SPRING-AUTUMN ARBUSCULAR MYCORRHIZA COLONIZATION DYNAMIC IN Iris germanica L. FROM URBAN MICROCLIMATE

Abstract

Nowadays arbuscular mycorrhiza (AM) is widely recognized as one of the most successful plant-fungi partnerships. Although the evidence for ecosystem services provided by these microorganisms is comprehensive, surprisingly few studies document arbuscular mycorrhiza in cities. The aim of this research was to describe arbuscular mycorrhiza (Glomeromycota) colonization pattern across a genotypic and seasonal gradient for Iris germanica. Colonization parameters were assessed for 2160 root segments from six Iris germanica cultivars collected in spring and autumn (two contrasting phenophases). The results showed that Iris germanica presents Paris AM morphotype. Phenophase exercised a significant influence over AM colonization parameters explaining around 70% of variance while the influence of the cultivar was non-significant and explained between 13-18% of variance. Towards autumn AM frequency decreased and average of 18.36% relative to spring while intra-radicular AM spores and vesicles increased on average of 22.73% relative to spring. This study suggests that plant-fungi interaction is controlled by plant metabolic state and decrease of frequency coincides with the debut of leaf senescence and implicitly a reduction of the carbon flux in plant, to which AM fungi react by sporulating.