黑胫病菌（Leptosphaeria biglobosa）在油菜叶片和茎中的侵染过程观察

为明确黑胫病菌（Leptosphaeria biglobosa）在甘蓝型油菜叶片和茎中的侵染及扩展过程，利用绿色荧光蛋 白（GFP）标记的黑胫病菌株接菌油菜叶片，利用激光共聚焦显微镜观察菌株在油菜叶片和茎中的侵染过程。结果 表明，接种油菜叶片7 h后，分生孢子萌发并长出芽管；17 h后，芽管侵入气孔；24 h后，分生孢子全部萌发；36 h后萌 发的芽管形成菌丝；120 h后，菌丝在叶片表皮细胞间隙蔓延，并侵入叶肉细胞。13 d后，菌丝侵入茎部皮层组织； 15 d后，菌丝在皮层细胞间隙蔓延，并侵染至茎表皮；21 d后，菌丝侵染至维管组织；23 d后，菌丝侵染至茎韧皮部； 25 d后，茎导管被侵染，并向木质部扩展。本研究发现的L. biglobosa 在油菜叶片和茎中的侵染过程，可为油菜与黑 胫病菌互作的研究、黑胫病致病机理及防治提供参考。

Observation on the infection process of Leptosphaeria biglobosa in the leaves and stems of rapeseed

In order to clarify the infection and expansion process of Leptosphaeria biglobosa in rapeseed(Brassica npaus), pathogen infection process was observed in tissue after leaves inoculation by green fluorescent protein(GFP) labeled L. biglobosa. Results showed that conidia germination was observed after 7 h inoculation. After 17 h,germ tube came into stomata, and after 24 h, all conidium germinated. After 36 h, the germ tube formed into hyphae.After 120 h, hyphae spread in leaf epidermal intercellular, and invaded mesophyll cells, then the hyphae continued to infect and extent into leaf, which formed large area disease spot. After 13 d, the hyphae invaded cortical meristem, and after 15 d, it spread to intercellular in cortex, and infected stem epidermis. After 21 d, hyphae spread to vascular tissues. After 23 d, hyphae spread to stem phloem, and after 25 d, hyphae invaded stem catheter, and expanded to the xylem. By tracking L. biglobosa infection process in leaves and stems, it provided a reference basis for research of the interaction between rapeseed and L. biglobosa, and also a reference to pathogenesis mechanism and control of L. biglobosa.