1. Tomato leaf mold in the midwest Nicholas LeBlanc, Lillian Garber, and Angela Orshinsky Department of Plant Pathology University of Minnesota, Twin Cities MN, USA

2. Motivation for studying tomato leaf mold in the Vegetable Pathology Lab Summer, 2013-2015 Survey of tomato diseases in MN high-tunnels Tomato leaf mold most common disease

3. Tomato leaf mold Symptoms and signs Conducive environment 80-99% humidity Temp > 14 °C (57 °F) Pathogen: Passalora fulva Biotroph

4. Presentation overview 1. Is P. fulva the only fungus associated with tomato leaf mold?

5. Presentation overview 1. Is P. fulva the only fungus associated with tomato leaf mold? 2. Can fungi associated with tomato leaf mold, other than P. fulva, infect tomato plants and cause tomato leaf mold symptoms?

6. Presentation overview 1. Is P. fulva the only fungus associated with tomato leaf mold? 3. Ongoing and future experiments and hypotheses 2. Can fungi associated with tomato leaf mold, other than P. fulva, infect tomato plants and cause tomato leaf mold symptoms?

7. Collection of leaf mold associated fungi Twin Cities MN, USA Angela Orshinsky Lillian Garber

8. Twin Cities MN, USA Angela Orshinsky Lillian Garber Ithaca New York, USA (Chris Smart) Chris Smart Collection of leaf mold associated fungi

9. Twin Cities MN, USA Angela Orshinsky Lillian Garber Ithaca New York, USA (Chris Smart) Chris Smart La Plata, Argentina (Medina et al. (2015) Plant Disease 99 (12): 1732-1737) Collection of leaf mold associated fungi

10. Phylogenetics of fungi associated with tomato leaf mold Neighbor-joining tree from ITS (fungal barcode) DNA sequence data Colored tips are leaf mold isolates coded by geography Black tip labels are reference species

11. Phylogenetics of fungi associated with tomato leaf mold

13. Genus Cladosporium

14. Phylogenetics of fungi associated with tomato leaf mold Genus Cladosporium Tomato leaf mold pathogen P. fulva is distantly related to Cladosporium

15. Do Cladosporium fungi associated with tomato leaf mold infect tomato? 1000X detached leaf assay Detached leaf assay point inoculation Cladosporium spp. Trypan-blue staining 18 dpi

16. 1000X detached leaf assay Detached leaf assay point inoculation Cladosporium spp. Trypan-blue staining 18 dpi Do Cladosporium fungi associated with tomato leaf mold infect tomato?

17. Do fungi associated with tomato leaf mold diagnostic symptoms? Inoculation methods Spray (5 x 10 5 spores/mL) Soil drench of pathogen+PDB Dry spore inoculation with fine brush

18. Do fungi associated with tomato leaf mold diagnostic symptoms? Inoculation methods Spray (5 x 10 5 spores/mL) Soil drench of pathogen+PDB Dry spore inoculation with fine brush

19. Current research: recovery of P. fulva from high-tunnel soil

20. Current research: environmental monitoring Installing data-loggers outside and inside MN high- tunnels to measure soil and atmospheric temperature and humidity.

21. Future experiments: epidemiology and disease control Evaluation of fungicides to control tomato leaf mold in MN high-tunnels Effect of temperature on growth of P. fulva and other tomato leaf mold associated fungi 2°C 10°C 25°C 30°C

22. Conclusions and future questions Cladosporium spp. are consistently associated with tomato leaf mold No strong evidence that they are pathogens, but may infect the plants

23. Conclusions and future questions Cladosporium spp. are consistently associated with tomato leaf mold No strong evidence that they are pathogens, but may infect the plants Are these really signs of the pathogen?

24. Acknowledgements MN Dept. Agriculture Specialty Crop Block Grant Rapid Agricultural Response Fund Cooperating growers in Minnesota University of Minnesota Department of Plant Pathology Chris Smart at Cornell University Angela Orshinsky and the Vegetable Pathology Lab at UMN

25. Phylogenetics of fungi associated with tomato leaf mold Genus Cladosporium C. cladosporioides complex P. fulva isolate NRRL 1671 is now C. halotolerans P. fulva as an outgroup

26. Multi-locus sequence typing of Leaf Mold associated fungi ITS+actin NJ tree of predominant Leaf Mold clade in MN and NY

27. Phylogenetics of fungi associated with tomato leaf mold Genus Cladosporium C. cladosporioides complex