Evaluation of Serological and Molecular Method for Detection of Xylella Fastidiosa Associated with Olive Quick Decline

Sampling was carried out monthly for five months (March to July) on different host plants known to be infected by X. fastidiosa in previous surveys in order to evaluate the efficiency of a patented “sap extraction method” for favoring the detection of X. fastidiosa. Regarding the bacterium isolation, “sap extraction” showed to be more performing than conventional ones for olive, N. oleander and P. myrtifolia. The study confirmed that the best period for the bacterium isolation was from the end of spring to early summer. Regarding the use of Sap extraction for diagnostic purposes, slight differences were related to the type of explants used in ELISA and RT-LAMP. Likely, the surface sterilization of plant material may decrease the concentration of the bacterium in Sap extraction. In ELISA, Sap extraction looks less sensitive and has a slower reaction kinetics compared to conventional extraction method, while RT-LAMP applied with Sap Extraction looks better than conventional ones. Concerning RT-LAMP, the numbers of comparative tests should be increased. From the preliminary results of this study, it would appear that the “sap extraction method” is more effective than the conventional one for the isolation of different fungal species.