丹参根腐病病原菌及其生防菌的筛选

Root Rot Pathogens of Salvia miltiorrhiza and Screening of Biocontrol Bacteria

本研究旨在筛选用于丹参根腐病防治的生物防治菌株。实验以山东省日照市、临沂市、泰安市发病的丹参及健康丹参的根际土为试材。采用组织分离法从发病丹参中分离病原菌,采用稀释涂布法和平板对峙法从根际土中筛选生防菌,利用形态学和16S rRNA进行鉴定,并在离体丹参上进行防效验证。结果表明,从发病丹参上分离出的病原菌RBT-2-1为木贼镰刀菌(Fusarium equiseti),从根际土中筛选出的生防菌i为绿针假单胞菌橙色亚种(Pseudomonas chlororaphis subsp.aurantiaca)。i对TBG-2-1的抑菌率为66.67%,i在离体丹参上对TBG-2-1的防治效果预防组均高于治疗组,且预防组中追加i菌液的防效最好,为44.45%,比预防组中未追加i菌液的处理提高了1.6倍,比治疗组提高了7.0倍。由此可知,i的接种顺序及使用次数会影响对TBG-2-1的防效。本研究为后期大田试验提供参考依据。

To screen the biocontrol bacteria of Salvia miltiorrhiza root rot,the infected S.miltiorrhiza and rhizosphere soil from healthy S.miltiorrhiza in Rizhao,Linyi,and Tai'an cities of Shandong Province were used as test materials.The tissue separation method was used to isolate the root rot pathogen from infected S.miltiorrhiza.The gradient dilution plate method and disk diffusion method were used to screen biocontrol bacteria from rhizosphere soil.Identification was achieved through the use of morphological characteristics and 16S rRNA,and control effect testing was carried out on the detached S.miltiorrhiza.The results showed that the pathogen RBT-2-1 isolated from infected S.miltiorrhiza was Fusarium equiseti,and the biocontrol bacterium i screened from rhizosphere soil was Pseudomonas chloriraphis subsp.aurantiaca.The antibacterial rate of i against TBG-2-1 was 66.67%.The control effect of i against TBG-2-1 on the detached S.miltiorrhiza in the prevention group was higher than in the treatment group.Furthermore,the addition of i in the prevention group resulted in the best control effect,reaching 44.45%.The prevention group of adding i was 1.6 times higher than the prevention group without addition,and 7.0 times higher than the treatment group.It can be concluded that the sequence and frequency of inoculation with i will affect the prevention efficacy of TBG-2-1.This study serves as a guide for future field experiments.