Investigation of the Spread of Bacterial Wheat Leaf Blight Caused by Pathotypes of Pseudomonas syringaein Some Wheat Growing Areas in Syria
Authors:   Faculty of Agriculture Engineering, University of Aleppo, Syria, & General Commission for Scientific Agricultural Research (GCSAR), Syria, Abo Bakr Abed , Khatib Fateh ,   Faculty of Agriculture Engineering, University of Aleppo, Syria, Kassem Mohamad ,   Faculty of Agriculture Engineering, University of Aleppo, Syria, Kumari Safaa G. ,   International Center for Agricultural Research in the Dry Areas (ICARDA), Terbol Station, Zahle, Lebanon,   General Commission for Scientific Agricultural Research (GCSAR), Syria, Hussein Naim ,   General Commission for Scientific Agricultural Research (GCSAR), Syria, Asaad  ,   General Commission for Scientific Agricultural Research (GCSAR), Syria
Published: September 2024

Abo Bakr, A., F. Khatib, M. Kassem, S.G. Kumari, N. Husien and N. Asaad. 2024. Investigation of the Spread of Bacterial Wheat Leaf Blight Caused by Pathotypes of Pseudomonas syringaein Some Wheat Growing Areas in Syria. Arab Journal of Plant Protection, 42(3): 291-298. https://doi.org/10.22268/AJPP-001257 Wheat is one of the most important cereal crops grown globally, which is affected by several biotic and abiotic stresses, especially in conjunction with the climatic changes that have been evident in the last decade, and among these stresses is the bacterial wheat leaf blight disease caused by the bacteria Pseudomonas syringae pv. syringae. The importance and danger of this bacterium is due to its ability to be transmitted by seed, as it negatively affects the quality of grain and the weight of one thousand grains. The study aimed to investigate the spread of bacterial wheat leaf blight caused by P. syringae and its pathotypes in the main wheat growing areas in Syria (Aleppo, Hama, Homs, Tartous and Latakia governorates) during 2022. The results obtained showed that bacterial wheat leaf blight disease was observed in 42 fields out of 59 fields surveyed (71.2%). The lowest incidence (50%) was recorded in Latakia with severity of less than 2, and highest incidence (77.8%) was recorded in Aleppo governorate with severity of 4 based on a 0-5 scale. Symptoms of bacterial wheat leaf blight was observed in all fields, which began as water-soacked leaf spots, and then turned into greenish-gray necrosis and finally a straw color. Symptoms of blackishbrown color nodes were observed only in 4 fields in Aleppo and Tartous governorates, it could be caused by the pathotype P. s. pv. japonica. In addition, the bases of wheat chaffs showed blackish-brown watery spots in 6 fields. In Aleppo and Tartous governorates these symptoms were identical to those typical of the pathotype P. s. pv. atrofaciens. Characteristics of 156 isolates, LOPAT tests and fluorescence on King B medium indicated that these isolates belong to the genus Pseudomonas, representing 87.7% of the total number of isolates, whereas 26 isolates (14.3%) were negative for Levan and fluorescence tests and their characteristics indicated that they belong to the genus Xanthomonas. Keywords: Wheat, bacterial wheat leaf blight, P. syringae, pathotypes, Syria