Diversity And Distribution Of Ectomycorrhizal Fungi Of Pinus Massoniana In Guizhou

Ectomycorrhizal fungi(EMF)is a reciprocal symbiosis formed by specific fungi in soil and higher plant nutrient roots.It can effectively promote the absorption of required nutrients,water and mineral elements by symbiotic plants and promote host plants.Adversity conditions such as disease resistance,drought resistance and heavy metal resistance.Masson pine is an important native pioneer tree species for vegetation restoration in southern China.It is also an important industrial timber and oil economic tree species,and has important ecological economic value and scientific research value.This study carried out a preliminary study by exploring the distribution pattern of ectomycorrhizal fungi diversity in Masson pine in Guizhou,revealing the diversity and distribution characteristics of ectomycorrhizal fungi of P.massoniana from two habitat gradients of vertical altitude gradient and different forest age gradients.The main findings are as follows:(1)The infection rate of ectomycorrhizal fungi in Masson pine in Guizhou is about 95%.A total of 8952 ectomycorrhizal root tips from 8 study plots of Masson pine forest were combined through morphological classification and molecular biology techniques.305 effective mycorrhizal fungi sequences were obtained,and 90 ectomycorrhizal fungi OTUs were divided based on 97% similarity,all belonging to the Ascomycota and Basidiomycota.The common species(genus)and endemic species(genus)of pine mycorrhizal fungi in Guizhou have been analyzed.About 70% of rare species(genus),Russula and cotton Tomentella is an important common genus.The ectomycorrhizal fungi of P.massoniana in different forest ages belong to 48 genera and 21 species in 15 families.The dominant genera and species of ectomycorrhizal fungi of P.massoniana in different forest ages are different.In the low forest age stage,Russula and Tomentella is the main species;by the end of the forest age,the main species are Amphinema,Piloderma and Tomentella.The ectomycorrhizal fungi of P.massoniana at different altitudes belong to 42 species in 19 families and 19 genera.Among them,Russula and Hyaloscypha are common genera of ectomycorrhizal fungi at different altitudes.With the increase of altitude,the composition of ectomycorrhizal fungi of P.massoniana in different altitude gradients is different,but Russula is a common genus at all altitudes.(2)In different ages of P.massoniana forests,with the increase of forest age,the estimated richness of ectomycorrhizal fungi Chao2 index shows that it increases with the increase of forest age,that is,the pine pine fungus The abundance of root fungi is greater than that of the middle forest age stage and greater than that of the low forest age stage.However,the predicted abundance of ectomycorrhizal fungi of P.massoniana forests is less than that of P.massoniana mixed forest.In addition,in terms of species diversity,the Shannon-Wiener index of ectomycorrhizal fungi of P.massoniana in different forest ages showed that the middle forest age stage was greater than the low forest age stage and the high forest age stage,but both were lower than the masson pine needlebroadleaved mixed forest.With the increase of the age gradient of Masson pine forest,the substitution rate of ectomycorrhizal fungi gradually increased,and the species substitution rate in the later stage of the forest age was greater than that in the early stage.In the masson pine forests at different altitudes,the estimated richness of ectomycorrhizal fungi increases with altitude as the altitude increases;the predicted richness reaches about 1000 m and 1600 m above sea level The largest,but less abundant at 1200 m and 1400 m.The Ec M fungal diversity of P.massoniana increased along the altitude gradient,the species substitution rate increased,and the ShannonWiener diversity index gradually increased along the elevation gradient.In addition,the diversity of ectomycorrhizal fungi of P.massoniana increased along the altitude gradient,the species substitution rate increased,and the Shannon-Wiener diversity index gradually increased along the elevation gradient.(4)Through statistics,the average number of ectomycorrhizal fungi symbiotic with a single plant of P.massoniana is about 3.49,and the number of symbiotic ectomycorrhizal symbiosis(N)and the mass diameter of DBH(DBH)of P.massoniana are used for regression.Combined,the number of ectomycorrhizal fungi of P.massoniana fits the DBH quadratic fit,namely N = 0.53DBH-0.007DBH2-1.48,the fitting degree R2 = 0.198,the model fit is significant(P = 0.0008 <0.01).(5)The Pearson correlation analysis of Alpha mycorrhizal fungi,Chao2 index,soil factors and topographic factors of P.massoniana in Guizhou showed that: Shannon-Wiener index(H index)has a very significant positive correlation with altitude,Simpson The dominance index(P index)has a significant positive correlation with altitude,and the Pielou uniformity index(E index)has a significantly negative correlation with soil temperature.Pearson correlation analysis of ectomycorrhizal fungi diversity and longitude and latitude,elevation,slope,soil environmental factors,aboveground vegetation leaf area index and symbiotic plant DBH at different altitudes showed: H index and E index and altitude,OTUs,Significantly positive correlation,significantly negative correlation with leaf area index;P index is significantly positively correlated with altitude and OTUs.In addition,the diversity of ectomycorrhizal fungi of P.massoniana in different forest ages in Guizhou was significantly positively correlated with H index and total phosphorus,P index was significantly positively correlated with total phosphorus and negatively correlated with OTUs;Chao2 index was significantly positively correlated with total phosphorus,with Available phosphorus is significantly negatively correlated.(6)Canonical Correspondence Analysis(CCA)obtained 7 significant environmental variables that could explain a total of 45.38% of the total variability of the Ec M fungal comprehensive measure.Different genera have different preferences for environmental variables,such as the genus Ceratocystis Tylospora)and Russula have a wide range of adaptation to the environment,and the dependence on the environment is not obvious,while Amphinema and the like are more suitable for living in environments with high p H and high canopy density;Tomentella is suitable for habitats with high humidity and high p H.Clavulina is more suitable for soils with higher phosphorus and symbiotic plant forests.Phialocephala prefers environments with high available phosphorus..