Seedling Resistance of Interspecific Crosses from Female Eucalyptus urophylla to Bacterial Wilt

In this paper 81 interspecific controlled-pollinated families and 3 open-pollinated families from female Eucalyptus urophylla were inoculated with Pseudomonas solanacearum at seedling stage. Results show that the families differ in disease index and mortality, and the three open pollinated families perform all poor in resistance. Some interspecific resistant families were selected out. In terms of the resistance of interspecific combination, E. tereticornis,E. camaldulensis, E. exserta,E. Leizhou No. 1 and E. pellita are potentially good fathers, but E. grandis, E. grandis urophylla and E. saligna are poor. Catalase activity before and after inoculation was determined which indicated that the increase of catalase activity was of strongly positive relation with the resistance of the families. Increase of catalase activity after inoculation could be an useful assistant index for early selection of eucalypt materials resistant to Pseudomonas solanacearum.