Abstract
A two-year field experiment was carried out in order to study the occurrence degree and mechanism of apple replant disease (ARD) in the apple orchards with different soil textures. So we can adopt appropriate control measures according to the severity of ARD. Healthy two-year-old seedlings with consistent growth were selected, of which the root stock was T337 and the scion was Yanfu 3. There were significant differences in biomass between methyl bromide fumigation and replanted treatments, and the difference was the largest in clay loam, followed by sandy loam, and loam, which verified ARD in clay loam was most serious, followed by sandy loam and loam. Based on high-throughput sequencing of fungi in soil samples, fungal richness and diversity were the highest in clay loam, followed by sandy loam, and loam. The relative abundance of Fusarium in SX, SL, FX, FL, WX and WL was 7.33%, 19.32%, 2.70%, 4.24%, 10.71% and 23.87%, respectively. Based on Real-time quantitative analysis, there were significant differences in the number of Fusarium oxysporum and Fusarium solani between methyl bromide fumigation and replanted treatments, i.e., clay loam > sandy loam > loam. Fusarium was the main pathogen causing ARD. This shows that ARD is the most serious under replanted clay loam condition. High-throughput sequencing technology was used to prove the difference in Fusarium was one of the important reasons for ARD under different soil textures. This technology provides a new idea for the prevention and control of ARD.
