In its natural distribution, Araucaria araucana is a plant species usually exposed to extreme environmental constraints such as wind, volcanism, fires, and low rainfall. This plant is subjected to long periods of drought, accentuated by the current climate emergency, causing plant death, especially in its early growth stages. Understanding the benefits that both arbuscular mycorrhizal fungi (AMF) and endophytic fungi (EF) could provide plants under different water regimes would generate inputs to address the above-mentioned issues. Here, the effect of AMF and EF inoculation (individually and combined) on the morphophysiological variables of A. araucana seedlings subjected to different water regimes was evaluated. Both the AMF and EF inocula were obtained from A. araucana roots growing in natural conditions. The inoculated seedlings were kept for 5 months under standard greenhouse conditions and subsequently subjected to three different irrigation levels for 2 months: 100, 75, and 25% of field capacity (FC). Morphophysiological variables were evaluated over time. Applying AMF and EF + AMF yielded a noticeable survival rate in the most extreme drought conditions (25% FC). Moreover, both the AMF and the EF + AMF treatments promoted an increase in height growth between 6.1 and 16.1%, in the production of aerial biomass between 54.3 and 62.6%, and in root biomass between 42.5 and 65.4%. These treatments also kept the maximum quantum efficiency of PSII (Fv/Fm 0.71 for AMF and 0.64 for EF + AMF) stable, as well as high foliar water content (>60%) and stable CO₂ assimilation under drought stress. In addition, the EF + AMF treatment at 25% FC increased the total chlorophyll content. In conclusion, using indigenous strains of AMF, alone or in combination with EF, is a beneficial strategy to produce A. araucana seedlings with an enhanced ability to tolerate prolonged drought periods, which could be of great relevance for the survival of these native species under the current climate change.

<![CDATA[Free-living mycorrhizal-arbuscular and saprophytic fungi have been reported to be able to promote the growth of some plants. However, the combined use of ectomycorrhizal and saprophytic fungi as growth stimulators for forest species has not been much studied to date. To study the effectiveness of different biological inoculants prepared with the ectomycorrhizal fungi Suillus luteus and Rhizopogon luteolus and the saprophytic fungi Coriolopsis rigida and Trichoderma harzianum, in both isolated and combined form, as potential biofertilizers for the growth of Pinus radiata seedlings in greenhouse conditions, P. radiata plants were transplanted to individual containers with pine bark composted as substrate and inoculated with sporal inoculum of ectomycorrhizal fungi and solid mycelial inoculum of saprophytic fungi produced on wheat grains. When the assays were completed (10 months), the percentage of mycorrhization and some morphological parameters of the plants were measured to determine quality indices. The biological inoculants formulated with the saprophytic fungi or with the mixture of saprophytic and ectomycorrhizal fungi stimulated plant growth compared to the controls (plants without fungal inoculation). In addition, the presence of wheat grains in the inocula promoted the stimulating effect produced by the fungi on the growth of P. radiata. The inoculant formulated with the C. rigida-R. luteolus mixture produced P. radiata plants with higher quality indices under greenhouse conditions, and its use as a potential biofertilizer represents a viable alternative in the production of forest plant species.]]>