Isolation protocol trials for grapevine bacteriosis (Pierce's disease) agent <i>Xylella fastidiosa</i> Wells et al. during research monitoring of the Republic of Crimea

Abstract

Xylella fastidiosa Wells et al. causes grapevine bacteriosis and is among most hazardous malicious bacterial phytopathogens affecting a wide variety of important crops and ornamental plants. The agent colonises plant xylem and transmits with insects feeding on xylem sap. The insect vectors of X. fastidiosa belong to the order Hemiptera, suborder Auchenorrhyncha, families Cicadellidae, Cercopidae, Aphrophoridae and Cicadidae. A phytosanitary control survey conducted by the All-Russian Research Institute for Plant Quarantine in 2014 identified a high risk of X. fastidiosa introduction and adaptation in the Russian Federation. The Crimean Peninsula is a potential introduction area of the Pierce’s disease agent due to suitable climatic conditions, the ample availability of major host plants, as well as insect vectors. During a research monitoring in 2018-2020, the Institute assessed the phytosanitary status of the Crimean territory. The survey sampled vegetative parts of grapevines, stone fruits (peach, cherry, plum, merry, almond), selected essential-oil and ornamental shrubs and trees. Diagnostic procedures were performed in accordance with the international standards. A three-year phytosanitary survey of the Crimean plantations revealed no presence of X. fastidiosa. Two protocols of sample preparation and DNA extraction from various substrates have been tested. A real-time PCR-based protocol was proved highly specific for zero false positive and nonspecific rates.