Occurrence of Non-infectious Phyllody Disease of Strawberry in Thailand

Abstract

Strawberries showing phyllody symptom on fruits has been observed in No.50 cultivar grown in northern region of Thailand since 1996. The symptomatic strawberries produce very poor fruit quality and unmarketable. The disease was epidemic in many strawberry growing areas. The abnormality symptom is similar to the green petal disease which caused by phytoplasma. Several methods including electron microscopy, serological methods, and PCR were used to detect phytoplasma in symptomatic strawberries. All methods gave negative results and phytoplasma could not be detected. In addition, the disease was proved not transmitted to healthy strawberry and periwinkle by grafting and dodder transmission. Evidently, this phyllody disease of strawberry is not caused by phytoplasma. It is possibly caused by physiological disorder and is called non-infectious phyllody disease that was previously found in strawberry in Italy.