尾叶桉作母本的种间控制授粉家系苗期抗青枯病研究

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

对８１个以尾叶桉为母本的种间控制授粉家系和３个母本的自由授粉家系进行苗期青枯病菌接种试验表明，接种后母本家系抗病性都较差，种间控制授粉家系间发病指数和死亡率有差异，初步筛选出１个特抗家系和４９个抗性家系。以家系抗病性评价父本树种，细叶桉、赤桉、窿缘桉、雷林一号桉和粗皮桉选育潜力较好，巨桉、巨尾桉和柳桉则较差。对抗性、易感和高感抗病水平各３个种间控制授粉家系进行接种前和接种后过氧化氢酶活性测定表明，家系苗期青枯病抗性与接种前的酶活性相关不显著，但与接种后酶活性上升的幅度呈强正相关，抗性家系在接种病菌后酶活性上升幅度最大，易感家系较小，而高感家系则更小。苗期接种青枯病菌后，杂种桉过氧化氢酶活性上升的幅度可作为早期抗病选育的一个重要的辅助依据。

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.