Tolerance to Fusarium wilt and anthracnose diseases and changes of antioxidative activity in mycorrhizal cyclamen

Mycorrhizal associations imply a remarkable reprogramming of functions in both plant and fungal symbionts. This consequent alteration on plant physiology has a clear impact on the plant responses to biotic stress management. As a consequence, a pot experiment was conducted to study the interactions between the arbuscular mycorrhizal fungus (AMF) Glomus fasciculatum and the two pathogens Fusarium oxysporum and Colletotrichum gloeosporioides and subsequent effect on growth, disease tolerance and the changes in antioxidative ability in cyclamen plants under growth chamber condition were investigated. At plant maturity, inoculation with E oxysporum and C gloeosporioides, responsible for Fusarium wilt and anthracnose of cyclamen respectively, significantly reduced shoot and root dry weights, increased both the disease incidence percentage and showed lower antioxidative activity viz. superoxide dismutase (SOD), ascorbate peroxidase (APX), ascorbic acid (AA) and polyphenol contents in plants. In contrast, the growth response and biomass production of cyclamen plants inoculated with AMF was significantly higher than the nonmycorrhizal control plants, both in the presence and absence of the pathogens. Mycorrhization enhanced plants to reduce the Fusarium wilt and anthracnose incidence compared to nonmycorrhizal controls. In every case, without and with pathogen association, plants inoculated with AMF increased the antioxidant (SOD, APX, AA and polyphenol) production compared to control plants. The results demonstrate that AMF have the ability to induce resistance against Fusarium wilt and anthracnose in cyclamen by increasing the antioxidative activity in plants, which promoted plant growth, biomass production and drastically reduced the disease incidence in cyclamen. (C) 2013 Elsevier Ltd. All rights reserved.