Detection of Powdery Mildew Growth in Hazelnut Plant Using PCR

Abstract

Powdery mildew is a serious disease of economically important hazelnut crop in Turkey. Hazelnut production has been extremely affected by the disease in terms of quality and quantity. The disease is caused by two different fungi, namely Erysiphe corylacearum and Phyllactinia guttata. E. corylacearum has been shown to be the responsible one predominantly for the recent economic damage. The fungi produce a mycelium network on hazelnut plants before they sporulate and visually detected. Early detection of these pathogens is important for management as well as understanding their spread and epidemics. In this study, a PCR assay was developed for the detection of both pathogens from hazelnut plant leaves by targeting their ribosomal DNA genes in their internal transcribed spacer (ITS) regions. Two sets of specific primers were designed for the detection of E. corylacearum and P. guttata at an early stage of infection. As a result of PCR, a specific band of 578 bp was observed. The amplicon sequencing confirmed the presence of only E. corylacearum, but not P. guttata. Therefore, this PCR-based test can identify plants that are infected with powdery mildew before they show any visual signs. From there, the infected plants can be treated or removed before the fungus has a chance to produce spores that infect neighboring plants. These results would help tackle the eradication of powdery mildew.