分离菌株DT-08C的鉴定及其除草活性和对作物的安全性

Identification, herbicidal activity, and selectivity of Fusarium tricinctum DT-08C

摘要:

【背景】猪殃殃为作物田的主要恶性杂草之一，目前的防除仍以化学方法为主，对人体和环境造成严重危害。微生物除草剂具有靶标性强、对环境安全等优点，对发展新型农业现代化具有重要的现实意义。【目的】筛选无污染、无危害、强除草的生防菌株，为微生物除草剂提供新的菌种资源。【方法】通过组织分离法分离纯化菌株，采用孢子悬浮液测定菌株除草活性和安全性，运用核糖体内转录间隔区(internal transcribed spacer, ITS)和转录延伸因子(EF-1α, EF-1/EF-2)基因鉴定，并通过MEGA 7.0软件构建系统发育树，最后通过菌落直径和菌丝干重结合血球记数法分析菌株适宜生长和产孢的环境条件。【结果】经分离纯化筛选获得一株菌，命名为DT-08C。经形态学特征和rDNA ITS序列分析，分离菌株DT-08C鉴定为芍药镰刀菌(Fusarium paeoniae)，命名为Fusarium paeoniae DT-08C。该分离菌株对猪殃殃的致病率达到47.22%-93.93%，对蚕豆、豌豆、玉米、白菜、番茄、黄瓜和辣椒安全。最适菌落生长和产孢的培养基分别为PSA和燕麦片培养基。【结论】菌株DT-08C对猪殃殃的致病性强，对蚕豆、豌豆、玉米、白菜、番茄、黄瓜和辣椒等作物安全，对环境的适应性较广，属于F. paeoniae。上述结果为下一步田间应用提供了菌株资源和试验基础。

Abstract:

[Background] Galium spurium, one of the main noxious weeds in crop fields, is mainly controlled by chemicals, which causes serious harm to the human body and the environment. Microbial herbicides with precise targets and environmental safety have practical significance for agricultural modernization. [Objective] To screen out the non-polluting and harmless strains with strong weed-controlling activities and provide new strain resources for the development of microbial herbicides. [Methods] The strains were isolated and purified by tissue culture method. The herbicidal activity and selectivity of the isolate were determined by the spore suspension method. Internal transcribed spacer (ITS) and EF-1/EF-2 gene sequencing was used to identify the isolate. The phylogenetic tree was constructed in MEGA 7.0 to reveal the phylogenetic relationship of the strain. Finally, the environmental conditions suitable for growth and sporulation of the strain were analyzed based on colony diameter and mycelial dry weight combined with blood cell counting. [Results] A strain DT-08C was isolated and identified as Fusarium paeoniae. The incidence rate of DT-08C infection in G. spurium reached 47.22%–93.93%, and the strain was safe to broad bean, pea, maize, Chinese cabbage, tomato, cucumber, and pepper. The optimum media for colony growth and sporulation of DT-08C was PSA and OA, respectively. [Conclusion] F. paeoniae DT-08C is highly pathogenic to G. spurium but safe to broad bean, pea, maize, Chinese cabbage, tomato, cucumber, and pepper, and it has wide adaptability to the environment. The results provide strain resources for the further field application.