油梨根际AM真菌多样性与土壤养分相关性分析

Correlation between AM Fungal Diversity and Rhizosphere Fertility at Avocado Fields

【目的】调查广西、云南、广东等3地7个样地油梨根际AM真菌的多样性,并分析与土壤养分之间的关系,为油梨AM真菌资源收集和开发提供理论依据。【方法】采用湿筛倾析-蔗糖离心法分离土壤孢子,进行形态学鉴定,研究AM真菌的物种多样性及土壤养分的相关性。【结果】试验共分离油梨根际AM真菌3属33种,球囊霉属22种、无梗囊霉属7种、盾巨孢囊霉属4种,其中:木薯球囊霉、瑞氏无梗囊霉、深红盾巨孢囊霉、黑色盾巨孢囊霉为共有优势种,近明球囊霉、纯黄球囊霉、网状球囊霉、副冠球囊霉、疣突球囊霉、细凹无梗囊霉、疣壁盾巨孢囊霉为常见种;不同样地油梨根际AM真菌Sorenson相似性系数(0.29~0.92),普遍极高或高;相关性分析表明,AM真菌菌种丰度、Shannon-Wiener多样性指数与速效磷含量呈显著负相关。【结论】油梨根际土壤的AM真菌多样性丰富,球囊霉属为优势种群,且AM真菌种丰度多样性与土壤速效磷呈显著负相关。

【Objective】Correlation between the diversity of AM fungal community and the fertility of rhizosphere soil of avocado orchards in Guangxi,Yunnan,and Guangdong provinces was studied.【Method】Spores of AM fungi collected from the field samples were isolated by wet screening and identified morphologically.The fungal diversity and nutrient contents in the soil specimens were determined.【Result】Thirty-three species from 3 genera of AM fungi were isolated and identified.They included 22 species of Glomus,7 of Acaulospora,and 4 of Scutellospora.Among them,G.manihotis,A.rehmii,S.rubra,and S.reticulate were dominate species,and G.claroideum,G.luteum,G.reticulatum,G.coronatum,G.verruculosum,A.scrobiculata,and S.verrucose were commonly found in all samples.The Sorenson similarity coefficients on the AM fungi in the rhizosphere soils varied between 0.29 and 0.92 and were generally extremely high or high.The species richness and Shannon-Wiener index of the fungal community significantly inversely correlated with the available phosphorus in soil.【Conclusion】The AM fungi in avocado rhizosphere soil were highly diverse with Glomus being the predominant species,and the population inversely correlated to the phosphorus content in soil.