菌根真菌对白三叶根际团聚体稳定性、球囊霉素相关土壤蛋白和糖类物质的影响

Effects of arbuscular mycorrhizal fungi on aggregate stability,GRSP,and carbohydrates of white clover

盆栽条件下研究丛枝菌根真菌（地表球囊霉和隐类球囊霉）对白三叶生长、叶绿素含量、根际土壤水稳性团聚体粒级分布和稳定性,以及球囊霉素相关土壤蛋白（GRSP）和糖类物质含量的影响。结果表明,接种85d后根系菌根侵染率为35%-75%。接种处理显著提高了地上部、地下部和植株总干物质量以及叶绿素含量,其中白三叶对隐类球囊霉的依赖性高于地表球囊霉。接种菌根真菌处理也增加了根际0.25-0.5mm和0.5-1mm粒径水稳性团聚体含量,降低了1-2mm粒径水稳性团聚体含量,但没有影响2-4mm粒径水稳性团聚体含量以及平均质量直径。菌根接种增加了白三叶根际土壤易提取GRSP、总GRSP、热水提取碳水化合物和水解碳水化合物的含量。相关性分析显示,根系菌根侵染率显著地促进GRSP的含量,GRSP主要对〈1mm粒级水稳性团聚体产生正效应,团聚体稳定性主要依赖总GRSP,不同组分的GRSP对土壤糖类物质的贡献不同。

The effects of two arbuscular mycorrhizal fungi（Glomus versiforme and Paraglomus occultum）on size distribution of soil water-stable aggregate and aggregate stability,glomalin-related soil protein（GRSP）,and carbohydrates of white clover（Trifolium repens）were analyzed.Root mycorrhizal infection ranged from35%to 75%after 85 days of mycorrhizal inoculation.The inoculated treatments significantly increased shoot,root,and total dry biomass and chlorophyll content.White clover was more dependent on P.occultumthan on G.mosseae.The treatments inoculated with arbuscular mycorrhizal fungi also notably increased the content of water-stable aggregate in the size ranges 0.25-0.5mm and 0.5-1mm but significantly reduced them in the1-2mm size range.There was no effect on water-stable aggregate content in the 2-4mm size and mean weight diameter（an indicator of soil aggregate stability）.Inoculated treatments markedly increased rhizospheric soil easily-extractable GRSP,total GRSP,hot-water extractable and hydrolyzed carbohydrate contents.Correlation analysis showed that root mycorrhizal colonization was highly positively correlated with GRSP production,and GRSP had a positive effect on〈1mm size water-stable aggregates.In addition,the contribution of GRSPs to aggregate stability mainly depends on total GRSP but not on easily-extractable GRSP.GRSP fractions had different contributions to soil carbohydrates.