Novel tetraplex qPCR assays for simultaneous detection and identification of Xylella fastidiosa subspecies in plant tissues

Dupas Enora; Briand Martial; Jacques Marie-Agnès; Cesbron Sophie

plants by tetraplex qPCR assays 358 Ten plant samples from Corsica, France (Table 6 ) and ten samples from inoculated plants (Table 7) 359 were tested using the tetraplex set n°1. Our tetraplex qPCR assay was able to detect the bacterium in 360 samples declared contaminated with Harper's qPCR assay up to Ct =34.97. However, this LOD was 361 variable depending on the matrices (Table 7) . While the bacterium was detected at the subspecies level 362 with one or the other primer and probe combinations in eight environmental plant samples, the XF 363 primers and probe was less efficient and allowed the detection in only five samples ( In this context, on the basis of a large dataset of in-house and publicly available genome sequences of 384