不同油葵品种对盐碱地根际土壤酶活性及微生物群落功能多样性的影响

摘要

通过盆栽试验,研究了新葵4号、新葵6号、新葵10号和美国矮大头4个油葵品种对盐碱地土壤理化、酶活性和微生物群落功能多样性的影响,以期筛选出更适宜改善盐碱地土壤质量的油葵品种.结果表明,种植新葵6号对降低盐碱地根际土壤pH值、提高土壤全氮含量和蔗糖酶活性的效果最为显著,新葵4号对提高根际土壤碱解氮、速效磷、速效钾含量以及脲酶和磷酸酶活性的效果最为显著;种植这4个品种的油葵均能显著(72 h,P＜0.05)提高盐碱地根际土壤微生物对31种碳源的平均利用率(Average well color development,AWCD),并呈现如下规律:新葵4号＞新葵6号＞美国矮大头＞新葵10号＞CK.种植这4个油葵品种均不同程度地提高了盐碱地根际土壤微生物群落的Shannon多样性指数(H)、Shannon优势度指数(D)和碳源利用丰富度指数(S),并呈现出相似的规律:新葵4号根际土的微生物多样性指数最大,而CK的最小,且显著高于CK.主成分分析表明,种植油葵改善了盐碱地根际土壤微生物的群落组成;碳水化合物、氨基酸、羧酸类化合物和聚合物是盐碱地土壤微生物利用的主要碳源.因此,在盐碱地中种植油葵可提高相关土壤理化性质和酶的活性,改善微生物功能多样性,优化盐碱地微生物的群落结构,尤其是种植新葵4号对盐碱地的改良效果最为显著.%To select the most suitable Helianthus annuus variety for improving the soil quality of saline-alkali in Xinjiang,a pot experiment was carried out to study the effects of four H.annuus varieties (Xinkui 4,Xinkui 6,Xinkui 10,and Aidatou) on the physical and chemical property,enzyme activity,and functional diversity of microbial community in rhizosphere saline-alkali soil.The research draws the following conclutions:Xinkui 6 can significantly (P＜0.05) reduce the pH of rhizosphere soil and increase its total nitrogen content as well as the activity of invertase.Xinkui 4 can significantly increase the available nitrogen content of rhizosphere soil,the content of rapid available phosphorus and potassium and the activity of urease and phosphatase.The four varieties of H.annuus can significantly increase the average well color development (AWCD) (72 h,P ＜ 0.05) of 31carbon sources for rhizosphere soil microbes in saline-alkali land,and presenting the following order:Xinkui 4 ＞ Xinkui 6 ＞ Xinkui 10 ＞ Aidatou ＞ control (CK).The four varieties of H.annuus planted in saline-alkali soil improve the Shannon diversity index (H),simpson's dominance (D) and substrate richness (S) of soil microbial community,respectively,and presenting the similar rule:the diversity indices of rhizosphere soil microbial for Xinkui 4 are the highest,which are significantly higher than the lowest CK.A principal component analysis shows that the community composition of soil microbes can be improved by planting H.annuus.The major carbon sources utilized by saline-alkali soil microbes are carbohydrates,amino acids,carboxylic acids and polymers.Therefore,planting H.annuus,especially the variety of Xinkui 4,can significantly increase physical and chemical property of soil,enzyme activity and improve the functional diversity of rhizosphere soil microbes in saline-alkali land,coupled with the optimization of community structure in saline-alkali soil microbes.