Abstract

CASTANON-SILVA, Paulina A.; VENEGAS-URRUTIA, Michael A.; LOBOS-VALENZUELA, María G.  and  GAETE-OLIVARES, Hernán J.. Influence of arbuscular mycorrhizal Glomus spp. On growth and accumulation of copper in sunflower Helianthus annuus L.. Agrociencia [online]. 2013, vol.47, n.4, pp.309-317. ISSN 2521-9766.

The copper (Cu) mining activity in Chile generates large amounts of toxic wastes that pollute soils; an alternative to recuperate these soils is to use mycorrhizae, soil microorganisms adapted to this condition, to inoculate plant roots. The objective of this study was to determine the influence of arbuscular mycorrhizae (AM) of the Glomus spp. genus on the growth and accumulation of Cu in sunflower (Helianthus annuus L.). In the Aconcagua River basin, central Chile, soil samples polluted by Cu were collected; soils 1 and 2 of the Catemu Valley and soil 3 of the Puchuncaví Valley. In these soils, inoculated (M⁺) and not inoculated (M^-) with AM sunflower seeds were planted. After 50 d, dry biomass was measured, as well as mycorrhizal colonization and Cu concentration in the plant tissues. The soils presented a sandy-loam texture and were characterized by 3.5 to 12.8 % of organic matter, pH 6.7 to 6.9, total Cu 382 to 7678 mg kg ^-1, and Cu available 72 to 574 mg kg ^-1. The greatest growth of plants occurred in M⁺ treatments (p≤0.05) as compared to their M^- witnesses. There was a significant decrease (p≤ 0.05) in colonization (67, 32 and 58 %) when increasing the Cu in the soil and M⁺ plants presented a higher capacity to accumulate Cu (285-697 mg kg ^-1) in the three soils as compared to their M witnesses. The Cu accumulation was higher in the root than in the aerial tissue. It is concluded that the AMs (Glomus spp.) contributed to the growth and accumulation of Cu in sunflower, favoring the processes of soil recuperation.

Keywords : mycorrhizal colonization; phytostabilization and Helianthus annuus L.