Phytoplasma diseases in Korea

A total of 71 diseases of more than 62 plant species have been reported associated with phytoplasmas in Korea. Among six identified 16Sr groups of phytoplasmas, aster yellows phytoplasmas are presently prevalent group associated with more than 30 plant diseases in the country. Jujube witches' broom, paulownia witches' broom, and mulberry dwarf diseases are the major phytoplasma threats causing serious economic losses every year. Seven species of the genus “Candidatus Phytoplasma,” namely “Ca. P. asteris,” “Ca. P. castaneae,” “Ca. P. pruni,” “Ca. P. solani,” “Ca. P. trifolii,” “Ca. P. ulmi,” and “Ca. P. ziziphi” have been identified in Korea as the disease causative agents. The phytoplasma diseases are distributed in various regions of the country, and most of them were detected in Gyeongbuk and Jeonbuk provinces. At least five insect vectors including Halyomorpha halys, Hishimonus sellatus, Macrosteles striifrons, Nesidiocoris tenuis, and Ophiola flavopicta were reported as putative phytoplasma vectors. This chapter summarizes phytoplasma diseases in Korea, with specific emphasis on the occurrence, identified “Ca. Phytoplasma” species, their host plants, and their putative natural vectors.