Abstract:
Objective The pathogen that caused the blueberry branch blight in Sanming, Fujian was identified.
Method Microbes were isolated and purified from the blueberry branches showing anthracnose symptoms collected from the infected area. Pathogenicity of the isolates was tested by needle injection on the plant and verified by the Koch's method. Pathogen taxonomy was determined by morphological observations and molecular technology.
Result Strain KW1-4 was isolated from the diseased tissue and inoculated onto healthy blueberry branches to show on the inoculation site dry spots same as what produced by the strain from the infected plants. The white to gray, round colonies of KW1-4 had two types of conidia. The alpha conidia were elliptical or spindle in shape and 4.77-7.63 μm × 1.55-2.71 μm in size with two distinct oil globules, while the linear beta conidia sized 11.95-19.65 μm × 1.05-1.94 μm with no oil globule. The 3 fragments of the genes, ITS, TEF1-ɑ, and β-tubulin, were used to construct the phylogenetic tree that showed KW1-4 to cluster with Diaporthe australiana in a same branch, which agreed with the morphological characteristics.
Conclusion It was determinedD. australiana to be the pathogen that caused the blight on blueberry bushes in Sanming. The identification paved the way for the disease control.