Effects of arbuscular mycorrhizal fungal inoculation on soil properties and yield of selected rice varieties

Abstract

Plant growth can be stimulated by a symbiotic relationship between arbuscular mycorrhizal fungi (AMF) and bacteria within the rhizosphere region. These interactions are crucial for increasing soil fertility, which leads to increased productivity and sustainability, as well as food security considering a high level of malnutrition. Six rice varieties were grown with (M+) or without (M-) AMF inoculation in a randomised complete block design with three replicates. The soil physic-chemical properties were determined using standard procedures. Bacteria were isolated from the soil samples and the colony count was determined during the early and late cropping seasons of rice. Specific soil properties (phosphate, pH, organic matter) increased dramatically in the presence of AMF, which led to significant rice yield in both seasons. Bacterial species isolated included Lactobacillus spp., Klebsiella aerogenes, Bacillus subtilis, Escherichia coli, Pseudomonas fluorescens, Azospirillum brasilense, Bacillus subtilis, Staphylococcus aureus, Enterobacter cloacae, and Micrococcus sp. Rice exudates increased the bacterial population in the early season, while AMF treatment increased the bacterial population in the late season and generally increased the bacterial species richness in both seasons. Although the actual mechanism that increased the bacterial species richness was not accessed, this study, however, shows that AMF-bacteria interaction increased and sustained soil fertility which consequently increased rice yield. A further study is necessary to determine the mechanism of the interaction observed between AMF inoculation and bacterial population.

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

“…However, these authors observed that in the treatment with UFLA401, vesicle formation was inhibited as nodulation by nitrogen-fixing bacteria increased. Vesicle formation depends on the AMF x plant interaction, and the nutrition supply of the associated plant to other microorganisms (OKONJI et al, 2018).…”

“…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.…”

Micro-organismos endofíticos e níveis de nitrogênio no crescimento de plantas de arroz

“…In general, urea nitrogen fertilization favored rice growth considering the dry root matter of rice plants without AMF (control) and cultivated with isolates UFLA351 and UFLA401. Mycorrhizal colonization of rice RBS Tropical by UFLAs isolates may reduce nitrogen and phosphorus losses, as well as favor precocity in flowering and maturation, as cited by Okonji et al (2018). Thus, it is important to continue this study, especially at different seasons, since Bernola et al (2018) observed variation in mycorrhizal colonization depending on the year of cultivation.…”

“…Nitrogen fertilization in poaceaus plants cultivated with AMF can promote growth (Püschel et al, 2016) and improve phosphorus absorption (Okonji et al, 2018). Lasudee et al (2018) and Hoseinzade et al (2016) also observed that the association of AMF with nitrogen fertilizers and rhizospheric bacteria stimulated the growth of rice plants in low fertility soils.…”

“…In microbial interaction with host plants, these organisms can: promote plant growth, depending on the interaction (Santos et al, 2018); to induce the plant defense system against pathogens and/or pests (Volpe et al, 2018, Van Heidjen et al, 2015; increase water and nutrient uptake by plants (Atama et al, 2018); reduce the consumption of mineral fertilizers (Ziane et al, 2017); reduce loss of the nitrogen and phosphorus in the soil (Teutscherova et al, 2019;Okonji et al, 2018); and promote tolerance to drought and salinity (Rivero et al, 2015).…”