SEPTATE ENDOPHYTIC FUNGI, BUT NOT ARBUSCULAR MYCORRHIZAL FUNGI AFFECT THE EARLY GROWTH OF QUERCUS HINTONII, AN ENDEMIC OAK FROM MEXICO STATE

Background: The oaks are associated with mycorrhizal and septate-endophytic fungi; however, we unknown how these fungi mpact its development. Question: How does the interaction between arbuscular mycorrhizal fungi (AMF) and septate endophytic fungi (SEF) affect the development of Q. hintonii? Species study: Quercus hintonii Study site and years of study: Tejupilco region, State of Mexico, 2015 Methods: Two experiments with oak seedlings were designed: I) Sphagnum (Sph) with and without mycorrhizal inoculum, and II) Natural forest soil (NFS) and Sphagnum without (NFS/Sph) and with mycorrhizal inoculum (NFS+I/Sph+I). Seedlings growth and its roots fungal colonization were evaluated at 4, 6 and 7 old months (Exp. I), and at 4 old months (Exp. II). Results: The Q. hintonii roots were not colonized by AMF, but if by SEF, which developed moniliform cells (32 %), septate mycelium (51 %) and other structures (7 %). Seedlings of six and seven old months had lower colonization by SEF (12-14 %). Oak inoculated seedlings of 4old months and with higher colonization by SEF, had greater total biomass, number of leaves, dry weight of leaves and roots, and thicker stems. In experiment II, Q. hintonii seedlings grown in NFS had greater root length and total biomass than those grown in NFS+I, Sph+I, and Sph. Septate mycelium and microsclerotia of SEF were abundant in NFS and NFS+I. Conclusions: The colonization by native SEF in Q. hintonii roots favored early development of the seedlings, while the AMF did not interact with this oak species.