ISHS Acta Horticulturae 821: International Symposium on Tomato in the Tropics
CAN ROOT ENDOPHYTIC FUNGI CONFINE SPREAD OF PEPINO MOSAIC VIRUS IN TOMATO? |
| Authors: | A. Fakhro , S. von Bargen, M. Bandte, C. Büttner, D. Schwarz, P. Franken |
| Keywords: | Piriformospora indica, Pythium aphanidermatum, Pythium oligandrum, induced resistance, defence genes |
| Abstract:
Pepino mosaic virus (PepMV) is nowadays known to infect tomato severely. At the moment the virus can only be controlled by comprehensive disinfection and care in the greenhouse. Therefore, this project aimed to test the fungi as biological agents to confine the disease. Pythium aphanidermatum, Pythium oligandrum, and Piriformospora indica were selected because they are known to either promote plant growth or delay infection and distribution of PepMV, as found after pre-infection with P. aphanidermatum. Tomatoes cv. Hildares were grown in nutrient solution in a greenhouse for 84 days. Plants were inoculated with a suspension of spores and mycelium of the three fungi. Twenty days later, leaves of 50% of the plants were inoculated mechanically with PepMV leave homogenates containing the French-isolate E 397/1. Success of infection was confirmed and quantified with DAS-ELISA. Infection of the three fungi was confirmed by light microscopy. Expression of several genes involved in plant defence mechanisms was analyzed. Analyses of tomato inoculated only with P. indica resulted in a significant enhancement of growth and fruit setting, for the first time shown in nutrient solution. The two other fungi did not affect the growth significantly. However, all fungi promoted the distribution of PepMV in the tomato shoot organs. No correlation was found between gene expression patterns and spread of PepMV. But the defence-related genes selected were always induced significantly when tomato was infected by both P. indica and PepMV. Mechanisms leading to the higher susceptibility of tomatoes against PepMV in the presence of a fungus are not clear and must be investigated in further experiments. | |
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