| Phytic acid (myo-inositol 1,2,3,4,5,6-hexakisphosphate) is the primary storage form of phosphorus (P) in cereal grains and phytic acid P accounts for 60~80% of total P in the cereal seeds. It chelates important minerals such as Zn2+, Fe3+, K+ and Ca2+ and virtually renders them indigestible by human and non-ruminant animals. In addition, phytic acid can also affect the absorption by humans of protein, starch and fat utilization. Therefore, PA is commonly regarded as the major anti-nurtitional component in cereal grains and can result in P pollution. Recently, germ plasm innovation and breeding of low phytic acid crops has opened a new approach to settle nutritional and environmental issues related with phytic acied.There were three focus in this research, they were to identify the low phytic acid material among 100 maize inbred lines from the Agricultural University of Hebei, to study the genetic mechanism of low phytic acid base on the lpa241, to improve the low phytic acid character between the inbred lines by backcrossing. The main results were as follows:1. Seeds from the 100 maize bred lines were indirectly screened by using the colorinmetric assay for high inorganic phosphorus (HIP). The result of screening was that most bred lines appeared yellow, that below the phosphorus level of 0.15μg/mg. It was possible to get the HIP, low phytic acid maize bred lines, because the screening of eight seeds tested from same material were consistent, but it was different among the different lines. By the further research, it appeared that Qi 319, Luyuan 92, Ji 853 were belong to the first level, for phytic acid content above 0.46μg, especially Qi 319 and Luyuan 92.2. The results of testing phytic acid P content of 100 inbred lines seeds by GB/T 17406-1998 showed that, the mean of phytic acid content in 100 inbred lines was 7.603mg/g, there was the maximum 10.645mg/g and the minimum 5.078mg/g among them, and the maximum was almost two times of the minimum. This showed that there were significant differences in phytic acid among them, and it was possible to find the material of low phytic acid, and got the low phytic acid inbred line 8401.3. Compared phytic acid content about the Qi319, Luyuan92, Qi319×Luyuan92, Luyuan92×Qi319, that came from follow seven different sources: Heilongjiang, Wuhan, Yangling, Tangshan, Shijianzhuang, Zhangjiakou, Baoding. The results showed that there were differences among the different places on the lines and their offspring. Perhaps it was related with the environment. 4. Harvesting the low phytic acid improvement lines by backcross, which as the parents of Luyuan92, Qi319, L/lpa241 and the parents lines of the key hybrid , such as Zheng58, Chang7-2, 9058, Xun92-8, X178, Huang C, P53, NongXi110. And mensurating the PA of the offspring of every generation.5. According to the screening results of F1 seeds between mutants(L/lpa241) and Qi319, Luyuan92, the HIP type and Wild type were segregative, respectively, which indicated the lpa character was controlled by single recessive genes. Allelism tests byχ2 test showed that the segregation of seedlings emergence fit into 3:1 about the F2 population between Qi319 and L/lpa241, it showed the Qi319 and the L/lpa241 was allelic. In addition, low phytic acid character was related to the form of the seed of lpa241.
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