Study On The Molecular Breeding Of Indica Rice With IPA1 Gene

Rice is one of the most important grain crops in the world. In recent years, with the world population increasing and farmland area decreasing, the demand for food is increasing and food security has become an increasingly serious problem. Plant type is a key factor to crop yield, so carrying out a series of related researches on rice ideotype have important practical significance.This study was designed to introduced IPA1 gene into indica restorer line "Ming hui 86" mediated with agrobacterium tumefaciens, expecting to select few tillers, strength stem, big spike and lodging lines from transgenic plants, achieving the purpose of the super high yield of rice. Aiming at this goal, the main conclusions were made as follows.1.Plasmid PHIMES-Ubi-IPA1 was introduced into indica restorer line "Minghui 86" by agrobacterium-mediated transformation, and 132 putative transgenic plants were obtained, the PCR results showed that the marker gene bar can be detected in 64 putative transgenic plants, preliminary indicating that the T-DNA with IPA1 gene had been integrated into indica restorer line "Minghui 86".2. The Southern blot analysis was performed for 5 plants from PCR-positive transgenic plants randomly, the result showed that three transgenic plants detected the signal (a single copy).3. The RT-PCR analysis was performed for 6 PCR-positive transgenic plants randomly, the results showed that a 436bp objective lane could be detected in all transgenic plants, indicating that the IPA1 gene in T-DNA was expressed in the mRN A level in transgenic plants.4. Expression of IPA1 gene were compared in transgenic plants and control plants with real-time PCR. The results showed that expression of IPA1 gene in most of the transgenic plant (roots, stems and leaves) were higher than control and the tissue expression of IPA1 special in "Minghui 86" were analyzed, indicated that the expression of stems was highest, followed by leaves, and the lowest of roots.5. Compared the physiological indexes of transgenic plants with the control rice, the results showed that the plant height, tiller number and internode length of transgenic plants were lower than the control, but the chlorophyll content were slightly higher than that of the control rice. Meanwhile indicated that the cellulose content, lignin content, potassium content and silicon content of transgenic plants were significantly greater than the control, but hemicellulose content were lower than that of the control rice.6. For genetic analysis of transformants, the leaves of T1 generation plants and T2 generation plants were soaked in solution with PPT and Hyg. And then this method was proved to be an useful method for genetic analysis of progeny by the correspondent PCR analysis.7. The culm cross section of transgenic plants were analyzed by SEM, the results showed that the fiber cell layers around small vascular bundle in transgenic plants were more than that of control plants, and sclerenchyma cell wall thickness and the degree of lignification were greater than that of control plants.