娃娃菜不同轮作模式下根际土壤微生物群落多样性特征

Diversity characteristics of rhizosphere soil and microbial community under different rotation patterns of baby cabbage

为探明不同作物与娃娃菜轮作后的效果,在宁夏南部山区进行定位试验,采用高通量测序技术,结合土壤理化性质及酶活性,比较分析了娃娃菜-西兰花(CMB)、娃娃菜-大葱(CMG)、娃娃菜-洋葱(CMO)、娃娃菜-土豆(CMP)和以娃娃菜连作(CCC)为对照的5个处理的微生物多样性,旨在筛选出适宜与娃娃菜轮作的作物,为从栽培模式选择角度缓解或避免娃娃菜连作障碍提供理论依据。试验结果表明:与连作相比,轮作马铃薯土壤硝态氮含量最高为12.8 mg·kg^(-1),轮作大葱土壤速效磷含量最高为75.74 mg·kg^(-1),但不同轮作模式下速效钾和有机质含量有所下降。轮作马铃薯土壤的碱性磷酸酶、蔗糖酶与轮作洋葱土壤的过氧化氢酶、脲酶显著低于娃娃菜连作和轮作其他作物。细菌丰度在属水平上的结果表明轮作导致大部分有益细菌属丰度升高,如贪铜菌属(Cupriavidus)、鞘脂单胞菌属(Sphingomonas)、柄杆菌属(Caulobacter)等,有害菌及其他部分未分类功能作用菌属丰度降低,如伯克氏菌(Burkholderiaceae)、黄杆菌属(Flavobacterium)等。真菌群落组成研究结果显示,子囊菌门(Ascomycota)是连作与轮作模式下共有的优势菌群,同时轮作洋葱CMO和轮作马铃薯CMP中多真菌属丰度最低且与连作CCC之间存在显著差异。冗余分析表明,土壤硝态氮是改变娃娃菜连作与不同轮作模式下细菌和真菌群落结构的最重要因素。综上所述,不同作物与娃娃菜轮作会造成土壤化学性质、酶学性质及微生物多样性的改变,其中以洋葱与马铃薯在各方面指标中表现效果最佳,建议宁夏南部山区冷凉蔬菜产业中将娃娃菜-洋葱和娃娃菜-马铃薯作为主要的轮作模式进行推广。

A localization experiment was carried out in the southern mountainous area of Ningxia to explore the effects of different crops and baby cabbage rotation on soil environment.The microbial diversity of five treatments of baby cabbage-broccoli(CMB),baby cabbage-green onion(CMG),baby cabbage-onion(CMO),baby cabbage-potato(CMP)and baby cabbage continuous cropping(CCC)were compared and analyzed by high-throughput sequencing technology combined with soil physical and chemical properties and enzyme activity.The aim was to screen out suitable crops for baby cabbage rotation and provide theoretical basis for alleviating or avoiding continuous cropping obstacles of baby cabbage from the perspective of cultivation mode selection.The results showed that compared with continuous cropping,the highest content of nitrate nitrogen in potato soil was 12.8 mg·kg^(-1),and the highest content of available phosphorus in spring onion soil was 75.74 mg·kg^(-1).However,the content of available potassium and organic matter decreased under different rotation patterns.Alkaline phosphatase,sucrase in potato soil and catalase and urease in onion soil were significantly lower than those in baby cabbage continuous cropping and other crops.The results of bacterial abundance at the genus level showed that rotation led to the increase of the abundance of most beneficial bacteria,such as Cupriavidus,Sphingomonas,Caulobacter,etc.,while the abundance of harmful bacteria and other unclassified functional bacteria such as Burkholderiaceae and Flavobacterium decreased.The results of fungal community composition indicated that Ascomycota was the common dominant flora under continuous cropping and rotation mode.At the same time,there was no fungus genus with the highest abundance in the soil of onion and potato rotation and there was a significant difference between the soil of baby vegetable and that of continuous cropping.Redundancy analysis showed that soil nitrate nitrogen was the most important factor for changing the community structure of bacteria and fungi under continuous cropping and different rotation patterns.To sum up,different crops and baby cabbage rotation caused changes in soil chemical properties,enzymatic properties,and microbial diversity.Of which onion and potato had the best performance in all indicators.It is suggested that baby cabbage-onion and baby cabbage-potato rotation should be popularized as the main rotation mode in the cold vegetable industry in the mountainous area of Southern Ningxia.