Department of Agriculture, Food and Environment, University of Catania, 95123 Catania, Italy.
Agrobiotech Soc. Coop., 95121 Catania, Italy.
Genes (Basel). 2024 Jun 21;15(7):824. doi: 10.3390/genes15070824.
Mal secco is a vascular disease of citrus caused by the mitosporic fungus . Soil containing infected plant material constitutes an inoculum source for root infections. In this study, the soil bacterial and fungal communities of five lemon orchards located in Syracuse Province (Sicily, Italy) affected by mal secco were analyzed. Soil samples were collected under lemon tree canopies and subjected to total genomic DNA extraction. The fungal DNA was detected through qPCR in all orchards, with variable concentrations. Bacterial and fungal communities were profiled using 16S and ITS amplicon-based high-throughput sequencing, respectively. According to our results, the relative abundances of the most represented bacterial phyla (e.g., Proteobacteria, Actinobacteriota, Acidobacteriota) changed across the orchards, while in the fungal community, the phylum Ascomycota was dominant, with Basidiomycota and Mortierellomycota abundances fluctuating. On the whole, β diversity analysis showed significant variation in the composition of the soil microbial communities across the orchards. This result was confirmed by the analysis of the core community (taxa present at ≥ 75% of total samples), where putative beneficial bacteria resulted in significantly enriched fungus-infected soil samples, suggesting complex microbial interactions. Our findings shed light on the composition and diversity of the soil microbiome in lemon orchards with the occurrence of mal secco infections.
马氏枯溃疡病是一种由半知菌引起的柑橘血管病。含有感染植物材料的土壤是根部感染的接种源。在这项研究中，分析了位于意大利西西里岛锡拉库萨省五个受马氏枯溃疡病影响的柠檬园的土壤细菌和真菌群落。在柠檬树冠下采集土壤样本，并进行总基因组 DNA 提取。在所有果园中均通过 qPCR 检测到真菌 DNA，其浓度不同。使用基于 16S 和 ITS 扩增子的高通量测序分别对细菌和真菌群落进行了分析。根据我们的结果，最具代表性的细菌门（例如变形菌门、放线菌门、酸杆菌门）的相对丰度在果园之间发生了变化，而在真菌群落中，子囊菌门占优势，担子菌门和无梗囊霉门的丰度波动。总体而言，β多样性分析表明，果园之间的土壤微生物群落组成存在显著差异。核心群落（存在于总样本的≥75%的分类群）的分析证实了这一结果，其中假定有益细菌在真菌感染土壤样本中显著富集，表明存在复杂的微生物相互作用。我们的研究结果揭示了发生马氏枯溃疡病感染的柠檬园中土壤微生物组的组成和多样性。
