Detection of Russian olive witches’-broom disease and its insect vector in Northwestern Iran

Abstract

Recently, Russian olive trees showing witches'-broom and little leaf symptoms have been widely observed in northwestern and central Iran. Polymerase chain reaction (PCR) and nested PCR assays using phytoplasma universal primer pairs confirmed phytoplasma symptomatic infection of trees. Sequence analyses showed that 'Candidatus Phytoplasma asteris' was the causal agent of the disease in these regions. However, RFLP results using restriction enzymes HpaII, EcoRI, HinfI and AluI indicated that the collected isolates in these regions are genetically different. In addition, leafhopper Macropsis infuscata was recognized as a possible insect vector of the disease for the first time.

Characterization of ‘<em>Ca</em>. Phytoplasma asteris’, ‘<em>Ca</em>. Phytoplasma australiense’ and ‘<em>Ca</em>. Phytoplasma mali’ Associated with Russian Olive Witches’-Broom Disease in Iran Using Next-Generation Sequencing

“…In previous studies, the 'Ca. Phytoplasma asteris' was characterized as the causal agent of Russian olive witches 'broom disease in Iran [3,15]. However, MetaPhlAn2 analysis suggested that, in addition to 'Ca.…”

“…Later, the 'Ca. Phytoplasma asteris' was recognized, associated with the infected trees [3], and then the genome of Iranian 'Ca. Phytoplasma asteris' was obtained using NGS analysis [15].…”

“…However, it may be prevalent in other areas of the country. It was previously reported that the Russian olive witches'-broom disease is caused by 'Candidatus Phytoplasma asteris' [3]. It was later revealed that the infected trees are a powerful source of phytoplasma transmission to other plants, especially stone fruits [4].…”

“…So far, no insect has been reported as a natural vector of the disease. However, leafhopper Macropsis infuscata (Hemiptera: Cicadellidae) was previously collected on infected trees and could be a potential vector of the disease [3].…”