First Report for Alternaria sp. Infection of Eucalyptus Globulus in Al-Taif Province at Kingdom of Saudi Arabia

Eucalyptus trees are plants of industrial and medical importance. In this study tumor or canker disease of exotic plantation Eucalyptus globulus trees has been recorded in Al-Taif province - Kingdom of Saudi Arabia . The obvious symptoms of the disease include tumors at leaf mid-rib, stem and petiole along with chlorosis in the leaves. Histological investigation of collected plant samples from infected and healthy ones using hand sectioning technique, revealed complete destruction of vascular tissues and entire hydrolysis of xylem vessels into large cavity, a record not viewed in healthy plant parts. Microbiological investigation of the plant parts leaf, petiole and stem of all samples revealed fungal infection by Alternaria alternata upon inoculation of potato dextrose agar media supplemented with chloramphenicol