Lasiodiplodia theobromae Associated with Gummosis in Eucalyptus spp in the Sudan

【摘要】：正The present study describes the finding that the fungus Lasiodiplodia theobromae.is the causal agent of gummosis of Eucalyptus citriodora and Eucalyptus camaldulensis in the State of Southern Kordofan.Eculyptus plantations in this area were found to suffer from gummosis disease showing symptoms of gum exudation from cracks that occur naturally about 50cm above the base of most tree trunks.Pathogenicity tests confirmed that the fungus was the causal agent of gummosis.A wound was made at the base of each tree trunk similar to the cracks that occur in the field.The wounds were inoculated with the fungus that grew vigorously on the inoculated sites, followed with copious gumming in some inoculated trees reproducing the same symptoms observed in the field.The infection in this case was localized only at the lower parts of the trunks where the cracks occurred. The other parts of the tree were not affected.The fungus was isolated from the bark,wood and contaminated gum with the fungus on PDA media.The fungus was re-isolated from the inoculated plants.L.theobromae was also isolated from old eucalyptus trees established in other parts of the country.