Monocycle components of fig rust comparing in vivo and ex vivo methodology

The fig rust (Cerotelium fici) is the upmost important disease in fig but there are few studies on the effect of temperature and wetness period on the pathogen and on the disease. To improve the epidemiological knowledge of this pathosystem the germination of urediniospores and monocycle components were studied: incubation period (IP), latent period (LP) and number of pustules/leaf area, comparing ex vivo and in vivo methodology. For germination, temperatures tested ranged from 15 to 32 °C, with wetness periods of 6, 12 and 24 h, under continuous dark. The comparative study of the monocycle of the disease tested inoculations on leaf discs (ex vivo) and on plants (in vivo) with temperature ranging from 15 to 32 °C and 12 h/12 h light/dark, assessing the number of pustules of the first cycle of infection. Uredinospores germination had the optimal temperature from 25.8 to 28.3 °C increasing with wetness period. The shortest IP and LP were at temperature of 25.6 and 25.1 °C in the leaf discs methodology and 23.7 to 24.9 °C in the leaves on plants methodology. The estimation of the optimal temperature for number of pustules were similar between methods, ex vivo was 23.9 °C and in vivo was 22.9 °C. Similar results were obtained in both methodologies tested. We provide epidemiology bases of fig rust monocycle and we validated ex vivo methodology for this pathosystem; the methodology used is easier, cheaper and less time consuming when comparing to the use of in vivo essays.