

Sweetgum seedlings with vesicular–arbuscular mycorrhizae formed by Glomusetunicatum or Glomusdeserticola in nursery soil with 30 ppm available phosphorus (P) and nonmycorrhizal seedlings grown in nursery soil with 800 ppm available P were outplanted and whole trees were excavated periodically over the next 5 years in the plantation to follow mycorrhizal development. Four months after outplanting, roots of all initially nonmycorrhizal seedlings had formed vesicular–arbuscular mycorrhizae and the degree of root colonization was comparable to that of initially vesicular–arbuscular mycorrhizal seedlings. New feeder roots did not develop on seedlings of any treatment until almost 5 months after planting. By the end of the first growing season and for the remainder of the study, vesicular–arbuscular mycorrhizae development was approximately the same on all seedlings. The proportion of feeder roots colonized by vesicular–arbuscular mycorrhizal fungi stabilized at 65 to 70%; approximately 56% of the cortical tissues of all feeder roots were colonized with arbuscles, vesicles, and hyphae. Periodic assays of the soil in the plantation showed that vesicular–arbuscular mycorrhizal fungal spores gradually declined from an initial high of 3600 spores to 620 spores per 100-cm3 soil sample after 5 years. This decline was probably caused by crown closure of the sweetgum trees which gradually suppressed understory vegetation.


2012 ◽  
Vol 518-523 ◽  
pp. 5381-5384
Author(s):  
Song Mei Shi ◽  
Bo Tu ◽  
Dai Jun Liu ◽  
Xiao Hong Yang

Physic nut (Jatropha curcas Linn., Euphorbiaceae) is one of the hottest biomass energy plant studied by scientists. This paper first reviewed the symbiosis relationship between physic nut and arbuscular mycorrhizal fungi. The researches have showed that diversity of arbuscular mycorrhizal fungi (AMF) exists around the rhizosphere of physic nut. The AMF hyphae colonize root tips of physic nut to develop arbuscular mycorrhizae. The construction of mycorrhizal symbiosis relationship improves the nutritional absorption, promotes the growth and development of seedlings, and enhance the stress tolerance capacity of physic nut. This paper also displays a prospect for mycorrhizal physic nut research in the future, such as mycorrhizal system, the molecular mechanism for stress resistance and gene engineering. As an important resource of biomass energy, mycorrhizal physic nut has a huge exploitation potential and practical value.


1977 ◽  
Vol 55 (1) ◽  
pp. 48-51 ◽  
Author(s):  
D. E. Carling ◽  
J. A. White ◽  
M. F. Brown

The ultrastructure of the interfacial zone which separates the intracellular structures of vesicular-arbuscular mycorrhizal fungi from host cytoplasm has been described in a variety of ways by recent investigators. Evidence is presented here which suggests that previous interpretations of the ultrastructure of the interfacial zone have been based on an artifact of fixation. Using an improved procedure, a dense, granular material was found in the interfacial zone. This material was preserved by simultaneous glutaraldehyde-osmium fixation but not by conventional prefixation and postfixation in glutaraldehyde and osmium, respectively.


1997 ◽  
Vol 75 (2) ◽  
pp. 320-332 ◽  
Author(s):  
R. E. Koske ◽  
J. N. Gemma ◽  
N. Jackson

Small plots of highly maintained turfs of creeping bentgrass (Agrostis palustris cv. Penncross) and velvet bentgrass (Agrostis canina cv. Kingstown) and a marginally maintained stand of annual bluegrass (Poa annua) were sampled intensively over a 15-month period to measure the populations of spores of arbuscular mycorrhizal fungi (AMF) associated with their root systems. Direct isolation of spores and trap cultures were used to assess the AMF communities. Spores of more than 18 species of AMF were isolated. The six dominant species (as measured by the abundance and frequency of occurrence of spores) were Acaulospora mellea, an undescribed species of Acaulospora, Scutellospora calospora, Glomus occultum, Glomus etunicatum, and Entrophospora infrequens. Spores of 17 species of AMF were recovered from the root zones of velvet bentgrass, 15 species from creeping bentgrass, and 14 from annual bluegrass. Soil fertility differed among the three sites, and it was not possible to ascribe differences in the AMF communities in each plot to any particular variable (e.g., host, pH, soil P). Average spore abundance was greatest in the creeping bentgrass plot (191.0 spores/100 mL), next in the velvet bentgrass plot (82.4 spores/100 mL), and least in the bluegrass plot (28.4 spores/100 mL). Spores were recovered from a significantly greater percentage of the samples from the bentgrass plots (88.5 – 96.8%) than from the bluegrass plot (76.6%). Spores of an average of 4.5 species of AMF were isolated monthly from creeping bentgrass, 3.3 from velvet bentgrass and 2.0 from bluegrass. Average species richness and spore abundance were positively correlated in the creeping bentgrass and bluegrass plots (r = 0.77, p = 0.001, and r = 0.68, p = 0.006), but not in the velvet bentgrass plot. Spore abundance showed strong seasonal trends in all three plots (p = 0.03 – 0.001), with numbers increasing from spring until November. Richness and abundance declined from December until the following spring. In the bluegrass area, which experienced summer drought, spore populations and richness also showed a precipitous decline in July and August in the 1st year of the study (1990), but not in the 2nd year (1991). No such summer decline occurred in the bentgrass plots that received irrigation. The AMF community that was circumscribed by direct spore counts from the field usually was highly dissimilar to the community that was estimated by trap cultures initiated using soil from the turf areas. Key words: annual bluegrass, arbuscular mycorrhizal fungi, creeping bentgrass, putting greens, turfgrass, velvet bentgrass.


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