Patogenicidad de Chrysoporthe cubensis en clones de Eucalyptus grandis y E. urophylla en el sureste de México

Abstract

Eucalyptus grandis S.T. Blake and E. urophylla Hill ex Maiden are the most promissory species for forest plantations in the southeastern of Mexico. Their production potential is threaten by the canker pathogen, Chrysoporthe cubensis (Bruner) Gryzenhout & M.J. Wingf., which affects most of the trees and can cause damage of about 43,6% in E. grandis trees and up to 40% of the merchantable volume of both species. This study was carried out to assess the pathogenicity of C. cubensis in six E. grandis and four E. urophylla clones. Four isolates of C. cubensis were inoculated on young twigs of both eucalyptus clones in laboratory conditions and the highly pathogenic isolate was selected after thirty days. Four plants of each clone were subsequently inoculated in greenhouse conditions with the isolate A3, which was the most virulent, to determine their tolerance to the pathogen after thirteen months. In both trials, lesion length in the bark was measured. Results showed that the four isolates of C. cubensis are capable of causing lesions on young twigs of Eucalyptus clones and significant differences were observed between clones and isolates. All tested clones were susceptible to isolate A3, but exhibited varying levels of tolerance to the attack.