State Key Laboratory of Tree Genetics and Breeding, Institute of Ecological Conservation and Restoration, Chinese Academy of Forestry; Comprehensive Experimental Center in Yellow River Delta of Chinese Academy of Forestry.
Beijing Haidian Kaiwen Academy High School.
J Vis Exp. 2024 Sep 20(211). doi: 10.3791/67290.
Stem canker diseases caused by the pathogen Cytospora chrysosperma (Pers.) Fr.) and Botryosphaeria dothidea (Moug. ex Fr.) Ces. & de Not. are the two major forest diseases in the poplar plantations in China, sometimes which can destroy all the poplar seedlings or severely damage mature poplar forests. Hybrid breeding is the most direct and efficient method of controlling and managing tree diseases. However, assessing disease resistance or selecting disease-resistance clones based on In vitro stem inoculation is inefficient, time-consuming, and expensive, limiting the development of hybrid breeding of poplar stem canker disease. In this study, we proposed an alternative method to assess disease resistance to stem canker pathogens through in vivo leaf inoculation. The test materials used in this method can be on 1-year-old poplar saplings or the annual branches of perennial poplars in the greenhouse or the field. The critical step of this alternative method is the selection of inoculating leaves: the 5-7 newly matured leaves might be the most suitable. The second critical step of the leaf inoculation method is to make wounds on plant leaves through needle pierces, providing sufficient lesions to measure disease severity. For the adequate number of leaves produced in the early stage of poplar breeding, this in vivo leaf inoculation contributes to the rapid, accurate, and large-scale screening of the disease-resistance poplar clones to stem canker pathogens. Moreover, this leaf inoculation method will also serve as an efficient method for screening pathotypes of stem canker disease pathogen C. chrysosperma, B.dothidea, or other poplar stem canker pathogens.
由病原体 Cytospora chrysosperma（Pers.）Fr.）和 Botryosphaeria dothidea（Moug. ex Fr.）Ces. & de Not.引起的溃疡病是中国杨树林地的两种主要森林病害，有时会破坏所有的杨树苗或严重损害成熟的杨树林。杂交育种是控制和管理树木病害最直接、最有效的方法。然而，基于离体茎接种评估疾病抗性或选择抗病无性系的方法效率低、耗时且昂贵，限制了杨树溃疡病的杂交育种的发展。在本研究中，我们提出了一种通过活体叶片接种来评估溃疡病病原体抗性的替代方法。该方法的测试材料可以是温室或田间 1 年生的杨树苗或多年生杨树的一年生枝条。该替代方法的关键步骤是接种叶片的选择：新成熟的 5-7 片叶片可能是最合适的。叶片接种方法的第二个关键步骤是通过针刺在植物叶片上造成伤口，提供足够的损伤来测量疾病严重程度。对于杨树育种早期产生的足够数量的叶片，这种活体叶片接种有助于快速、准确和大规模筛选对溃疡病病原体具有抗性的杨树无性系。此外，这种叶片接种方法也将成为筛选溃疡病病原体 C. chrysosperma、B.dothidea 或其他杨树溃疡病病原体的有效方法。
