Ganugi Paola, Fiorini Andrea, Rocchetti Gabriele, Bonini Paolo, Tabaglio Vincenzo, Lucini Luigi
Department for Sustainable Food Process, Università Cattolica del Sacro Cuore, Piacenza, Italy.
Department of Sustainable Crop Production, Università Cattolica del Sacro Cuore, Piacenza, Italy.
Front Plant Sci. 2022 Aug 11;13:956391. doi: 10.3389/fpls.2022.956391. eCollection 2022.
Co-inoculation of arbuscular mycorrhizal fungi (AMF) and bacteria can synergically and potentially increase nitrogen use efficiency (NUE) in plants, thus, reducing nitrogen (N) fertilizers use and their environmental impact. However, limited research is available on AMF-bacteria interaction, and the definition of synergisms or antagonistic effects is unexplored. In this study, we adopted a response surface methodology (RSM) to assess the optimal combination of AMF () and (a PGPR-plant growth promoting rhizobacteria) formulations to maximize agronomical and chemical parameters linked to N utilization in maize ( L.). The fitted mathematical models, and also 3D response surface and contour plots, allowed us to determine the optimal AMF and bacterial doses, which are approximately accorded to 2.1 kg ha of both formulations. These levels provided the maximum values of SPAD, aspartate, and glutamate. On the contrary, agronomic parameters were not affected, except for the nitrogen harvest index (NHI), which was slightly affected (-value of < 0.10) and indicated a higher N accumulation in grain following inoculation with 4.1 and 0.1 kg ha of AMF and , respectively. Nonetheless, the identification of the saddle points for asparagine and the tendency to differently allocate N when AMF or PGPR were used alone, pointed out the complexity of microorganism interaction and suggests the need for further investigations aimed at unraveling the mechanisms underlying this symbiosis.
丛枝菌根真菌（AMF）与细菌共同接种可协同并潜在地提高植物的氮利用效率（NUE），从而减少氮肥的使用及其对环境的影响。然而，关于AMF与细菌相互作用的研究有限，协同作用或拮抗作用的定义尚未得到探索。在本研究中，我们采用响应面法（RSM）来评估AMF（ ）和 （一种促进植物生长的根际细菌，PGPR）配方的最佳组合，以最大化与玉米（L.）氮利用相关的农艺和化学参数。拟合的数学模型以及三维响应面和等高线图使我们能够确定最佳的AMF和细菌剂量，两种配方的剂量约为2.1 kg/ha。这些水平提供了最大的SPAD值、天冬氨酸和谷氨酸值。相反，除了氮收获指数（NHI）外，农艺参数未受影响，氮收获指数受到轻微影响（P值<0.10），表明分别接种4.1 kg/ha的AMF和0.1 kg/ha的 后，籽粒中的氮积累量更高。尽管如此，天冬酰胺鞍点的确定以及单独使用AMF或PGPR时氮分配方式的差异趋势，指出了微生物相互作用的复杂性，并表明需要进一步研究以阐明这种共生关系的潜在机制。
