Beta Diversity of Arbuscular Mycorrhizal Communities Increases in Time after Crop Establishment of Peruvian Sacha Inchi (Plukenetia volubilis)

Abstract

(1) Background: Beta diversity, i.e., the variance in species compositions across communities, has been pointed out as a main factor for explaining ecosystem functioning. However, few studies have directly tested the effect of crop establishment on beta diversity. We studied beta diversity patterns of arbuscular mycorrhizal (AM) fungal communities associated to sacha inchi (Plukenetia volubilis) after crop establishment. (2) Methods: We molecularly characterized the AM fungal communities associated to roots of sacha inchi in plots after different times of crop establishment, from less than one year to older than three. We analyzed the patterns of alpha, beta, and phylogenetic diversity, and the sources of variation of AM fungal community composition. (3) Results: Beta diversity increased in the older plots, but no temporal effect in alpha or phylogenetic diversity was found. The AM fungal community composition was driven by environmental factors (altitude and soil conditions). A part of this variation could be attributed to differences between sampled locations (expressed as geographic coordinates). Crop age, in turn, affected the composition with no interactions with the environmental conditions or spatial location. (4) Conclusions: These results point out towards a certain recovery of the soil microbiota after sacha inchi establishment. This fact could be attributed to the low-impact management associated to this tropical crop.

Arbuscular Mycorrhizal Fungi Associated with Myrciaria dubia in the Amazonia Region, Peru

“…Root colonization by AMF is characterized by presenting fungal structures, such as mycelium, auxiliary cells, arbuscules, vesicles, and spores [18,19], being this vast structure it is most important for its correct identification using the morphological approach [18][19][20][21][22]. Currently, in the Peruvian Amazon, some studies have recorded a great diversity of AMF [23][24][25][26][27]. New species were identified in different crops [23,[28][29][30][31][32][33][34][35][36][37][38] using morphological and molecular tools [39][40][41], and molecular analyses of the SSU-ITS-LSU region of rDNA [42].…”