不同类型油菜根部内生微生物组与黑胫病（Leptosphaeria biglobosa)的交互作用分析

Blackleg is an important disease on oilseed rape . Root infaction by conidial of Leptosphaeria spp can course severe epidemic of blackleg on oilseed rape. Different symptoms were showed on different type of oilseed rape infacted from root which indicated the root endophytic microbial community may play a role in the biological process of root infection. In view of this, the project uses microbiomics technology and plate separation method to explore the dynamics of roots endophytic microbial community before and after the L.biglobosa infection, and narrowed down some key endophytes. The direct interaction mode between the key endophytes and L.biglobosa was identified by the plate isolation. and the interaction mode between key endophytes and rapeseed hosts was identified by monitoring the expression of defense genes in the plants inoculated with key endophytes using Q-PCR technology. These would help to understand the interaction mechanism between oilseed rape and fungal disease from the perspective of ecology.

油菜黑胫病是重要的油菜病害，分生孢子的根部侵染是油菜黑胫病流行的重要途径。不同类型的油菜对于黑胫病的根部侵染呈现出不同的抗性水平。根部内生微生物群落可能是影响油菜黑胫病根部侵染过程的关键生物因素。鉴此，本项目利用微生物组学技术和平板分离法来探讨油菜根部内生微生物群落在油菜黑胫病侵染前后的消长规律，并筛选出起到关键作用的内生菌株，可以丰富油菜内生菌资源。通过平板对峙法明确油菜根部关键内生菌与油菜黑胫病菌之间的直接互作模式，借助Q-PCR技术对关键内生菌接种植物组织防御基因的表达进行监测，明确关键内生菌与油菜寄主的互作模式。有助于从生态学角度认识油菜黑胫病与油菜之间的互作机理，为油菜黑胫病的综合防控提供新的思路。

研究围绕油菜黑胫病根部侵染途径，对三个不同品种，两个不同发育阶段以及两种土壤条件下的油菜根内及根际微生物群落进行了采样观察。利用微生物组学工具分析了其微生物群落的变化，发现根际微生物群落多样性受黑胫病侵染影响不显著，但在物种群落组成上变化明显。其中土壤条件对根际微生物群落的影响较大，不同品种油菜对黑胫病的响应没有显著区别。对处理过的油菜植株进行了取样分离，分离得到细菌单菌落2136个，真菌单菌落180个。将分离得到的菌株与黑胫病菌进行对峙，试验发现假格里朗苍白杆菌（Ochrobactrum pseudogrignonense）B1与解淀粉芽孢杆菌（Bacillus amyloliquefaciens） B3对于油菜黑胫病有拮抗效果。将B1与B3菌液摇陪与油菜黑胫病菌进行了防治接种试验，并于1个月后进行油菜根部转录组分析，结果发现油菜防御功能的基因有8-14个出现转录差异，其中解毒反转运蛋白 DETOXIFICATION 42-like isoform X1等3个基因表达量呈现显著差异。另外，研究还获得了生防菌Canl30，其在蔬菜促生和抗病方面具有开发潜力。