College of Life Sciences, Fujian Agriculture and Forestry University, Fuzhou 350002, Fujian, China.
Key Laboratory of Crop Ecology and Molecular Physiology, Fujian Agriculture and Forestry University.
Plant Dis. 2020 Jan;104(1):25-34. doi: 10.1094/PDIS-04-19-0833-RE. Epub 2019 Nov 13.
Replant disease caused by negative plant-soil feedback commonly occurs in a monoculture regime. Here, barcoded pyrosequencing of 16S ribosomal DNA amplicons combined with phylogenetic investigation of communities by reconstruction of unobserved states (PICRUSt) analysis was applied to study the shifts in soil bacterial community structure and functional potentials in the rhizosphere of under consecutive monoculture and different soil amendments (i.e., bio-organic fertilizer application [MF] and paddy-upland rotation [PR]). The results showed that the yield of tuberous roots decreased under consecutive monoculture and then increased after MF and PR treatments, which was consistent with the changes in soil bacterial diversity. Both principal coordinate analysis and the unweighted pair-group method with arithmetic means cluster analysis showed the distinct difference in bacterial community structure between the consecutively monocultured soil (relatively unhealthy soil) and other relatively healthy soils (i.e., newly planted soil, MF, and PR). Furthermore, taxonomic analysis showed that consecutive monoculture of significantly decreased the relative abundances of the families Burkholderiaceae and Acidobacteriaceae (subgroup 1), whereas it increased the population density of families Xanthomonadaceae, Phyllobacteriaceae, Sphingobacteriaceae, and Alcaligenaceae, and . In contrast, the MF and PR treatments recovered the soil microbiome and decreased abundance through the different ways; for example, the introduction of beneficial microorganisms (in MF) or the switching between anaerobic and aerobic conditions (in PR). In addition, PICRUSt analysis revealed the higher abundances of membrane transport, cell motility, and DNA repair in the consecutively monocultured soil, which might contribute to the root colonization and survival for certain bacterial pathogens under monoculture. These findings highlight the close association between replant disease of and the variations in structure and potential functions of rhizosphere bacterial community.
连作障碍通常发生在单一栽培制度下。在这里，我们应用了 16S 核糖体 DNA 扩增子的条形码焦磷酸测序和未观察到状态的群落重建的系统发育分析（PICRUSt）分析，来研究连续单一栽培和不同土壤改良措施（即生物有机肥应用[MF]和稻旱轮作[PR]）下 根际土壤细菌群落结构和功能潜力的变化。结果表明，在连续单一栽培下，块根产量下降，然后在 MF 和 PR 处理后增加，这与土壤细菌多样性的变化一致。主坐标分析和非加权对组平均聚类分析都表明，连续单一栽培土壤（相对不健康的土壤）和其他相对健康的土壤（即新种植土壤、MF 和 PR）之间细菌群落结构存在明显差异。此外，分类分析表明，连续单一栽培显著降低了伯克霍尔德氏菌科和酸杆菌科（亚群 1）的相对丰度，而增加了黄单胞菌科、叶杆菌科、鞘脂杆菌科和产碱杆菌科的种群密度，和. 相比之下，MF 和 PR 处理通过不同的方式恢复了土壤微生物组，并通过降低 的丰度来减轻连作障碍；例如，引入有益微生物（在 MF 中）或在厌氧和需氧条件之间切换（在 PR 中）。此外，PICRUSt 分析显示，连续单一栽培土壤中膜转运、细胞运动和 DNA 修复的丰度较高，这可能有助于某些细菌病原体在单一栽培下的根定植和存活。这些发现强调了 连作障碍与根际细菌群落结构和潜在功能变化之间的密切联系。
