| The research and applied technology of rhizosphere beneficial microbial inoculums is a repeatedly interested international research subject, which is very important to the field planting, new dosage forms can help to solve this problem. With study in a deep going way, the essentiality of rhizosphere microorganism to forest survival and growth was well-known by more and more people, applied research is generally well-focused by all countries in the world. In this paper, we considered rhizosphere growth-promoting bacteria of local mangrove in the coastal areas of Guangdong as object of study, focused on separating and selecting growth-promoting bacteria from local mangrove and developed a new bacterial agent of high survival rate and convenient in industrial production and transportation.Isolation of growth-promoting bacteria from local mangrove. Used wild mangrove Avicennia marina seedlings that picked in Guangdong Nansha Wetland Park as experimental materials, we separated and selected bacterias which have the capacity of phosphate-solubilizing and nitrogen fixation, these seven kinds of growth-promoting bacteria,there are three phosphate-solubilizing bacterias selected by GuangDong Academy of Forestry, we number them P7#,07PCK,07pqwp1-5#; and also four kinds of Nitrogen-fixing bacteria, number them NGQQ②D,NGWB③+④B,MLN2#,07Nhs-7#. In pot experiments, we studied inoculation effect of seven kinds of strains on mangrove seedlings (offered by Guangdong NanSha wetland park) and the results showed comparing with contrast seedlings, the height of inoculated seedlings increased 20.4%～31.8% and the biomass increased 19.4%-21.6%, carried out significance analysis of the mass growth and biomass of mangrove seedlings, the results showed both of them reached extreme marked value; the height of phosphate-solubilizing bacteria inoculated seedlings increased 22.8%-28.5% and the biomass increased 19.4%-22.6%, carried out significance analysis of the mass growth and biomass of mangrove seedlings, the results showed both of them reached extreme marked value. In pot experiments, we tested the situation of field planting of rhizosphere growth-promoting bacteria, phosphate-Solubilizing Bacteria and Azotobacteria colonizing the Department of magnitude the number of each colony for more than 109, experimental results showed the situation of it was well. Optimization of culture medium of rhizosphere growth-promoting bacteria. Because wetland forest ecosystem is more complex than the dry land, and the growth conditions of growth-promoting were also relative complex, so optimize the standard medium of Phosphate-Solubilizing Bacteria. Via a series of single factor experiment, the best culture condition of Phosphate-Solubilizing Bacteria was:salinity 15%o, pH 8.0, carbon source dextrose, nitrogen source peptone.Develop the capsule formulation of rhizosphere growth-promoting bacteria of local mangrove. In this paper, we optimized the recipes of microcapsule, compared the configuration and rigidity of microcapsule in different recipes and selected the best recipe:2.5% sodium alginate mixed with the bacteria liquid as 3:1. Compared the capacity of bacteria with conventional liquid dosage forms in different conditions, the preserving ability of liquid form in normal temperature was the worst, the survival rate was less than 10 million after two months, the viable counts of test Phosphate-Solubilizing Bacteria and Azotobacteria were only 5.59×104 and 7.37×105, but the survival rate of dry capsule can reach 10 million in normal temperature after preserving two months later; the viable counts of test Phosphate-Solubilizing Bacteria and Azotobacteria were 11.37×106 and 10.13×107 respectively. In pot experiments, we studied inoculation effect of large capsules, micro-capsules and liquid formulations of conventional (mixed bacteria, single bacteria) that are made by selected growth-promoting bacteria on mangrove kandelia candel seedlings (offered by Guangdong NanSha wetland park) and the results showed comparing with contrast seedlings, the height of inoculated seedlings increased 12.6%～23.0% and the biomass increased 16.2%～17.5%, carried out significance analysis of the mass growth and biomass of mangrove kandelia candel seedlings, the results showed the height of seedlings reached extreme marked value; the biomass of seedlings reached extreme marked value, excluded the seedlings that inoculated by single bacteria. We tested the situation of field planting of all kinds of dosages of rhizosphere growth-promoting bacteria, experimental results showed the situation of all dosages were well, especially the microcapsule. Also the dry capsules were convenient goods than conventional liquid formulations in carrying and storage, so the advantages of capsules are obvious. |
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