Traits related to differences in function among three arbuscular mycorrhizal fungi

Abstract

Diversity in phosphorus (P) acquisition strategies was assessed among three species of arbuscular mycorrhizal fungi (AMF) isolated from a single field in Switzerland. Medicago truncatula was used as a test plant. It was grown in a compartmented system with root and root-free zones separated by a fine mesh. Dual radioisotope labeling ( 32 P and 33 P) was employed in the root-free zone as follows: 33 P labeling determined hyphal P uptake from different distances from roots over the entire growth period, whereas 32 P labeling investigated hyphal P uptake close to the roots over the 48 hours immediately prior to harvest. Glomus intraradices, Glomus claroideum and Gigaspora margarita were able to take up and deliver P to the plants from maximal distances of 10, 6 and 1 cm from the roots, respectively. Glomus intraradices most rapidly colonized the available substrate and transported significant amounts of P towards the roots, but provided the same growth benefit as compared to Glomus claroideum, whose Plant Soil (2011) 339:231-245 mycelium was less efficient in soil exploration and in P uptake and delivery to the roots. These differences are probably related to different carbon requirements by these different Glomus species. Gigaspora margarita provided low P benefits to the plants and formed dense mycelium networks close to the roots where P was probably transiently immobilized. Numerical modeling identified possible mechanisms underlying the observed differences in patterns of mycelium growth. High external hyphal production at the rootfungus interface together with rapid hyphal turnover were pointed out as important factors governing hyphal network development by Gigaspora, whereas nonlinearity in apical branching and hyphal anastomoses were key features for G. intraradices and G. claroideum, respectively.

Arbuscular mycorrhizal fungal symbiosis with Sorbus torminalis does not vary with soil nutrients and enzyme activities across different sites

“…In a similar study on Araucaria angustifolia, Moreira et al (2006) showed similar rates of root colonization in spring. A reasonable colonization rate is usually about 40% (Thonar et al 2011). In the present study, based on observation of vesicle, arbuscule and mycelia in roots, AMF colonization rates were more than 51% and 32% of roots in spring and autumn, respectively.…”

Arbuscular Mycorrhizal Fungal Composition Affects the Growth and Nutrient Acquisition of Two Plants from a Karst Area

“…papyrifera and B. pilosa seedlings that received an AM fungal treatment showed positive feedback in terms of biomass and nitrogen and phosphorous acquisition (Figure 1(a), 1(b), 1(c)), which was consistent with the results reported in many related studies showing that AM fungi change the growth and nutrient uptake of their host plants (Gustafson & Casper 2006;Hart et al 2013;Jansa et al 2008;Kiers et al 2011;Thonar et al 2011). Differences in the influence of an AM fungal association on the performance of plant traits for biomass and nitrogen and phosphorus acquisition depending on the plant species and the AM fungal composition have previously been explained as a method of avoiding competition between individuals (Jansa et al 2008;Kiers et al 2011).…”

“…Differences in the influence of an AM fungal association on the performance of plant traits for biomass and nitrogen and phosphorus acquisition depending on the plant species and the AM fungal composition have previously been explained as a method of avoiding competition between individuals (Jansa et al 2008;Kiers et al 2011). Previous studies have shown that inoculating plants with multiple AM fungi was beneficial for the nutritional uptake of the host plant (Gustafson & Casper 2006;Thonar et al 2011), which was consistent with our results for the B. papyrifera seedlings that received the MI treatment (Figure 1(b), 1(c)). However, Edathil et al (1996) and Hart et al (2013) argued that inoculating plants with a single AM fungus can derive the biggest benefit.…”

Arbuscular mycorrhizal fungi associated with citrus orchards under different types of soil management, southern China

“…Hence, the most traditional agricultural practices were unfavorable to enhance the AMF benefits in citrus orchards. In the present study, the higher AMF diversity in SC might be advantageous in improving various orchard ecology functions as different AMF species were highly variable in several functional traits (Thonar et al 2011).…”