Link to home

Burkholderia gladioli can inhibit Burkholderia glumae in rice seedlings affected with bacterial panicle blight

Juan Cevallos-Cevallos: Escuela Superior Politecnica del Litoral, ESPOL

<div>Rice is the most consumed crop worldwide and the basis of the diet in many countries but its production is being threatened by the bacterial panicle blight disease (BPB) caused by either <em>Burkholderia glumae</em> or <em>B. gladioli</em>. However, the interaction of both pathogens <em>in planta</em> is still poorly understood. Isolates of <em>B. glumae</em> and <em>B. gladioli</em> were plated on PDA individually or as a combination of both pathogens. Similarly, rice seedlings were inoculated with each pathogen separately or in a 50 % mixture. Inhibition halos were measured in the Petri dishes whereas progression of disease severity was assessed in inoculated and control seedlings. Pathogens were recovered from infected plants in Petri dishes and each colony-forming unit was identified as <em>B. glumae</em> or <em>B. gladioli</em> by PCR using specific primers. Isolates of <em>B. gladioli</em> inhibited the growth of <em>B. glumae</em> <em>in vitro</em>, with average inhibition halos of 29.6 mm. Both pathogens produced similar BPB disease progression but no significant interaction effect was observed in the plants. The recovery levels of both pathogens was similar in seedlings infected with each bacteria individually. However, more than 90 % of the bacteria recovered from symptomatic seedlings infected with the 50 % mixture of both pathogens were identified as <em>B. gladioli</em> and no <em>B. glumae </em>was observed in infected plants during the first three weeks of the disease<em>.</em> Results show the competition of both pathogens rice plants.</div>