Isolation Of Endophytic Fungi Of Cunninghamia Lanceolata And The Influence On Host's Growing

Endophytic fungi can alleviate a variety stress environments of plant and promote the growth of the host has been confirmed by many studies of the predecessors.While Chinese fir as the south fast-growing economic tree,research on endophytic fungi of Chinese fir is particularly necessary to promote its growth and development particularly in Southern soil.In this study,after the separation and purification different organs of Chinese fir endophyte fungi,the dominant bacteria and phosphate solubilizing bacteria are screened out.The effects of endophyte infection on Chinese fir are determined under common conditions and low phosphorus conditions by measuring indicators to analyze whether endophyte fungi can promote the host growth and development or not.The main findings are obtained as follows:One hundred and twenty nine kinds of endophytic fungi were isolated from the healthy organs of Chinese fir,including 57 strains in stems,40 strains in roots,only 32 strains in leaves.Effects of endophytic fungi on promoting the host growth under common conditions:(1)Through the analysis of the height,ground diameter,root-shoot ratio and biomass,CG2 strain could significantly promote the growth of Chinese fir seedlings in five strains,namely aJ4,NG6,CG2,CG,and AY 13.(2)Effects of endophytic fungi on photosynthesis were analyzed by measuring chlorophyll content and chlorophyll fluorescence parameters,aJ4 had better effect on Chinese fir seedlings photosynthesis.(3)Study on the inoculation methods of endophytic fungi on growth of Chinese fir was set with crown inoculation method and root inoculation method.Research found that different strains in two methods showed different results,but the root inoculation method had more effective influence comprehensively than crown inoculation method.Effects of endophytic fungi on promoting the host growth under low phosphorus conditions:(1)Effects of endophytic fungi on seedling biomass under low phosphorus stress:strain AJ14 could promote plant growth in different low phosphorus stress gradient,strain NG1 and AJ6 only to a certain extent,could alleviate the effects of phosphorus stress on plants.The root-shoot ratio indicator showed that strain NG1 had a stronger ability to relief the stress damage.Totally,compared with the other strains,the effects of NG1 in alleviating low phosphorus stress and promote the ability of plant biomass storage was better.(2)Effects of endophytic Fungi on photosynthetic characteristics of Chinese fir low phosphorus stress was determinated by the chlorophyll content and chlorophyll fluorescence parameters,five phosphorus solubilizing fungus in promoting host photosynthetic characteristics were not significant in alleviating the harmness of phosphorus stress.(3)The analysis of the effects of endophytie fungi on plant nutrients under low phosphorus stress was by measuring the indicators of P content,K content and C,N content of the aboveground part and underground part.The results showed that AJ6 could enhance the P content significantly,especially in normal condition,middle level stress condition and low level stress conditions,and the effects was more significant on the aboveground than the underground part;NG1 can effectively improve the P content of both aboveground part and underground part under middle level condition.The K content of the control seedlings was respectively higher than the seedlings with endophytic fungi.The plant C,N content of inoculated plants were generally higher than control,and aboveground part was higher than underground part,this is mainly because the nitrogen content of the underground part was less than aboveground parts.