Mycoplasma-like organisms as the causative agent of witches' broom of cedrela (Cedrela toona Roxb.) in Himachal Pradesh, India

摘要

C. toona [Toona ciliata] is an important timber plant growing extensively in Himachal Pradesh, India. Unfortunately, a large number of trees exhibit witches' broom-like disease symptoms in the crown region. The infected plant displays stunted growth, excessive bud sprouting, reduced leaf size and inhibition of flowering. All these symptoms suggested the involvement of phytoplasmas. Histochemical examination of thin stem sections revealed a strong positive reaction with Dienes' stain and the fluorescent dye aniline blue in the phloem elements of infected plants. Application of tetracycline to diseased plants caused remission of disease symptoms. These experiments established the association of phytoplasmas with the disease. Tetracycline treatment of infected plants was an effective remedy.