云烟121健康与感黑胫病烟株根系及根际土壤丛枝菌根真菌差异研究

【目的】明确云烟121健康与患黑胫病烟株根系及根际土壤丛枝菌根真菌（Arbuscular mycorrhizal fungi,AMF）侵染特征的差异，为后续AMF在缓解烟株土传病害方面的应用打下理论基础。【方法】以云烟121健康和患黑胫病烟株根系及根际土壤为试验材料，采用显微形态观察法对2种烟株根系AMF侵染水平及根际土壤AMF孢子密度进行测定，应用Illumina高通量测序技术对烟株根系AMF多样性和群落结构进行分析，并应用冗余分析（RDA）和Spearman相关性系数揭示根际土壤理化性质对AMF属水平相对丰度及AMF多样性的影响。【结果】在云烟121健康和患病烟株根系及根际土壤中均检测到AMF的存在，且健康烟株根际土壤AMF孢子密度和根系AMF侵染率均明显高于患病烟株。基于高通量测序结果，在烟株根系中共检测到1410个AMF-OTUs，分属于1纲4目5科6属。在不同分类阶层上，健康与患病烟株根系AMF的优势目、科和属种类均不相同。与患病烟株相比，健康烟株根系AMF的ACE、Shannon和Chao指数更高，Simpson指数更低，差异均达显著水平（P<0.05）。PCA分析表...

Study on arbuscular mycorrhizal fungi difference in roots and rhizosphere soil in healthy and black shank infected tobacco Yunyan 121

【Objective】 To study arbuscular mycorrhizal fungi（AMF）infection symptom difference in roots and rhizosphere soil of Yunyan 121 in healthy and black shank infected tobacco plants，so as to provide theoretical reference application of AMF in soil-borne disease alleviation for tobacco plants.【Method】 Roots and rhizosphere soil of healthy and black shank infected tobacco Yunyan 121 were taken as experimental materials，microscopic morphology observation method was taken to determine AMF infection level and AMF spore density in rhizosphere soil.AMF diversity and community structure of tobacco roots were analyzed by using Illumina high-throughput sequencing technology.Redundancy analysis （RDA）and spearman correlation coefficient was conducted to reveal effects of physiochemical properties of rhizosphere soil on AMF diversity and relative abundance at genus level.【Result】AMF was detected in the roots and rhizosphere soil of healthy and black-shank-infected Yunyan 121 plants.Rhizosphere soil spore density and the AMF infection rate of healthy tobacco were significantly higher than those of infected tobacco plant.High-throughput sequencing detected 1410 AMF-OTUs in tobacco roots，belonging to 1 class，4 orders，5 families and 6 genera.Roots of healthy and infected tobacco had different dominant orders，families and genera of AMF seem from different taxonomic levels.Compared with diseased tobacco plants，healthy tobacco plant had higher ACE，Shannon and Chao indexes of AMF and lower Simpson indexes of AMF in roots，with difference reaching a significant level（P<0.05）.Principal component analysis showed that infection of black shank disease could dramatically change the AMF community structure of Yunyan 121 roots.RDA showed that soil available nutrients were negatively correlated with Chao，ACE and Shannon indexes of AMF，and positively correlated with Simpson index.Available phosphorus and available potassium were the main influencing factors for AMF diversity，and available phosphorus had the greatest influence on the relative abundance of AMF in tobacco roots at genus level.【Conclusion】Compared with healthy tobacco plants，available nutrient content in rhizosphere soil of infected tobacco plants increases and AMF spores density in soil decreases；and in tobacco roots，AMF infection rate decreases，the AMF species and diversity decreases，and AMF community structure changes significantly.