青枯病不同发病率土壤对番茄植株氮素吸收效率的影响

Effects of Soils with Different Bacterial Wilt Disease Incidences on Nitrogen Absorption Efficiency of Tomato Plants

为研究青枯病不同发病率土壤对番茄植株氮素吸收效率的影响,以番茄为供试植物,采集连作多年后6种青枯病不同发病率(12.5%、21.9%、40.0%、59.4%、83.3%和91.6%)的土壤,进行盆栽试验。结果表明,随着初始土壤青枯病发病率逐渐升高,番茄植株生物量和氮素吸收效率呈下降趋势,且存在显著相关性;初始土壤中全氮、铵态氮和硝态氮含量与植株的氮素吸收效率无显著相关;初始土壤的细菌多样性和群落组成与植株的氮素吸收效率无显著相关,但基于OTU的细菌群落变化与植物氮素吸收效率呈显著相关性,溶杆菌属(Lysobacter)和藤黄单胞菌属(Luteimonas)细菌与植株氮素吸收效率呈显著正相关,其中溶杆菌属(Lysobacter)细菌同时与发病率呈显著负相关。综上,本研究发现,受不同程度的连作障碍影响,土壤的氮素含量与植物氮素吸收效率无显著相关性,而初始土壤的细菌群落与植物氮素吸收效率存在显著相关性。

In order to evaluate the effects of soils with different bacterial wilt disease incidences on nitrogen uptake efficiency of tomato plants,tomato was used as the test plant and soils with different disease incidences(12.5%,21.9%,40.0%,59.4%,83.3%and 91.6%)were collected to conduct a greenhouse pot experiment.The results showed that with the increase of initial soil bacterial wilt disease incidence,tomato plant biomass and nitrogen uptake efficiency showed a significant decreasing trend.There was no significant correlation between the contents of soil total N,ammonium N and nitrate N with plant N uptake efficiency at the beginning.No significant correlation between initial soil bacterial diversity and community composition with plant nitrogen absorption efficiency;however,significant correlation was observed between bacterial community change based on OTU analysis and plant N uptake efficiency.The relative abundances of Lysobacter and Luteimonas showed a significant and positive correlation with plant N uptake efficiency,and among which Lysobacter also showed a significant and negative correlation with tomato bacterial wilt disease incidence.In conclusion,this study observed that the initial bacterial community in soil with continuous cropping obstacle,but not nitrogen nutritional status,was correlated with the plant nitrogen uptake.