Assessment of pear decline prevalence and phytoplasma infection in major commercial orchards of Al-Mafraq, Jordan

Pear decline, associated with ‘Candidatus Phytoplasma pyri’ (16SrX-C), is one of the most destructive phytoplasma diseases of pear worldwide. In 2023, a four month survey was conducted in commercial pear orchards across the Al-Mafraq region, Jordan. Pear decline-like symptoms, including leaf curling, reddening and stunted growth, were observed with a disease incidence ranging from 70% to 95%. A total of 200 symptomatic and 13 asymptomatic samples were collected from pear trees in four locations. Molecular detection using nested PCR with specific primers targeting the phytoplasmas in 16SrX group revealed a 100% infection rate in all tested symptomatic samples. No phytoplasma presence was detected in asymptomatic samples. The results highlight the widespread presence of ‘Ca. P. pyri’ in commercial pear orchards in Al-Mafraq, indicating the need for their further molecular characterization and the development of management strategies to mitigate the disease’s impact.