Gene Mapping And Transformation Applied Research Of Low Phytic Acid Maize Inbred

In our previous study, Qi319 was identified as a low phytic acid inbred line. In this study, we investigated that the content of phytic acid phosphorus in Qi319 kernels and Main Agronomic Characters in Qi319. The F2 population of Lpa241 × Qi319 was developed for molecular mapping of the lpa mutation,and Qi319 was harvested for lpa improvement lines by backcross. The main results were as follows:1. Maize bred lines Seeds from different years and harvest locations were indirectly screened by using the colorinmetric assay for high inorganic phosphorus(HIP). The result of screening was eight seeds tested from same material were consistent, it appeared that phytic acid content in Qi319 kernel is above 0.46μg. By the further research, the results of testing phytic acid P content of 6 inbred lines seeds by GB/T17406-1998 showed that, the content of phytic acid phosphorus in Qi319 kernels is 1.59 mg g-1and about one fourth of normal maize inbred lines. The results prove that Qi319 is a stable low-phytate inbred.2. In this experiment,the characterization of agronomic traits revealed that plant height,ear height, whole plant leaf number, male inflorescence branch number and ear length,kernels per row, single grain weight and kernel weight appeared normal, but the germination rate of Qi319 was 76%. Overall, the main agronomic traits of Qi319 is excellent for further applications.3. According to sequence of low acid-related genes MIPS(inositol 3-phosphate synthase), sequencing and linkage analysis results showed there was no substantive difference between Qi319 and B73.4. F2 population was generated by crossing between Qi319 and Lpa241, segregationwas found for the content of phytic acid among F2 populations. The segregation ratio of 3:1confirmed that the lpa trait was determined by a single recessive gene. On this basis,,those potentially linked markers were analyzed in recessive individuals. Finally,two In Del markers, IDP7818 and IDP7635, were found to be linked to the lpa mutation, at a distance of about 0.6 c M and 1.9 c M, respectively.5. Harvesting the low phytic acid improvement lines by cross, which as the parents of Qi319 and the parents lines of the key hybrid, such as Chang7-2 and Zheng58. PCR analysis results show that we have gained their hybrid material. This study result accumulated resources for new low-phytate maize.