Transforming Parent Lines Of Hybrid Rice With Anti-sense Waxy Gene

In this thesis, anti-sense Waxy gene was transformed into the calli of hybrid rice parent lines, meanwhile the factors influencing the rate of transformation were studied. The results are as follows:Young panicles and young embryos are preferable explants for tissue culture, but they are only available in the growing seasons. Mature embryos have many advantages over young embryos, such as higher frequency and shorter period of regeneration, easier availability, etc. The culture ability of mature embryos is lower than young embryos, however this disadvantage can be improved by adding exogenous plant growth substances or other additives.The indica rice Teqing (Oryza Sativa L. subsp. indica) and japonica rice Guangjing No.1 (Oryza Sativa L. subsp. japonica) were transformed by p13w4 plasmid which carrying anti-sense waxy gene and hygromycin-resistant gene. At the same time,some indica rice varieties were co-transformed by p13w8 plasmids carrying waxy gene and p1300 plasmids carrying hygromycin-resistant gene. Some transgenic regenerative plants were successfully obtained. PCR analysis showed that the marker gene and target gene had been transformed into the genome of most transgenic plants. Most of the T0 and T1 transgenic plants could produce seeds normally. PCR analysis showed that target gene had been segregated in the T1 progenies. Detailed analysis showed that some transgenic plants which had been transformed only with the target gene into the genome without the marker gene.In the process of rice genetic transformation, the levels and changes of endogenous phytohormones affect calli's physiological status. IAA was found to be more abundant in the callus buds than in the mature embryos. High content of IAA reduced callus induction and growth. In fact, GA affects callus growth by interacting with IAA. High contents of IAA and GA could promote the callus growth and multiplication while low contents of IAA and GA enhanced callus differentiation. Z was found to be mainly existed in seed embroys, being crucial for callus induction. Calli could not be induced when Z content was too low, even both IAA and GA levels were relatively high. High content of ABA was negative to callus induction, but might increase embryogenic callus in the process of callus regeneration.The content of amylose in the endosperm of mature seeds had been measured. The results showed the content of amylose of the transgenic plants was lower than that of the control, and some of the transgenic plants' content of amylose were less than 10.0%, which are much lower than that of the control (about 22.0%).