INDUCED RESISTANCE AGAINST PHYTOPHTHORA INFESTANS BY CHEMICAL INDUCERS BION AND BABA IN TOMATO PLANTS
Induced resistance uses the natural resistance in plants and has for a long time been observed in nature. The plants possess many different types of defense mechanisms, for example reacting with necrosis, the formation of lignin phytoalexin and peroxidase activity and hypersensitive (HR) to hinder the penetration of pathogens into plant tissue. In addition to other control measurements during pre-inoculation of pathogens treatments with microbial extracts and chemical inducers like BION and BABA can be used in plant protection. After inducer applications, the physiological activities in the plant will be affected and changed. In this connection a particular task will be attached to the so-called Pathogenesis-Related proteins (PR-proteins) in the plants and will inhibit mycelial growth and lesion formation. This connection can induce different kinds of resistance in plants. In vivo tests with BION showed reductions in necrotic symptoms on leaves of tomatoes caused by Phytophthora infestans and complete inhibitions of symptom expression on the upper younger leaves as compared to the necrotic control plants, similar results were also observed for BABA. However, BABA produced toxic effect on the leaves of the variety Balkonstar, but had no inhibitory effect on the growth of the plant. The prominent outstanding results of this presented work with the 3 Isolates of P. infestans on the tomato varieties Rheinland Ruhm, Yellow Pearshaped and Balkonstar showed that BION had a significant effect in controlling P. infestans. In vitro test showed that BABA with 10,000 ppm and BION with 1000 ppm reduced about 10-15% of the mycelial growth on to V8-juice medium as compared to the control. The results presented furthermore an indication that applications of both BION and BABA weakened the pathogens virulence, which was in correlation with a plant defense mechanism reducing and preventing disease expression. To reduce the use of pesticides which are not environmentally accepted, research should be directed towards use of alternative methods such as application of inducers.
Arıcı, S.E. and Dehne, H.W. (2007). INDUCED RESISTANCE AGAINST PHYTOPHTHORA INFESTANS BY CHEMICAL INDUCERS BION AND BABA IN TOMATO PLANTS. Acta Hortic. 729, 503-507
Lycopersicon esculentum, chemical inducers, Phytophthora infestans, inoculation, mycelial growth