Long-Term Fertilization Alters Mycorrhizal Colonization Strategy in the Roots of Agrostis capillaris

Abstract

Long-term fertilization targets mycorrhizal fungi adapted to symbiotic exchange of nutrients, thus restricting their colonization potential and re-orienting the colonization strategies. The MycoPatt tool has a high applicability in quantifying the symbiotic process with the identification of mycorrhizal indices and projection of mycorrhizal patterns. Organic treatments increase the symbiotic process, visible in values of colonization frequency and intensity, with about 6% more than the native status of colonization. At the opposite pole, organic-mineral treatments decrease the colonization parameters by up to half of the organic treatment. All of the colonization parameters show significant correlations, except for the arbuscules/vesicle ratio (0.03). All the applied treatments, except for the organic one, record multiple root segments with a colonization degree lower than 10%. The application of treatments changes the strategy of native colonization from a transfer (40%) and storage (37%) to a predominant storage (50%) for organic treatment, and are mainly proliferative between 38–50% in mixed and mineral treatments. The high amount of mineral components increases also the presence of resistance conditions strategies. The use of mycorrhizal pattern maps, with the inclusion of colonization strategies, presents an important direction in understanding the evolution of mutual relations, and to explore in-depth the efficiency of the whole symbiotic process.

Models of mycorrhizal colonization patterns and strategies induced by biostimulator treatments in Zea mays roots

“…Each set of data from treated and untreated variants was filtered and grouped based on intensity, arbuscules, and vesicles, in order to identify the number of clear colonization strategies ( Corcoz et al., 2022b ). Variants with an intensity lower than 10% were considered in the group of resistance colonization conditions; the intensity between 10% and 25% was assessed as proliferative colonization strategy; the roots with an intensity higher than 25% and an arbuscule/vesicle ratio higher than 1.0 were considered in the group of transfer colonization strategy; the roots with an intensity higher than 25% and an arbuscule/vesicle ratio lower than 1.0 were considered in the group of storage colonization strategy ( Corcoz et al., 2022a ). The strategy graph was performed with the package “scatterplot3d” ( Ligges and Mächler, 2003 ).…”

“…Additionally, the maps with the maximum arbuscules and vesicles from each treatment × phenophase combination were extracted to analyze the mycorrhizal expansion and developed structures in the roots. All maps were analyzed with an expanded version of the multi-point analysis method ( Corcoz et al., 2022a ), which permits the simultaneous comparison of different colonized areas from multiple maps. For each mycorrhizal parameter, starting with the second growth stage, the values of all parameters from the previous growth stages were used to create a forecast model.…”

Advanced Research of Rhizosphere Microbial Activity

“…Unfortunately, intensive fertilization and tillage damage AMF diversity, infectiveness, and effectiveness. The developmental strategy of AMF symbiosis can be represented on a map by converting the colonization types of plots to colors [9]. It was demonstrated by investigating the effect of long-term organic and mineral fertilization on AMF root colonization parameters and the colonization pattern of Agrostis capillaris estimated by MycoPatt tool was translated into colors.…”