Analysis Of The Characteristics Of Solubilizing- Phosphorus And Colonization Of Mycorrhizal Fungi In Blueberry

Blueberries belong to the genus Vaccinium Ericaceae, it is a shallow-root plant without a big taproot, and its root is slender. Most of roots of Ericaceae plant under natural conditions can form a special class of endogenous mycorrhizal, which is known as Ericoid mycorrhizas. It plays an important role in plant nutrient absorption and improvement of plant resistance. In this paper, the blueberry is used as test material, the microstructure of mycorrhiza and the characteristic of solubilizing-phosphorus of mycorrhizal fungi were analyzed, and the characteristic of colonization of mycorrhizal fungi was also studied by denaturing gradient gel electrophoresis (DGGE). This is a basis task to develop a great number of resources of mycorrhizal fungi in blueberry. The results were showed as follows.On the basis of trypan blue staining and frozen section technique, the infection rate and microstructure of mycorrhizae in blueberries were observed under natural conditions. The results showed that fungal infection sites appeared in the epidermis, cortex and column. The column was the largest region of fungal infection, but the epidermis had less infection. The infection sites of blueberry mycorrhizal in root mostly appeared in slight-yellow brown region, the infection rate of the apical part of root was low. Few infections in the tender new-developed roots could be found. The infection rate of mycorrhizal fungi in wild blueberries from Greater Khingan Mountains region is about 54.6%.Phosphorus-dissolving capacity of mycorrhizal fungi from blueberry was analyzed and the results showed that all the seven species had the phosphorus-dissolving capacity. Two kinds of fungi with higher phosphorus-dissolving capacity were chosen and the characteristic of phosphorus-dissolving was researched. The results showed that phosphate-solubilizing fungi increased the content of inorganic phosphorus in culture medium and the content of acid in fungi both reached the highest at 144h. It indicated that the fungi secreted a large number of acids to dissolve inorganic phosphorus.Sterile seedlings of blueberry were bred by tissue culture method. The mycorrhizal fungi were inoculated to sterile seedlings. After incubation, most of mycorrhizal fungi played a positive role in promoting the growth of blueberry. The results of microstructure suggested that the infection rate of mycorrhizal fungi increased with time. After three months, the infection rate reached 70%. The content of N and P, and the activity of superoxide dismutase and catalase in leaf of plants inoculated by mycorrhizal fungi were higher than those in the control.Total DNA of soil contained mycorrhizal fungi was extracted and amplified by primers containing GC clamp. DGGE analysis of PCR production showed that mycorrhizal fungi had colonized in roots of blueberry. In addition, mycorrhizal fungi maybe one of the dominant microorganisms in soil.