Plant Development Shapes the Rhizosphere Microbiota Assembly of Cedrela odorata (Meliaceae)

Cedrela odorata L. (Meliaceae), commonly known as Spanish cedar, is a timber species of high interest for mass propagation. However, there are factors that complicate this process, such as poor natural regeneration, rapid loss of seed viability, or slow growth. In this context, examining the rhizosphere microbiota of this species may help devise strategies to improve its establishment during early development. Thus, we conducted a meta-taxonomic analysis of the bacterial and fungal communities associated with the rhizosphere of seedlings and adults of C. odorata and the surrounding bulk soil. We found that the alpha diversity of the microbiota in the rhizosphere was not significantly different between adults, seedlings, and soil samples, whereas the beta diversity showed significant differences between soil and rhizosphere and between developmental stages. We identified several differential genera of bacteria and fungi, including nitrogen-fixing bacteria such as Bradyrhizobium and Pseudolabrys, that could play a beneficial role in the establishment and development of Spanish cedar. This is the first study that surveyed the microbiota associated with Spanish cedar, and the findings obtained may help guide further functional studies and to develop knowledge-based microbial inocula to improve the establishment of this species under field conditions.