Greenhouse experiments by Plant Research International, part of Wageningen UR, show that the presence of the Pseudomonas putida isolate P9 in two late potato varieties infected by P. infestans (the cause of potato blight) leads to a 45 percent delay in the disease’s progress. In the long term this opens up the possibility of deploying this antagonistic micro-organism as an extra component in the integrated control of potato blight.
Scientists at PRI studied the effects of P9 on the potato plant itself and on the presence of natural micro-organisms in the plant, so-called endophytes. P9’s capability to enter the plant was researched in greenhouse experiments. Various microbiological technologies were used to identify P9 in the plant.
Research showed that P9 enters the plant and then settles there permanently. The so-called competent endophyte lives within the plant and interacts with its host and other micro-organisms present. The bacterial compound changed as soon as P9 settled, which meant that the presence of P9 could have made the plant more resistant, and thus more capable of combating diseases and pests. This indeed turned out to be the case - two late potato varieties became more resistant to potato blight.
The research results also throw new light on biological disease and pest control using micro-organisms. Endophytes possibly fight pathogens indirectly by changing the microbiological environment within the plant, unlike most common biological pesticides. This change may enhance the resistance of the plant itself and, as a single application would suffice, could result in a more sustainable mechanism for controlling diseases and pests. The potency of endophytes in integrated disease and pest control is currently being researched further in practical tests.
The research results are based on knowledge based research (Sustainable Agriculture) and the policy-supporting research (Biological Agriculture) performed by Wageningen UR on assignment from the Dutch Ministry of Agriculture, Nature and Food Quality.
» Go to www.kennisonline.wur.nl (in Dutch)