Evaluation of plant growth promoting bacteria (PGPR) associated to Ilex paraguariensis.

Yerba mate (Ilex paraguariensis St. Hil.) is a native species of the Atlantic forest of Paraguay, Argentina and Brazil. This species is very valuable in southern South America because it is the source for the mate beverage, a stimulant infusion with similar effects to tea and coffee. Yerba mate is one of the most widespread agricultural activities in Misiones, Argentina, covering 173,000 hectares (Ministerio del Agro y la Produccion, 2002). However, the increase of low productive plantations due to soil degradation is a major concern. Due to the current state of soil erosion and ecological degradation in yerba mate plantations, more sustainable strategies are recommended to promote soil conservation and management of yerba mate agricultural systems. In this context, the general aim of my thesis is to evaluate the native plant growth promoting rhizobacteria (PGPR) associated to yerba mate in order to improve the growth and health of this crop.

The work that has been conducted until today was the characterization and selection in vitro of PGPR isolates as potential inoculants for this crop. Actually, these inoculants are being tested in yerba mate seedlings in nursery.

On the other hand, there are no so many studies about the microbial populations associated to yerba mate. This encouraged us to evaluate the endophytic bacterial populations associated to this crop.

With this information we expect to analyse if there are specific bacterial species associated to yerba mate and which role they can play in this associations.