| Arbuscular mycorrhizal fungi (AMF) from the soil and ericoid mycorrhizal fungi (EMF) from Rhododendron were isolated in the study. One species of easily-cultured species AMF and five species of EMF were screened by inoculating two types of berries, strawberry and blueberry, respectively. The isolated funus were identified with the morphology and molecular biology methods. Futhermore, the effect of the AMF on the nutrient uptake and photosynthesis of strawberry was tested.One easily cultured new strain of AMF was isolated from the soil, which was identified as Penicillium pinophilum with the morphology and molecular biology methods, and a polygenetic tree was constructed based on its ITS sequences. A synthesis experiment was conducted with the isolated fungus and the strawberry Fragaria x ananassa Duch. CV. 'Zoji'. Two types of inocula, soil-root and fresh-hyphae types, were compared to uninoculated controls. The rate of arbuscular mycorrhiza (AM) photosynthesis activities and colonization were determined 60 days post inoculation. The fresh and dry weights, and phosphorus, nitrogen and potassium contents of the roots, stems, leaves and whole plants were measured 60, 80, 100 days post inoculation, respectively. The results showed that AM colonization improved the growth and photosynthesis characters of strawberry, and enhanced uptake of phosphorus and nitrogen, with little effect on the potassium. As fresh-hyphae inoculum resulted in higher inoculation rates than the root-soil inoculum, better results were received when the previous one was used as the inoculum. This was the first time to use P. pinophilum strain to synthesize mycorrhiza within the strawberry in China, and the physiology of the host plant was improved by the AM formation.On the other hand, twenty-five strains of root endophytic fungus were isolated from the Rhododendron simsii and R. dauricum L., which were used to inoculate two blueberry cultivars , 'Bluecrop' and 'Northblue'. One month post inoculatin, five strains were obseved to form the ericoid mycorrhize within the root epidermal cells of host plants. The EMF were identified by morphological characterizations and the ITS sequence analysis, and a polygenetic tree was constructed based on their ITS sequences. The infection frequencies of the host epidermal cells were calculated to range from 3.8% to 51.3% by the grid-line intersect method. |
