Responses of Rice Varieties to the Pathogenesis of Burkholderia glumae Collected from Different Regions of Thailand under Screenhouse Conditions

Abstract

The bacterial pathogen, Burkholderia glumae, can cause severe damage in rice in many countries. The B. glumae disease causes rotting seedlings, rotting leaf sheaths, rotting seeds, burning ears, and significant yield loss. The B. glumae has multiple isolates, each responding differently to each rice line/variety. Thus, the responses of different rice lines/varieties to the bacteria can be used to classify the bacterial groups. This study aims to assess the response of rice lines/varieties to the pathogenicity of B. glumae in greenhouse conditions. The samples of B. glumae were collected from rice fields in 41 districts in 10 provinces in the central, northern, and northeastern regions of Thailand. Thirty-eight isolates of B. glumae were found. Twenty-six isolates were selected and grouped according to their ability to cause disease in 20 rice lines/varieties. The inoculation procedure was done by injecting suspended B. glumae cells (1 x 10⁸ CFU/mL, O.D.₆₀₀ = 0.2) into leaf sheaths of the 45-day-old rice planted in greenhouses to assess their response to disease. The phylogenetic tree was also analyzed using the Bay-Curtis method to group the B. glumae. The results from the analysis can classify the B. glumae into a total of four groups. The B. glumae isolates from Buriram province are the most diverse and were classified into three groups, followed by the isolates from Phrae and Roi Et provinces, which were each classified into two groups.