马铃薯长期连作对土壤真菌群落特征的影响

Effects of potato continuous cropping on soil fungal community characteristics

利用田间长期定位试验,2019年基于ITS高通量测序研究马铃薯/春小麦/碗豆轮作(R)、马铃薯连作1 a(C1)、3 a(C3)、5 a(C5)、7 a(C7)和9 a(C9)的土壤真菌群落结构的演替特征。结果表明:随着马铃薯连作年限的增加,土壤真菌菌群丰度和Chao1显著增加,C7和C9马铃薯土壤真菌菌群丰度最高,R土壤真菌菌群丰度最低,C7和C9真菌群落的相似度较高,C7、C9处理与R处理的真菌群落相似度低,C1、C3、C5的真菌群落结构介于C7、C9与R之间;土壤真菌群落的相似度在纲水平上分为两类,C7和C9为一组,R、C1、C3、C5为一组;在不同连作年限的马铃薯农田土壤中,共检测到273个真菌属,其中有13个真菌属处理间差异显著,其中,青霉菌(Penicillium)在C5、C7和C9土壤中数量显著高于R,绿僵菌属(Metarhizium)在C5、C7、C9中相对丰度显著高于R、C1、C3,镰刀菌属(Fusaruim)在C5中相对丰度达最高,显著高于R、C1、C3以及C7、C9;马铃薯连作5 a后引起农田真菌群落分布发生变化。青霉菌、绿僵菌属在长期连作农田中大量富集,镰刀菌属数量下降,连作障碍程度趋于减缓。

In this study,a long-term field positioning experiment was used to study the succession characteristics of soil fungal community structure in potato/spring wheat/soybean rotation(R),potato continuous cropping for 1 year(C1),3 years(C3),5 years(C5),7 years(C7)and 9 years(C9)based on ITS high-throughput sequencing in 2019.The results showed that with the increase of continuous cropping years,the richness and Chao1 of soil fungi increased significantly.The richness of C7 and C9 soil fungi was the highest,while the richness of R soil fungi was the lowest.The similarity of C7 and C9 fungal communities was higher,but the similarity of C7 and C9 fungal communities was lower than that of R.The fungal population structure of C1,C3 and C5 were between C7,C9 and R.At the class level,the similarity of soil fungal communities was divided into two groups:C7 and C9 in one group,and R,C1,C3 and C5 in one group.A total of 273 fungal genera were detected in potato soil of different continuous cropping years,among which 13 fungal genera were significantly different.The number of Penicillium in C5,C7 and C9 soil was significantly higher than that in R soil.The relative abundance of Metarhizium in C5,C7 and C9 was significantly higher than that of R,C1 and C3,while the relative abundance of Fusaruim in C5 was the highest,significantly higher than that of R,C1,C3,C7 and C9.The distribution of fungal community changed after 5 years of continuous potato cropping.Penicillium and Metarhizium were enriched and Fusaruim specieswere reduced in long-term continuous cropping farmland.The degree of continuous cropping obstacle tended to be reduced.