Diagnose of Indigenous Arbuscular Mycorrhizal Communities Associated to Cynara cardunculus L. var. altilis and var. sylvestris.

Abstract

Cynara cardunculus L. is a perennial species with high potential for bioenergy production. Arbuscular mycorrhizal symbiosis (AMF) is probably the terrestrial symbiosis most extended on earth. It presence in roots and soils improves plant nutrition and soil quality. Indigenous AMF have developed a variety of modifications to survive in their habitat and thus could serve as potential inoculants for the implantation of plant species in the respective AMF soil habitat. This work aimed to diagnose the status of the AMF symbiosis associated to two cardoon cultivars after a year of growth in a saline soil and in a conventional farming soil. For that purpose we determined AMF parameters in 4 rhizospheric soils and in roots of the cardoon varieties. We found that: (1) the rhizosphere of C. cardunculus var. altilis positively influenced the extraradical mycelium development in the saline soil, (2) the inorganic fertilization history of the conventional farming soil could have had a negative effect on the AMF community and, (3) the intraradical mycelium (IRM) development was extremely low. Our diagnosis suggests that, in order to improve the positive effects of AMF on cardoon growth and soil quality, efforts should be focused on the development of the IRM. In a boarder sense, the implementation of a diagnosis of indigenous AMF communities as a general agronomic practice could become an useful tool to farmers that are willing to potentiate the benefits of AMF on plant growth and soil quality.