Symbiotic fungi and rhizospheric phosphate solubilization in weeds

From the report “Occurrence of symbiotic fungi and rhizospheric phosphate solubilization in weeds“, of Edson Aparecido dos Santos, Lino Roberto Ferreira, Maurício Dutra Costa, Marliane de Cássia Soares da Silva, Marcelo Rodrigues dos Reis and André Cabral França, published at Acta Scientiarum.

arbuscules micorrizes – foto INRA

A total of 36 weed species were evaluated for the occurrence of mycorrhizae in weeds infesting Brazilian crops and to evaluate the inorganic phosphate solubilization potential of the associated microbiota. Of these, 11 were selected to evaluate their potential for total and relative phosphate solubilization.

All of the evaluated species presented colonization by arbuscular mycorrhizal fungi, a symbiosis that has advantages for weeds, including the better access to nutrients, water and protection against soil-borne pathogens. Furthermore, the mycorrhizal colonization included a member of the Brassicaceae family, which is usually assumed to be non-mycorrhizal. The weeds presented different potentials for P solubilization in the rhizosphere; Amaranthus retroflexus, Bidens pilosa and Leonotis nepetaefolia showed high values of relative phosphate solubilization.

A greater ability to extract phosphorus and a greater efficiency in competing with the crops for soil resources was verified in the weeds that had higher potentials of microbial phosphate solubilization.