Effect Of Endophytic Fungi Isolated From Wild Vaccinium Vitis-idaea L. On Growth Promotion Of Cultivated Blueberry

The cultivation of blueberry developed rapidiy in China recent years. How to enhance plant growth must be resolved quickly. Physiology improvement of endophytic fungi had been confirmed by many researches. It is meaningful to use endophytic fungi in cultivation of blueberry.Six endophytic fungi strains were isolated from the roots of wild Vaccinium vitis-idaea L., and three of them were selected while they had the ability to infect cultivated blueberry, which were named as F1, F2 and F3. Strains F1 and F2 were identified as Neonectria sp.1 and Neonectria sp.2 respectively by morphology observation and molecular biology defection. The strain F3 was not identified yet. A polygenetic tree was constructed based on their ITS sequences. The genetic relationship of F1 and F2 was very close, F3 clustered into seperated group.Six treatments of F1, F2, F3, F1*F2, F1*F3 and F2*F3 were assigned and inoculated with fresh mycelium. And blueberry cultivar 'Bluecrop' were used as host. The dry and fresh weights, nitrogen, phosphorus and potassium contents of the plants were measured 40,60,80 days post inoculation, respectively. We also detected plant height, leaves 'numbers and tills' numbers of test plants in corresponding days. The colonization rates were between 0 to 25.1% after 40 days inoculation. Treatment of F1*F2 could significantly improve the growth of blueberry plants. Compared with the control, treatment of F1*F2 increased 60.7% of leaves' number and 76.1% of the whole plant's dry weight 80 days post inoculation and significantly enhanced uptake of nitrogen and phosphorus, but show little affect on the potassium. Nitrogen and phosphorus contents of plants'aerial parts were increased by 69.9% and 83.0% when N and P contents of the roots were higher than control by 88.8% and 48.2%. The results showed that combined application of endophytic fungi strains may affect the ability to enhance plant growth more than single inoculation.Three fungi may accelerate plant growth through promotion of plants to uptake nutrients based on the growth-promoting experiments. F2 strain may solubilize inorganic sources of Phosphorus—Ca3(PO4)2, and its Solubilizing affect was better than F1 or F3 cultured in liqiud medium after 84 h.