Detecting new emerging viruses and phytoplasmas of grapevine in Lebanon for developing future adaptation strategies to climate change.

Global warming and environmental changes could lead to the emergence of unknown viruses and phytoplasmas, posing a significant threat to viticulture and the wine industry. Consequently, impacting farmers' incomes, the environment, national economies, and international trade. A survey was conducted in 52 commercial vineyards in Lebanon during late summer of 2020. RT-PCR and PCR assays were performed on 252 grapevine samples and revealed prevalent single infections of Grapevine GeminiVirus A (GGVA) (9.27%) and Grapevine Garan Dmak Virus (GGDV) (12.7%). Sequence analyses revealed that the Lebanese isolates of GGVA (PQ562408-PQ562417) and GGDV (PV404211-PV404217) were 100% identical with reference sequences in the GenBank. GGDV was detected in both Table (9.27%) and wine (17.82%) varieties, followed by GGVA (9.5%), more prevalent in table grapes (11.25%) than in wine varieties (6.93%). Candidatus Phytoplasma solani was encountered in 8 samples and their sequence analysis (PQ533202-PQ533207) revealed their identity with reference samples in the GenBank. A new putative subgroup of the 16Sr group XII (LebB1 isolate) was discovered in one of the Lebanese samples, warranting further studies. This study is the first report of GGVA and GGDV in Lebanon, demonstrating the presence of emerging diseases in Lebanon and suggesting the need for sustainable prevention and treatment strategies at both national and regional levels.