BIOREGULATION POTENTIAL OF ARBUSCULAR MYCORRHIZAL FUNGI ON HEAT STRESS AND ANTHRACNOSE TOLERANCE IN CYCLAMEN

Cyclamen (Cyclamen persicum) is one of the most popular ornamental pot-plants that is intolerant to heat stress and susceptible to diseases. In this study, influence of arbuscular mycorrhizal fungi (AMF); Glomus mosseae (Gm), Gl. Fasciculatum (Gf) ) symbiosis on tolerance to anthracnose caused by Colletotrichum gloeosporioides (Cg) under heat stress condition and the changes in antioxidative ability were investigated using three cyclamen cultivars (‘Eve’, ‘IPMSP9’ and ‘MIC3’). During the production period, temperature of greenhouse and pot soil was recorded and the highest temperature was around 40C. Higher biomass under heat stress was observed for Gm added to the media in ‘IPMSP9’ and ‘MIC3’. Disease incidence and severity of symptoms in non-AMF plots were the highest in ‘IPMSP9’ and lowest in ‘MIC3’. In AMF plots, disease incidence and severity of symptoms were lower than non-AMF plots among all the cultivars, regardless of the AMF species. As for antioxidative ability, superoxide dismutase (SOD) activity and diphenyl-2-picrylhydrazyl (DPPH) radical scavenging activity in shoots and roots showed higher levels in some of the AMF plots after Cg inoculation. Thus, the findings indicate that AMF association has the ability to promote the growth of cyclamen under heat stress condition and could suppress anthracnose in cyclamen production with Gm being most for this purpose. In this case, antioxidative abilities increased under heat stress and pathogen-stressed conditions, so that the tolerance would be associated with such factors.