|DI GIAMBATTISTA, GIUSEPPE|
Submitted to: Plant Pathology
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: 8/3/2007
Publication Date: 4/1/2008
Citation: Inman, A., Magnus, H.A., Riccioni, L., Hughes, K., Coates, M., Barnes, A., Barton, V., Sansford, C.E., Valvassori, M., Di Giambattista, G., Port-Puglia, A., Razzaghian, J., Peterson, G.L. 2008. Survival of Tilletia indica teliospores under European soil conditions. Plant Pathology. 57(2):290-300.
Interpretive Summary: Karnal bunt of wheat is a disease of regulatory significance to the European Union, where the disease has not yet been reported. The disease is caused by the fungal pathogen, Tilletia indica whose primary mechanism for long distance spread are through its rugged teliospore which can be introduced to new areas via contaminated wheat seed. A study was conducted to determine how long teliospores could survive if subjected to select European soils and climate conditions. In Norway, the United Kingdom and Italy, replicate samples of soil contaminated with teliospores of T. indica were buried outside at each location, under containment, but exposed to natural rainfall and temperature fluctuations. Samples were removed annually and tested for viability. Results showed that teliospores survived at all three sites at all the 1-3 year periods studied. At each site, there was no evidence of a marked decline in teliospore recovery between sampling years, The conclusion was that teliospores of T. indica can survive for at least three years in European soils and diverse environments. This long-term potential for survival under European conditions in part supports the potential for T. indica to establish in Europe.
Technical Abstract: As part of a 3-year EU-funded project developing a Pest Risk Analysis (PRA) for Tilletia indica for Europe, teliospore survival studies were done outside under quarantine containment at three European sites (Norway, UK, and Italy). At each site, experiments were set up in three consecutive years (Experiments 1, 2 & 3) to determine teliospore survival over time (1–3 years) at 5, 10 and 20 cm depths. Experiments were sampled annually and survival assessed in relation to teliospore recovery and to germination at recovery (T0) and 3-months after recovery in case of burial-induced dormancy (T3). Teliospores survived at all three sites at all depths over all the 1'3 year periods studied. At each site, there was no evidence of a marked decline in teliospore recovery between sampling years, except in one set of years in one Norwegian experiment. There was no consistent effect of depth on recovery. In general there was little evidence for a marked decline in teliospore germination between sampling years. There was some evidence of a decrease in germination with increasing depth in the UK, and for some time-depth interactions. After 3-years’ incubation (Experiment 1), mean teliospore recovery and mean germination were: for the UK, 61% recovery and 31% (33%) germination for T0 (and T3); for Italy, 30% recovery and 36% (29%) germination; and for Norway, 12% recovery and 19% (49%) germination. Germination for laboratory controls ranged from 20–59% (UK), 18–41% (Italy) and 28–59% (Norway). There was no evidence for burial-induced dormancy except in Norway. Teliospores of T. indica can survive for at least three years in European soils. This long-term potential for survival under European conditions in part supports the potential for T. indica to establish in Europe.