Arbuscular Mycorrhizal Fungi and Dark Septate Endophytic Fungi on the Biomass Development of Vetiver Grass

Abstract

Vetiver grass is a member of the grass family Poaceae. Its fast development is probably due to the interaction with native microbiota, whose influence has not been studied yet. The objective of this work was to evaluate the colonization and development of the vetiver grass (Chrysopogon zizanioides (L.) Roberty) inoculated with arbuscular mycorrhizal fungi and dark septate endophytic fungi. The experimental design was a completely randomized design with six treatments (control, without mycorrhizal fungi, native inoculants, UFLA05 - Gigaspora albida, UFLA351 - Rhizoglomus clarum, UFLA372 - Claroideoglomus etunicatum, and UFLA401 - Acaulospora morrowiae), with three replicates each. Vetiver grass tillers as well as the native microbial inoculum were obtained from the Lower São Francisco river experimental area, located in Sergipe state, Northeastern Brazil. There was a negative interaction between all tested UFLAs mycorrhizal isolates and the native microbiota (mycorrhizal and endophytic fungi) in the treatments, especially when taking into consideration plant height and volume of roots. The effects of inoculation with UFLA isolates may have been influenced by the presence of the native mycorrhizal fungi and the dark septate endophytic fungi. Vetiver grass was responsive to the native inoculant. The mycorrhizal colonization of the vetiver grass was vesicular, but the formation of the arbuscules can be influenced by the interaction between the fungus, plant, and the environment.

EXOTIC ARBUSCULAR MYCORRHIZAL FUNGI AND NATIVE DARK SEPTATE ENDOPHYTES ON THE INITIAL GROWTH OF Paspalum millegrana GRASS

“…In the control treatment, the arbuscules: vesicles ratio was null due to the absence of these two mycorrhizal structures, which characterizes the lack of symbiosis and, no nutrient sharing among the symbionts. In P. millegrana grass cultivated with UFLA351, the arbuscules: vesicles ratio has been also null, as also observed in vetiver grass cultivated with the same mycorrhizal isolate (SANTOS et al, 2018a). This result is due only to the absence of vesicles, which may be beneficial to the plant.…”

“…Thus the hypothesis that DSE influences AMF colonization, could not be confirmed, in opposition to the findings reported by Uma et al (2012) in tree species and vetiver grass (SANTOS et al, 2018a). Mandyam and Jumpponen (2008) reported variations in interactions between mycorrhizal and endophytic fungi depending of the host plant growing season and environmental conditions.…”

“…In the treatment containing UFLA372, the presence of hyphae was 3.7 times more hyphae compared to UFLA351, but without significant differences compared to UFLA401 (Table 1). This effect may be correlated to the greater dissemination potential of UFLA372 and may should be generalist in relation to the interaction with plant species, as observed in the studies on vetiver grass (SANTOS et al, 2018a) and Fabaceae Gliricidia sepium (Jacq.) Steud.…”

“…When P. millegrana was cultivated with exotic AMF starting in the spring (early October) and harvested in the summer (December), was observed higher percentage of arbuscules compared to the vesicles. In contrast, Santos et al (2018a) observed that the colonization in vetiver grass was of the vesicular type between the spring and summer seasons. Thus, the presence of vesicles may be influenced by the environment, and also by hostplant interaction.…”

“…In return, the host plants provide the symbiotic fungus with photoassimilates for nutrition. By these interactions, the AMF promotes plant growth (SANTOS et al, 2018a); induces the defense system against pathogens and/or pests (VOLPE et al, 2018;HEIDJEN et al, 2015); increases the absorption of water and nutrients and reduce the consumption of mineral fertilizers (ZIANE et al, 2017); reducing nitrogen and phosphorus losses in the soil (TEUTSCHEROVA et al, 2019;OKONJI et al, 2018), and promoting tolerance to drought and salinity (RIVERO et al, 2018). However, the beneficial effects of AMF symbiosis on the host plant are not restricted to plant growth.…”