Dynamic Changes Of Ectomycorrhizal Fungal Community In Pinus Koraiensis With Time Scale And The Influencing Factors

Ectomycorrhizae is the symbiosis formed by the roots of woody plants and ectomycorrhizal fungi(Ec MF).It plays important role in establishing and maintaining the forest ecosystem.In this study,methods of mycorrhizal fungal ecology combined with molecular biology were used to investigate the community structure and change rules in three dimensions,including of above ground,root tips and soil bulk,at the same time.The correlation between the changes of the Ec MF community composition and other biological and abiotic factors were analyzed based on different time scales using biostatistics methods.The following showed the results.(1)In the growing season(June-October),the change rules and driving factors of mycorrhizal fungi community in the same Pinus koraiensis forest were investigated.The Ec MF fruiting bodies mainly appeared from July to September,and September got to peak,which belongs to Ramaria,Thelephora,Russula,Lactarius and Suillus.The Ec MF diversity indexes in the root and soil showed drop after increased,the diversity of Ec MF in June was significantly higher than that in other months.The dominant Ec MF genera in roots were Suillus,Sebacina,Tomentella,Russula,Amphinema,Meliniomyces,Membranomyces and Rhizopogon.The dominant Ec MF genera in soil were Suillus,Sebacina,Tomentella,Russula,Tylospora,Membranomyces,Rhizopogon,Inocybe and Entoloma.Soil fungi was the one of the main factors,which influencing the richness of some Ec MF in root tips because more than 85% of the Ec MF genera in the roots shared with the habitat soil.Some Ec MF in root tipshad linear correlation with the fungi from the habitate soil.The soil p H,effective nitrogen,effective phosphorus and available potassium of soil influenced the composition of Ec MF community of Pinus koraiensis forest,which showed positive or negative correlations with the richness of the dominant genera.(2)The method of space-for-time substitution were used as an alternative to investigate the variation in root Ec MF communities with long time scale.The Ec MF diversity in the roots and the habitat soil increased with forest ages.The diversity of Ec MF from the Pinus koraiensis virgin forest lands with >150 years old was significantly higher than that in other collection sites.The dominant Ec MF genus both in the roots and the habitat soil from five years old seedlingswas Amphinema.The dominant Ec MF genera in the roots from 60 years old forest lands were Sebacina,Tomentella,Suillus,Russula,the dominant Ec MF genera in soil from 60 years old Pinus koraiensis forest lands were Sebacina,Russula,Membranomyces,Tomentella and Inocybe.The dominant Ec MF genera in the root tips and soil from 60 years old Pinus koraiensis forest lands with thinning were Suillus and Sebacina.The dominant Ec MF genera in roots from >150years old Pinus koraiensis virgin forest lands were Russula,Meliniomyces,Membranomyces,Tylospora and Piloderma.The dominant Ec MF genera in soil from >150 years old Pinus koraiensis virgin forest lands were Russula,Clavulina,Piloderma and Tomentella.The fungi from soil was one of the factor influencing the richness of Ec MF in the roots,about more than60% of the Ec MF genera in the roots shared with the habitat soil at different collection sites.Meantime,some Ec MF in roots had linear correlation with the fungi from habitat soil.Effective nitrogen,available potassium and p H of soil influenced the composition of Ec MF community in Pinus koraiensis forest,which showed positive or negative correlations with the richness of the dominant genera.(3)In conclusion,the main ectomycorrhizal fungi of Pinus koraiensis are Amphinema,Clavulina,Entoloma,Inocybe,Lactarius,Meliniomyces,Membranomyces,Rhizopogon,Ramaria,Russula,Sebacina,Suillus,Thelephora,Tomentella,Tylospora,Piloderma.The Ec MF community formation in different time scales in the same climatic zone is mainly affected by the habitat soil,the root system of Pinus koraiensis,the soil p H,the available potassium content and the available nitrogen content,while the temperature and rainfall have little influence.