黄土高原雨养区不同种植年限紫花苜蓿土壤真菌群落的分布特征

依托布设在黄土高原雨养农业区的长期田间定位试验,以玉米田为对照、不同种植年限紫花苜蓿地(L2003,L2005,L2012)土壤为研究对象,采用真菌ITS高通量测序技术探究不同种植年限苜蓿土壤真菌群落分布与演替特征,为黄土高原苜蓿人工草地的可持续利用提供微生物参数。结果表明:黄绵土共检测到真菌6门24纲73目156科313属,主要包括子囊菌门(Ascomycota)、接合菌门(Zygomycota)、担子菌门(Basidiomycota)。苜蓿土壤和农田土壤真菌群落结构差异显著,随苜蓿种植年限延长子囊菌门相对丰度先降低后升高,接合菌门和担子菌门相对丰度先升高后降低,表现为L2003子囊菌门相对丰度显著高于L2005处理12.42%(P0.05),接合菌门相对丰度显著低于L2005处理153.54%(P0.05)。农田土壤优势属为被孢霉属(Mortierella)、绿僵菌属(Metarhizium)和腐质霉属(Humicola),苜蓿土壤共有优势真菌属为刺孢属(Phaeomycocentrospora)、白僵菌属(Beauveria)和被孢霉属。农田土壤被孢霉属相对丰度显著高于苜蓿土壤62.38%～73.48%(P0.05),随着苜蓿种植年限的延长,土壤促生菌(白僵菌属和绿僵菌属)丰度下降,部分病原菌(镰刀菌属、赤霉菌属)丰度增加。主成分分析发现,丛赤壳属(Nectria)、土赤壳属(Ilyonectria)和镰刀菌属(Fusarium)与第一主成分(PC1)具有较高的相关性,Lectera菌属、支顶孢属(Acremonium)和赤霉菌属(Gibberella)与第二主成分具有较高相关性,与第一、第二主成分相关性较高的菌属均为植物病原菌。

Distribution characteristics of soil fungal community in alfalfa field with different standing ages on the rain\|fed Loess Plateau

We selected alfalfa (Medicago sativa) artificial grasslands with three cultivated years (L2003, L2005, and L2012) on the Loess Plateau, with the corn field as control, to explore distribution and succession characteristics of alfalfa soil fungal communities in different growth years, in order to provide a scientific basis for the sustainable use of alfalfa artificial grassland on the Loess Plateau. Soil fungal community was analyzed by sequencing 18s rRNA gene amplicons. The results indicated that 6 phyla, 24 classes, 73 orders, 156 families, and 313 genera of fungi were detected in the loessial soil,including Ascomycota, Zygomycota, and Basidiomycota.The fungal community structures of alfalfa soil and farmland soil were significantly different. As the alfalfa planting period increased, the relative abundance of Ascomycota firstly decreased and then increased, and the relative abundance of Zygomycota and Basidiomycota firstly increased and then decreased. The relative abundance of Ascomycotawas L2003 that was significantly higher than that of L2005 treatment by 12.42%, and the relative abundance of Zygomycota was L2003, significantly lower than that of L2005 treatment by 153.54%. The dominant genera of farmland soil was Mortierella, Metarhizium, and Humicola, and the common dominant genera of alfalfa soil were Phaeomycocentrospora, Mortierella and Beauveria. Compared with alfalfa soil, the relative abundance of Mortierella in farmland soil increased higher significantly by 62.38%~73.48%. With increasing alfalfa growth years, the abundance of probiotic fungi decreased while some pathogenic fungi increased. Principal component analysis showed that Nectria, Ilyonectria, and Fusarium had a high correlation with the first principal component (PC1), while the genera of Lectera, Acremonium, and Gibberella had a high correlation with the second principal component (PC2), and the genera with a high correlation with the first and second principal components were all plant pathogens.