Elimination of Aster Yellow Phytoplasma from Dendranthema grandiflorum by Application of Oxytetracycline as a Foliar Spray

Chung, Bong Nam; Choi, Gug Seoun

The Plant Pathology Journal 2002;18(2):93-97.
Published online April 30, 2002.

Elimination of Aster Yellow Phytoplasma from Dendranthema grandiflorum by Application of Oxytetracycline as a Foliar Spray

Bong Nam Chung, Gug Seoun Choi

Abstract

Aster yellows phytoplasma-infected chrysanthemums showing stunt, rosette, and excessive branching were treated with a foliar spray of 400 mg/l oxytetracycline at three-day interval for 1, 2, 3 and 4 months. Two months after the final treatment, new shoots from the recovered chrysanthemums showed the recurrence of the disease symptoms. However, cuttings from chrysanthemums treated with oxytetracycline did not express any phytoplasma infection symptoms for more than 10 months. Also, chrysanthemums dipped in 100 mg/l oxytetracycline solution combined with a foliar spray of 400 mg/l oxytetracycline for 4 weeks showed the same results. Using an electron microscope, ultrathin sections of leaf midribs of chrysanthemum cuttings treated with oxytetracycline for 4 months did not show phytoplasma bodies 10 months after treatment. Nucleic acids from chrysanthemums, which did not express phytoplasma infection symptoms for more than 10 months, did not amplify 16S rRNA gene of phytoplasma by polymerase chain reaction. These results may have implications in the propagation of phytoplasma-free healthy stocks for a wide range of plant species.

Key Words: aster yellow, chrysanthemum, oxytetracycline, phytoplasma, recovery