Culture Medium Based on Tomato Leaves for Abundant Production of Conidia from Septoria lycopersici

Aims: This study aimed to perform further experiments about the massive production of spores in alternative culture medium based on tomato leaves with different recipes to foment artificial inoculation for scientific purposes.

Study Design: The experiments were performed in completely randomized designed with three replicates.

Place and Duration of Study: The study was conducted on the Caçador experimental station of the Agricultural Research and Rural Extension Enterprise of Santa Catarina (EPAGRI) from May to November 2018.

Methodology: The study tests 13 amounts of tomato leaves to choose the concentration which better improve the conidia production within two weeks of incubation at 25ºC and photoperiod of 12 h. After the incubation period, the number of spores was counted in a Neubauer chamber. The statistical analysis were performed with Scott-Knot (P<.05). Once the more appropriate quantity of leaves was determined, the conidia production on different media was compared using PDA, King B, NDA, tomato extract, PMA and tomato leaf extract medium incubated at the same conditions as previously described. The amount of conidia produced in tomato leaf extract medium was then compared with those produced in PDA (considered a standard medium for fungus cultivation). After the incubation period, the number of spores was counted in a Neubauer chamber. The statistical analysis was performed with Tukey test (P < .05). Experiments were performed in a completely randomized design with three replicates.

Results: Results from analysis of variance indicated that quantities superior to 13 g per 100 mL rises the amount of conidia produced within two weeks from incubation at 25ºC and photoperiod of 12 h. In addition, all culture media tested supported the mycelial growth, but the production of cirrus was only evident when tomato leaves were used as the main component of the culture medium. Comparatively with the standard medium PDA, the tomato leaf extract medium is more appropriate for experiments dealing with Septoria lycopersici sporulation.

Conclusion: The culture medium based on fresh tomato leaves can foment a large production of cirrus of Septoria lycopersici, reason why it better than the standard medium PDA for research based on septoria leaf spot.