First report of ‘Candidatus Phytoplasma pyri’ and ‘Candidatus Phytoplasma phoenicium’ in Jordan
During field surveys conducted in September-October 2021 in North-Western Jordan (Amman and Ajloun governorates), ‘Candidatus Phytoplasma pyri’ (associated with pear decline, EPPO A2 List) was detected for the first time in symptomatic pear (Pyrus communis) trees. The psyllid Cacopsylla bidens (Homoptera: Psyllidae) was abundant in pear trees and also tested positive for ‘Ca P. pyri’, suggesting that this species could act as a vector of ‘Ca. P. pyri’ in Jordan. In addition, ‘Ca. Phytoplasma solani’ (EPPO A2 List), ‘Ca. P. aurantifolia’ (EU A1 quarantine pest) and ‘Ca. P. omanense’ were also detected. A phytoplasma-associated disease causing leaf yellowing and scorch on apple trees (Malus domestica) is also reported for the first time in Jordan. ‘Ca. P. solani’ and ‘Ca. P. omanense’ were detected in symptomatic apple samples.
In another study conducted between October 2020 and January-2021 in North-Western Jordan (Irbid and Ajloun governorates) phytoplasma-like symptoms were observed in almond trees (Prunus dulcis): early flowering along with evergreen pattern; witches’ broom, yellowing and dieback; slim leaf and leaf rolling; stem fasciation. Phytoplasmas were detected in 30 of 140 samples collected from symptomatic almond trees. Seven species were identified: ‘Ca. Phytoplasma asteris’ ‘Ca. P. aurantifolia’, ‘Ca. P. omanense’, ‘Ca. P. phoenicium’ (EPPO A1 List), ‘Ca. P. pyri’, ‘Ca. P. solani’, and ‘Ca. P. ulmi’. This is the first report of ‘Ca. P. phoenicium’ in Jordan, and the first report of ‘Ca. Phytoplasma pyri’, ‘Ca. P. omanense’, and ‘Ca. P. ulmi’ on almond worldwide.
The situation of ‘Candidatus Phytoplasma pyri’ in Jordan can be described as follows: Present, not widely distributed.
The situation of ‘Candidatus Phytoplasma phoenicium’ in Jordan can be described as follows: Present, not widely distributed.
Sources
Alloush AH, Bianco PA, Busato E, AlMahasneh A, Alma A, Tedeschi R, Quaglino F (2023) Association of seven ‘Candidatus Phytoplasma’ species to an almond disease complex in Jordan, and preliminary information on their putative insect vectors. Crop Protection 164, 106147.
Alloush AH, Bianco PA, Alma A, Tedeschi R, Quaglino F (2024) Phytoplasma identification in pome fruit trees and Cacopsylla bidens (Hemiptera: Psyllidae) in Jordan. European Journal of Plant Pathology 169(1), 65-71