不同林龄下刺梨根内生微生物群落结构特征

Characteristics of the Endophytic Microbial Community Structure in Rosa roxburghii under Different Forest Age

摘要: 内生菌是植物微生态系统的重要组成部分，不同植物器官内生细菌分布数量存在差异，为了解刺梨根内生微生物群落结构特征，以贵州省龙里县人工种植不同林龄5年、10年、15年、20年的刺梨根系为研究对象，采用高通量测序法分析了刺梨根内生细菌、真菌的群落结构特征。结果表明：刺梨随着种植年限的增加，根际土壤理化性质不断改善，20年林龄速效磷、速效钾含量达最高，分别高达187.32 mg∙kg⁻¹、578.02 mg∙kg⁻¹，10年林龄刺梨的Vc含量最高，高达13.99 mg∙g⁻¹。根内生细菌和真菌群落多样性丰富度随着种植年限增加呈上升趋势，20年树龄根内微生物群落结构多样性最丰富，OTUs值均最大。刺梨根内生微生物群落结构与土壤因子有显著相关性，与果实Vc含量无显著相关性。

Abstract: Endophytes are an important component of the plant microecosystem, and the distribution and abundance of endophytic bacteria vary among different plant organs. To understand the structural characteristics of the endophytic microbial community in the roots of Rosa roxburghii, we studied the root systems of R. roxburghii planted in Longli County, Guizhou Province, with different stand ages of 5, 10, 15, and 20 years. High-throughput sequencing was used to analyze the community structure characteristics of endophytic bacteria and fungi in the roots. The results showed that as the planting years increased, the physicochemical properties of the rhizosphere soil of R. roxburghii continuously improved. The contents of available phosphorus and available potassium reached their highest levels in the 20-year-old stand, at 187.32 mg∙kg⁻¹ and 578.02 mg∙kg⁻¹, respectively. The Vitamin C (Vc) content was highest in the 10-year-old stand, reaching 13.99 mg∙g⁻¹. The diversity of endophytic bacterial and fungal communities in the roots continuously increased with the planting years, with the 20-year-old stand exhibiting the richest diversity in the root microbial community structure and the highest OTU (Operational Taxonomic Unit) values. The structure of the endophytic microbial community in the roots of R. roxburghii was significantly correlated with soil factors but not significantly correlated with the Vc content of the fruit.