Molecular-based Integrated Identification of Bacterial Blight(Xanthomonas axonopodis pv. dieffenbachiae) in Anthurium and Detection of Latent Infection

Bacterial blight,caused by Xanthomonas axonopodis pv. dieffenbachiae( Xad),is the most destructive disease of anthurium worldwide,and no effective control technique has been developed currently. The comprehensive survey and precise detection of the pathogen is essential for evaluating disease progress and strengthening management to avoid a serious epidemic. In this study,a total of 253 blight-suspected samples of anthurum and other Araceae species were collected across the country,and 166 potential pathogenic bacteria strains were isolated and purified,after combined analysis on the characteristics of morphology,pathogenicity,16 S r DNA sequences and amplicons of Xad-specific SCAR markers. Finally,93 of which were considered as X. axonopodis pv. dieffenbachiae. In addition,by using a nested-PCR in repeated detections,17 out of 21 prevalent anthurium cultivars without blight symptom exhibited latent infection even in young leaves. The results indicated that the anthurium bacterial blight distributed commonly in growing areas in China,and most of the commercial cultivars had no strong resistance.The identification of Xad infection( latent) would be beneficial for the disease forecasting and management improving in anthurium production.