ISOLATION AND IDENTIFICATION OF PYTHIUM DELIENSE FROM ORANGE ORCHARD IN TUYEN QUANG PROVICE, VIET NAM

Orange plants cultivated in Tuyen Quang province in northern Vietnam exhibited symptoms of brown rot. This study aimed to identify the causal organism responsible for the disease and evaluate its pathogenicity. Morphological characteristics and phylogenetic analysis of the ITS and cox1 gene sequences identified isolates Oo16-VN and Oo29-VN as Pythium deliense. To our knowledge, this is the first report of P. deliense associated with brown rot of oranges, both globally and in Vietnam.