水旱轮作对滩涂绿花椰菜根际土壤真菌群落结构的影响

本研究比较轮作和连作下滨海滩涂地绿花椰菜根际土壤真菌群落结构和多样性的变化特征,以探索不同轮作方式减缓绿花椰菜连作田连作障碍的效果。采用Illumina Miseq高通量测序技术,分析单季稻-绿花椰菜水旱轮作、南瓜-绿花椰菜旱旱轮作和绿花椰菜连作3种耕作方式对绿花椰菜根际土壤真菌群落结构和多样性的影响。结果表明,在浙江省台州湾滨海滩涂地绿花椰菜种植区,水旱轮作、旱旱轮作和连作绿花椰菜根际土壤共获得11门、27纲、52目、94科、155属真菌。在门水平上相对丰度较高的为子囊菌门Ascomycota、油壶菌门Olpidiomycota、担子菌门Basidiomycota、接合菌门Zygomycota、壶菌门Chytridiomycota。与连作相比,轮作显著提高了绿花椰菜根际土壤中子囊菌门、壶菌门菌群的相对丰度,而以水旱轮作对其相对丰度的提高幅度更大。轮作显著降低了绿花椰菜根际土壤中油壶菌门、接合菌门菌群的相对丰度,而以水旱轮作对这2门菌群相对丰度的降低幅度更大。在属水平上轮作显著降低了绿花椰菜根际土壤中油壶菌属Olpidium、镰刀菌属Fusarium等的相对丰度,显著提高了绿花椰菜根际土壤中格孢腔菌属Pleospora的相对丰度,而水旱轮作更提高了格孢腔菌属的相对丰度,降低了油壶菌属、镰刀菌属的相对丰度。因此,轮作能改善台州湾滨海滩涂地上绿花椰菜根际土壤真菌群落结构,但水旱轮作更能增加绿花椰菜根际土壤真菌有益菌丰度,减少绿花椰菜根际土壤真菌有害菌群丰度,提高根际土壤真菌多样性指数,改良绿花椰菜根际土壤生态环境。

Effects of paddy rice-upland crop rotation on fungal community structure and diversity in the rhizosphere of Brassica oleracea var.italica

Illumina MiSeq high-throughput sequencing technology was used to examine the effects of three different cropping treatments (rotation of paddy rice and Brassica oleracea var. italica, rotation of pumpkin and B. oleracea var. italica, and continuous cropping of B. oleracea var. italica) on the fungal community structure and diversity in the rhizosphere of B. oleracea var. italica cultivated in the coastal beach area in Taizhou Bay, Zhejiang Province, China. A total of 11 phyla, 27 classes, 52 orders, 94 families, and 155 genera of soil fungi was isolated. Ascomycota, Olpidiomycota, Basidiomycota, Zygomycota, and Chytridiomycota were the dominant phyla with high relative abundance. At the phylum level, rotation cropping notably improved the relative abundance of Ascomycota and Chytridiomycota but decreased that of Olpidiomycota and Zygomycota in B. oleracea var. italica rhizosphere soil. At the genus level, rotation cropping decreased the relative abundance of Olpidium and Fusarium, whereas increased that of Pleospora in B. oleracea var. italica rhizosphere soil. Paddy rice-upland crop rotation very significantly heightened diversity and richness indices of rhizosphere fungi, while upland crop rotation and B. oleracea var. italica continuous cropping took less effect. Compared with long-term continuous cropping of B. oleracea var. italica, paddy rice-upland crop rotation and upland crop rotation could improve the fungal community structure in B. oleracea var. italica rhizosphere. In particular, paddy rice-upland crop rotation had better effects on improving the abundance and diversity of beneficial fungi and decreasing those of harmful fungi in B. oleracea var. italica rhizosphere, enhancing the ecological environment of the rhizosphere. These findings provide practical evidence of achieving high yield and excellent quality of B. oleracea var. italica through rotation cropping.