Arbuscular mycorrhizal fungi associated with maize plants during hydric deficit.

The objective of this study was to verify the physiological behavior and development of maize plants under hydric deficit inoculated with the AMF Rhizophagus clarus and Claroideoglomus etunicatum and the commercial inoculant ROOTELLA BR in nonsterilized soil as a strategy to mitigate the effects of drought in the crop. Corn seeds were grown and inoculated with R. clarus, C. etunicatum and the commercial inoculant ROOTELLA BR separately at sowing. The plants were grown in a greenhouse and submitted to water deficit in stage V3, keeping the pots at 20% field capacity for 10 days. The first analyses were performed, followed by reirrigation for 2 days, and the analyses were performed again. The experiment was a double factorial, with 2 water treatments (irrigated and water deficit) × 4 inoculation treatments (control, ROOTELLA BR, R. clarus, C. etunicatum) × 5 replicates per treatment, totaling 40 vessels. The results indicate that the plants were able to recover favorably according to the physiological data presented. It is noted that in inoculated plants, there was no damage to the photosynthetic apparatus. These data demonstrate that AMF contribute greatly to better plant recovery after a dry period and a new irrigation period. Inoculation with AMF favors postwater stress recovery in plants.

The arbuscular mycorrhizal fungus Rhizophagus clarus improves physiological tolerance to drought stress in soybean plants.

Soybean (Glycine max L.) is an economically important crop, and is cultivated worldwide, although increasingly long periods of drought have reduced the productivity of this plant. Research has shown that inoculation with arbuscular mycorrhizal fungi (AMF) provides a potential alternative strategy for the mitigation of drought stress. In the present study, we measured the physiological and morphological performance of two soybean cultivars in symbiosis with Rhizophagus clarus that were subjected to drought stress (DS). The soybean cultivars Anta82 and Desafio were grown in pots inoculated with R. clarus. Drought stress was imposed at the V3 development stage and maintained for 7 days. A control group, with well-irrigated plants and no AMF, was established simultaneously in the greenhouse. The mycorrhizal colonization rate, and the physiological, morphological, and nutritional traits of the plants were recorded at days 3 and 7 after drought stress conditions were implemented. The Anta82 cultivar presented the highest percentage of AMF colonization, and N and K in the leaves, whereas the DS group of the Desafio cultivar had the highest water potential and water use efficiency, and the DS + AMF group had thermal dissipation that permitted higher values of Fv/Fm, A, and plant height. The results of the principal components analysis demonstrated that both cultivars inoculated with AMF performed similarly under DS to the well-watered plants. These findings indicate that AMF permitted the plant to reduce the impairment of growth and physiological traits caused by drought conditions.