V M Srinivasan, M Daniel Jebaraj and A S Krishnamoorthy
Department of Plant Pathology, Tamil Nadu Agricultural University, Coimbatore 641 003, India.
Received on 02 September 2016 and accepted on 03 October 2016
Stimulation of resistance by the activity of defense enzymes viz., peroxidase, polyphenol oxidase, catalase and superoxide dismutase up on treatment with azoxystrobin and chaetoglobosin was studied in this experiment. The potato plants inoculated with Phytophthora infestans showed various levels of peroxidase activity with respect to the treatments. The maximum increase of peroxidase activity (0.954) was noted in combined application of azoxystrobin (Willowood) with chaetoglobosin at 0.2 per cent concentration. The individual application of azoxystrobin (0.908), chaetoglobosin (0.711) and metalaxyl (0.702) was also increased the peroxidase activity to a significant level when compared to inoculated (0.327) and uninoculated (0.259) control. The highest (PPO) polyphenol oxidase (0.898) activity was noticed when combined application of azoxystrobin and chaetoglobosin biomolecule. The same combination also showed the maximum induction of catalase (1.042). Combination of azoxystrobin with metalaxyl was recorded the second highest increase (0.783) of PPO. The individual application of azoxystrobin (0.725) chaetoglobosin (0.719) and metalaxyl (0.653) also increased the PPO activity to a significant level when compared to inoculated (0.301) and uninoculated (0.193) control. In the case of superoxide dismutase, the highest (8.01) activity was recorded in combination of azoxystrobin with metalaxyl. The combination of azoxystrobin with chaetoglobosin also recorded the considerable increase in SOD activity (7.72) which is on par with the best treatment.
Azoxystrobin. Chaetoglobosin, Resistance, Enzymes.