Jebraeil Bahmani 1, Nader Hasanzadeh 1, Maryam Ghayeb Zamharir 2 and Behrouz Harighi 3
1 Department of Plant Protection, Faculty of Agricultural Science and Food Industries, Science and Research Branch, Islamic Azad University, Tehran, Iran
2 Plant Diseases Department, Agricultural Research, Education and Extension Organization (AREEO), Iranian Research Institute of Plant Protection, PO Box 19395-1454, Tehran, Iran
3 Department of Plant Protection, Faculty of Agriculture, University of Kurdistan, Sanandaj, Iran
Bahmani, J., Hasanzadeh, N., Zamharir, M. G. & Harighi, B. (2026). Detection and phylogenic relationships of Xylella fastidiosa strains from different host plants. Bulg. J. Agric. Sci., 32(2), 325–334
This study aimed to examine and analyze the distribution and phylogenetic relationships of the Xylella fastidiosa strain, a Gram-negative bacterium that impacts plant xylem and is responsible for various diseases in multiple plant hosts. Samples were collected from various plant hosts, including grapevines, pistachios, almonds, apples, pears, elms, cherries, and citrus fruits, across 12 provinces in Iran from 2019 to 2022. Disease incidence was detected in grapevine, pistachio, and almond orchards across six provinces, including Kerman, Yazd, Semnan, Chaharmahal and Bakhtiari, West Azarbaijan, and Qazvin. Tracking and diagnosis of the disease in plant extracts were carried out by ELISA and PCR methods using RST31/33 primer. The efficiency of conventional PCR in disease diagnosis was found to be less than 1%. In contrast, a nested PCR method using the ALSC491-F/ALSC491-R primer, which targets a smaller portion of the RNA polymerase sigma-70 factor gene, demonstrated 55% effectiveness in detecting DNA extraction from plants. Additionally, the common FD2/RP1 and specific XF1-XF6 primers were used to amplify the 16S rDNA gene in a limited number of samples. Our results from nested PCR analysis detected X. fastidiosa as the causative agent of pistachio and grapevine Pierce disease. Furthermore, X. fastidiosa subsp. fastidiosa infection was detected in almond and pistachio hosts.