Study of soil- and plant-associated bacterial diversity during early phases of maize leaf litter decomposition

We investigated the different levels of soil- and plant-associated bacterial diversity on the rates of maize leaf litter decomposition, and bacterial community dynamics during its early phases. In this study, we manipulated soil bacterial diversity by autoclaving soils and inoculating the autoclaved soil with an extract of microbes. Our approach substantially reduced bacterial diversity in autoclaved soil (Sterile soil), soil inoculated with diluted inoculum (Soil DI), soil inoculated with undiluted inoculum (Soil UI) compared to the original soil, while no significant differences in bacterial abundance were determined among the different soil treatments after 2 weeks of preincubation (between week -2 and 0). To understand the role of bacterial diversity, mainly during early phases of litter decomposition, maize leaf litter was applied to the different soil treatments and incubated for 6 weeks under a laboratory condition. Soil bacterial diversity and community composition were assessed before and during litter decomposition using 16S rRNA gene metabarcoding. Maize leaf bacterial community composition was assessed in prior to being applied to the soils.

本研究探究了土壤及植物相关细菌多样性水平对玉米叶枯落物分解速率的影响，以及叶枯落物分解早期阶段的细菌群落动态变化。本研究通过对土壤进行高压蒸汽灭菌处理，并向灭菌土壤接种微生物提取液，以此调控土壤细菌多样性。相较于原始土壤，该处理策略显著降低了高压灭菌土壤（无菌土壤，Sterile soil）、接种稀释接种液的土壤（土壤DI，Soil DI）以及接种未稀释接种液的土壤（土壤UI，Soil UI）中的细菌多样性；而在预培养2周后（即第-2周至0周期间），各土壤处理组的细菌丰度未检测到显著差异。为明确细菌多样性在叶枯落物分解早期阶段的作用，我们将玉米叶枯落物施加至各土壤处理组中，并在实验室条件下培养6周。本研究采用16S rRNA基因代谢条形码（metabarcoding）技术，在叶枯落物分解前及分解过程中对土壤细菌多样性与群落组成进行分析；并在将玉米叶枯落物施加至土壤前，对其表面的细菌群落组成开展了检测。