Studies On The Nutrition Characteristics And The Inoculating Effects Of Neuchi Fungi From Rhododevdron Fortunei

The fungi isolated from Rhododevdron fortunei under different natural habitats were used as materials and MMN medium was adopted to study the nutrition characteristics,and the best growth conditions were also discovered.Moreover,the selected mycorrhizal fungi were successfully inoculated back into Rhododevdron fortunei to carry out the studies on the effects of pH values and nitrogen sources on the infection rate and that of mycorrhizal fungi on the growth of Rhododevdron fortunei inoculated seedlings.The main results were described as follows:1.Screening suitable pH values for 16 strains of fungi separated from the roots of Rhododevdron fortuneiThe fungi isolated from the roots of Rhododevdron fortunei were used as materials to study their pure cultures under different pH value conditions.The results showed that 50.00%of all the mycorrhizal fungi reached their maximum diameter colony at the pH value of 6.00,while 43.75% achieved their maximum mycelium dry weight.Detailedly,a majority of the fungi could grow well on weak acidic culture media,while some of them could grow on weak alkaline media,such as the Strain Oi-2,Oi-3,Unknow-2 and Unknow-5 reach,whose diameter colony was higher at 7.00-8.00 pH value,and Phialocephala fortinii fungi achieved their maximum mycelium dry weight at at 7.00-8.00 pH value.The majorities of the fungi grew fast at high pH values.The phenomenon was also found that some enzymes were excreted around the colonies when incubated at high pH value,and the color of the mycelium was weaker than those incubated at low pH value.2.The survial rate of inoculated seedlings of Rhododevdron fortunei on the media at different pH valueThe seedlings inoculated with different mycorrhizal fungi that cultured on the media with pH value were used as materials,and the results showed:when cultured at a low pH value range,the survival rate showed no obvious differences between inoculated seedlings and uninoculated seedlings,and both reached 75.00%.The survival rate descended when pH ascended,which revealed apparent differences between inoculated seedlings and uninoculated seedlings.The survival rates of inoculated overtopped 8.33%-33.33%than those of the uninoculated on the media at 6.00 pH value.And the survival rate of inoculated went ahead 16.67%-76.67%than that of the uninoculated on the media at 7.00 pH value.When cultured on the media at 8.00 pH value, no other than the Strain Oi-7 showed influences on Rhododevdron fortunei seedlings,whose survival rate was 8.33%higher than that of the uninoculated. 3.Screening suitable nitrogen sources for 16 fungi separated from the roots of Rhododevdron fortuneiThe fungi isolated from the roots of Rhododevdron fortunei were used as materials to syudy their pure cultures under different nitrogen sources,The results showed that Rhododevdron fortunei's utilization capability of nitrogensource were different,the best was inorganic nitrogen. 37.50%of the fungi reached their maximun diameter colony when growing at inorganic nitrogen, 75.50%of them achieve their maximum mycelium dry weight,but the Strain Oi-5,Oi-7,Ph-3 and Unknow-5 reached their maximum diameter colony at organic medium,when the Strain Unknow-3,Unknow-4 and Unknow-5 achieved their maximum mycelium dry weight at organic medium.Much of the fungus grew fast at Ca(NO₃)₂ and BSA media.Phenomena were also found that when cultured at organic media,the surface of the colonies were smooth,clearing zones appeared around the colonies,and the color of the mycelium was weaker than growing at inorganic media.4.The growth of inoculated seedlings of Rhododevdron fortunei at media with different nitrogen sourceTaking the fungi isolated from the root of Rhododevdron fortunei as materials,the study put emphasize on dry weight,hight,average length of root,leaf number of inoculated seedling,the result showed that when growing at different nitrogen source media,all the fungi could infect Rhododevdron fortunei,especially cultured at organic nitrogen media,and the Strain Oi-1, Unknow-5 reach the top infection rate.All the seedlings grew well than those uninfected when growing at nitrogen source media,and they grew well at organic nitrogen medium than at inorganic nitrogen media.2 of the 5 inoculating strains of fungi,Oi-3 showed the best obvious affection and then Oi-7.Seedlings inoculated Oi-3 and Oi-7 reached obvious parameters than these uninoculaed,such as dry weight,hight,average length of root and leaf number.Seedlings inoculated with Unknow-5 and Oi-3 grew well at Ca(NO₃)₂ media than growing at(NH₄)₂HPO₄ media.This experiment screened the best pH and nitrogen source for 16 fungi that collected from Rhododevdron fortunei's root in different natural habitats;then 5 srains of mycorrhizal fungi were selected and inoculated back into Rhododevdron fortunei to analyze the effects of pH and nitrogen source on the inoculated seedlings.The reseach laid certain theoretical basis on the introduction and landscape application of Rhododevdron fortunei,and provided some clues for the research of ericoid mycorrhiza and its effects.