Host identity and phylogeny shape the foliar endophytic fungal assemblages of Ficus.

Gang Wang,Jin Chen,Jin Zhao,Junwei Liu

doi:10.1002/ece3.5568

Abstract

Foliar endophytic fungi (FEF) are diverse and ubiquitously associated with photosynthetic land plants. However, processes shaping FEF assemblages remain poorly understood. Previous studies have indicated that host identity and host habitat are contributing factors, but these factors are often difficult to disentangle. In this study, we studied FEF assemblages from plants grown in a botanical garden, enabling us to minimize the variation in abiotic environmental conditions and fungal dispersal capacity. FEF assemblages from 46 Ficus species were sequenced using next‐generation methods, and the results indicated that closely related host species had clearly differentiated FEF assemblages. Furthermore, host phylogenetic proximity was significantly correlated with the similarity of their FEF assemblages. In the canonical correspondence analysis, eleven leaf traits explained 32.9% of the total variation in FEF assemblages, whereas six traits (specific leaf area, leaf N content, leaf pH, toughness, latex alkaloid content, and latex volume per leaf area) were significant in the first two dimensions of ordination space. In the multiple regression on distance matrix analysis, 21.0% of the total variance in FEF assemblage was explained by both host phylogeny and leaf traits while phylogeny alone explained 7.9% of the variance. Thus, our findings suggest that both evolutionary and ecological processes are involved in shaping FEF assemblages.

Highlights

| INTRODUCTIONEndophytic fungi live within plant tissues without causing visible symptoms (Petrini, 1991; Wilson, 1995)
Foliar endophytic fungi (FEF) are of particular interest to ecologists owing to their potential capacity to modify the fitness of a host plant, for example, by providing protection from microbial pathogens (Arnold et al, 2003) or by reducing herbivore fecundity (González‐Teuber, 2016; Van Bael et al, 2009)
Due to the variation of individual number of Ficus and material avail‐ ability when sampling, the impact of the 11 measured leaf traits on FEF assemblages was only tested for 23 Ficus species that were represented by three individuals each (Table S2)

Summary

| INTRODUCTION

Endophytic fungi live within plant tissues without causing visible symptoms (Petrini, 1991; Wilson, 1995). Studying FEF assemblages in a botanical garden, in which multiple host species live in similar environmental conditions and share the same fungal meta‐community in a relatively small site, may limit the variations due to differences in fungal dispersal capacity and in abiotic environmental conditions, providing an opportunity to better understand other contributing factors, such as host‐imposed habitat filtering. We used the fig collection in the Xishuangbanna Tropical Botanical Garden (XTBG), in which all fig trees grow in a small area (1.3 ha), in the same seminatural environment, in a humid tropical climate, and are exposed to the same community of herbivores and pathogens, to address the following questions: (a) does host identity influence FEF assemblages; (b) does phylogeny of host plants signifi‐ cantly affect FEF assemblages; and (c) do leaf traits filter FEF and contribute to explain the variation in FEF assemblages

| MATERIAL AND METHODS

Findings

| DISCUSSION