白粉菌BGP(TG)在不同抗性草地早熟禾叶片上的侵染过程观察

Infection process of Blumeria graminis f. sp. poae BGP(TG) on the leaves of Poa pratensis with different resistance

摘要:

【背景】草地早熟禾(Poa pratensis)白粉病是气传性病害，种植抗病品种是防治白粉病最经济、环保和有效的方法。【目的】明确禾布氏白粉菌BGP(TG)在3个不同抗性草地早熟禾叶片上的侵染过程和乳突在草地早熟禾抗白粉病中起的重要角色。【方法】利用考马斯亮蓝染色结合显微镜观察的方法，对不同抗性的3个草地早熟禾品种进行白粉菌侵染过程观察，统计分生孢子形成次生芽管的速度、吸器和乳突的形成情况，分析白粉菌对不同抗性草地早熟禾侵染过程的差异。【结果】‘探险家’草地早熟禾病症较其他2个品种更为严重，禾布氏白粉菌BGP(TG)侵染不同抗性品种的侵染过程基本一致，但‘探险家’叶片上初生吸器形成早于其他2个品种；接菌1-2 d后，在‘太行’叶表面分生孢子形成5级芽管的速度显著低于‘探险家’和‘黑杰克’；接种1 d后，‘太行’草地早熟禾有效乳突形成率显著高于‘黑杰克’ (P＜0.05)，‘黑杰克’有效乳突形成率显著高于‘探险家’ (P＜0.05)。【结论】明确了白粉菌在草地早熟禾叶片上的侵染过程和乳突在草地早熟禾抵御白粉菌侵入过程中起的重要作用，为草地早熟禾白粉病的预防和防治提供了理论基础和参考。

Abstract:

[Background] Poa pratensis powdery mildew caused by Blumeria graminis f. sp. poae is an airborne disease, and planting resistant species is the most economical, environmentally friendly, and effective method for controlling this disease. [Objective] To observe the infection process of BGP(TG) on the leaves of three P. pratensis species with different resistance and clarify the role of papillae in the resistance of P. pratensis to powdery mildew. [Methods] Coomassie brilliant blue staining was combined with microscopy to observe the infection process of BGP(TG). The rate of secondary germ tube formation and the formation of haustoria and effective papillae in the three species were determined. [Results] The powdery mildew symptoms in ‘Explorer’ were more serious than those in the other two species, and the infection process of BGP(TG) was similar in different species. However, the formation of primary haustoria on the leaves of ‘Explorer’ was earlier than that of the other two species. One- or two-days post inoculation with BGP(TG), the formation of fifth-level germ tubes on the surface of ‘Taihang’ was slower than that of ‘Explorer’ and ‘Black Jack’. One day post inoculation with BGP(TG), more effective papilla was formed on ‘Taihang’ than on ‘Black Jack’, and the effective papilla formation rate on ‘Black Jack’ was higher than that on ‘Explorer’ (P＜0.05). [Conclusion] This study clarifies the infection process of B. graminis f. sp. poae and provides a theoretical basis for the prevention and control of powdery mildew in P. pratensis.