干旱与盐胁迫对花生根际土壤细菌群落结构和花生产量的影响

以花生品种花育25号为试验材料,采用盆栽试验研究了开花期干旱和盐分胁迫对花生生长发育和荚果产量的影响,并运用高通量测序技术分析干旱、盐胁迫及旱盐双重胁迫下,花生根际土壤细菌群落结构的变化特征。结果表明: 不同胁迫处理花生根际土壤细菌群落均以变形菌门、放线菌门、Saccharibacteria、绿弯菌门、蓝藻菌门和酸杆菌门为主。干旱、盐胁迫及旱盐双重胁迫均不同程度降低了变形菌门和放线菌门的相对丰度,但显著提高了蓝藻菌门的含量,且旱盐双重胁迫较其单一胁迫引起的根际蓝藻菌门丰度变化更显著。土壤细菌功能预测分析显示,信号转导机制、防御机制及翻译后修饰、蛋白质周转和分子伴侣等相关功能在旱盐双重胁迫的细菌中活性更强,可能对花生生长及胁迫应答具有重要影响。统计学分析显示,开花期干旱、盐胁迫和旱盐双重胁迫严重影响花生生长发育,并显著降低产量。研究结果可为通过改良土壤微生物环境来提高植物胁迫耐受性提供参考。

Effects of salt and drought stresses on rhizosphere soil bacterial community structure and peanut yield

A pot experiment with Huayu 25 as experimental material was conducted, with treatments of drought and salt stresses. The effects of drought and salt stresses at the flowering stage on the plant morphology, pod yield, and soil bacterial community structure in the rhizosphere were examined. The results showed that Proteobacteria, Actinobacteria, Saccharibacteria, Chloroflexi, Cyanobacteria, and Acidobacteria were the dominant phyla in the rhizosphere soil of peanut. Compared with that under normal conditions, the relative abundance of Proteobacteria and Actinobacteria dramatically decreased, while that of Cyanobacteria evidently increased in drought-treated and salt-treated soil. Moreover, the variation of Cyanobacteria abundance caused by combined drought and salt stresses was stronger than that caused by single drought or salt stress. Functional meta-genomic profiling indicated that a series of sequences related to signaling transduction, defense mechanism and post-translational modification, protein turnover, chaperones were enriched in rhizosphere soil under stressed conditions, which might have implications for plant survival and stress tolerance. Drought and salt stress affectedpeanut growth and reduced pod yield. Results from this study would present reference on the future improvement of stress tolerance of peanuts via modifying soil microbial community.