| Phosphorus is one of important element in plants, which mainly in the form of phytate, the content of phytate in seeds is about 70% of its total phosphorus. The phytase can broken down phytic acid into inositol and free inorganic phosphate, as a source of nutrition for the growth of plant seedlings. The content of natural phytase in plants is low, and it is not enough to make plants to release sufficient quantities of inorganic phosphorus from phytic acid.China is the second largest maize producer in the world.Although maize can not provide the main phosphorus source for animal growth and development as an important food crop and feed crops, but it is the most important ingredient of animal feed. Useing of the inherent biological characteristics of crops, digging their own potential of efficient absorption and utilization for phosphorus, and the use of bio-engineering section to solve the above problem has almost become a hot area of plant biology research. Through plant genetic engineering to make phytase highly expressed in maize, both degradation of vivo phytic acid, the release of inorganic phosphorus, improving monogastric animals in the utilization of phosphorus and reduce the phytate phosphorus pollution for the environment; and reducing plant acid on divalent cations, such as protein and vitamin complex to enhance the added value of maize on the nutritional quality of development, commercial quality, high-quality processing of high quality maize is of great significance.The study explores the embryogenic callus induction of factors, results showed that the callus, the inoculation methods on callus induction no significant impact; maize callus of immature embryos of the most appropriate diameter should be ranged between 1.5～2.0mm; genotype of callus induction is an important factor, this experiment eight varieties H99 induction rate up to 46.2%, followed by Dan988 (42.2%),but A188 is only 10%; For different genotypes of maize callus induction, N6, MB, and MS medium which can be induced embryogenic callus induction effect of N6>MB>MS; sucrose as a culture the base of the main carbon source, its optimal concentration should be 30～40g/L range; 2,4-D concentration of 2mg/L in favor of maize when callus induction, subculture should be appropriate reduce 2,4-D; medium supplemented with lOmg/L of AgNO3 significantly improved when the embryogenic callus induction rate, more genetic research to establish a good foundation for transformation system.The study use agrobacterium-mediated and pollen tube channel two methods to study genetic transformation of different maize genotypes. First it studied the factors of effect transformation efficiency of agrobacterium-mediated methods, the results show that the infection effect of agrobacterium strains EHA105 is better than EHA101; when the bacterial concentration OD600 is 0.5-0.6, the time is 20 minutes is the most beneficial conditions for genetic transformation of maize callus. Meanwhile it discussed the screening range of herbicide different concentrations and the research shows that the most appropriate critical concentration of herbicide screening should be 3.0～3.5 mg/L, the result provide the reference for the application of herbicide in maize genetic transformation.Generally using the pollen tube pathway into plasmid DNA concentration of 500μg/mL, import volume of 200μL to achieve a higher conversion rate. The study use two methods to import the phytase gene into different maize inbred line and use PCR to detect the To transgenic plants,the result showed that some transgenic plants were PCR positive. On the roots of these transgenic plants for the specific activity of phytase, the results show that the specific activity of its internal phytase was significantly increased compared to control, proving phytase gene was integrated into the genome of maize chromosomes and carried out effective expression.
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