Spores abundance and diversity of arbuscular mycorrhizal fungi in the Caldenal Forest, Argentina

ONTIVERO R. E.; RISIO, L. V.; LUGO M. A.

Bariloche

Workshop; II International Symposium Mycorrhizal Symbiosis in South America; 2019

Universidad Nacional del Comahue, Universidad Austral de Chile

Arbuscular mycorrhizal fungi (AMF, phylum Glomeromycota) are biotrophic mutualistic symbionts of the 80% of the terrestrial plants; they increase the growth of their hosts through the contribution in the absorption of water and nutrients by means of its extensive network of mycelium in the soil. AMF mycelium and spores are continuous components of biological soil community. The different taxa differ in their edaphic and nutritional preferences, in the ranges of host species and in the seasonal changes in sporulation. The increase in world population and the global demand for natural resources, particularly food, acted as an important driving force for agricultural changes in Argentina in the last 150 years. In this stage, a territory of high agricultural productivity (current or potential) and low population such as the center of Argentina experienced a drastic change. Particularity in Espinal ecoregion, the synergy of natural and / or anthropogenic changes have modified profoundly the dynamics of the xeric forests that dominated the region. Thus, in the province of San Luis, the forest of Prosopis caldenia Burkart (or "caldenales"), experienced a reduction of approximately 12.600 ha in the last 10 years. This changes likely have affected soil community, for that reason is important to know the AMF community that lives in the Caldenal Forest soil. The main objective of this work was known AMF spores diversity in different patches in Caldenal Forest. The sampling sites were four forest patches in San Luis (Argentina). Soil samples (0?20 cm deep) were collected, packed in plastic bags and transported to the laboratory. Glomerospores were extracted from 100g of field soil from each sample by wet sieving followed by sucrose centrifugation and quantified using an optical microscopy. Species identification was performed with the aid of a defined bibliography, publications with descriptions of new species and by INVAM database. Total number spores change in different patches, one patch showed Shannon-Wienner index and Simpson's Diversity index values very different from others. These differences could be caused by different factors such as the history of use or the diversity of plant species present. This work will serve as a starting point for later studies comparing the diversity of AMF between areas with different land uses and for the analysis of the potential ecosystem services of AMF in the Caldenal.