| Rapeseed (Brassica napus Z,.) is an important oilseed crop in China. At present, the cultivated area and gross production of rapeseed both occupy the first class in the world, while the unit production is far below that of some countries such as Canada and Europe. Some high production and good qulity cultivars were introduced from those contries, but most of them ripen later and growth period is longer, which becomes a hard problem to harmony between the decreasing arable land and alternative planting of other crops. This research aimed at ohJaraitig some new materials by plant genetic engineering. Based on ftis, FFFl gene from Arabidopsis was introduced into rapeseed to modify blooming date and growth period in order to obtain the previous excellent characters, pre-bloom and pre-ripen transgenic plants. The plants were characterized both in the field and at molecular level. The main results are as follows:1. Optimization of regeneration systems oi hypocotylsHypocotyls from 7 day-old seedlings of three cultivars were cut into 0.5-1 cm in length and screened repeatedly on MS containing different concentration BA and NAA. In according to growing well of callus, regeneration shoot frequency amounting to 80-90%, at least 2-4 shoots and short growing cycle, the optimum medium was MS supplying with 2.5mg/L BA and O.lmg/L NAA2. Optimization of A. tumefaciens-me&ated trasformation systems of hypocotylsHypocotyls were pre-cuhured on MS containing l.Omg/L 2,4-D and 0.2mg/L BA for 2~3d before infection via Agrobacterium. After quickly dipped into the Agrobacterium suspension of OD玱o 0.4 for 30~40s, the hypocotyls were co-cultured on the same medium covered with a sterile filter paper disc for 36~48h in darkness. When the co-culture was over, the explants were washed in liquid MS containing 500mg/L Cef for 30min to kill the overgrown Agrobacterium. Subsequently, the explants were transferred to the delay selection media containing 400mg/L Cef for 6~8d and subcultured on selection media containing lOmg/L Km. The obtained shoots were proliferated, rooted and transplanted.3. Analysis of Kanamycin-resistance of transgenic plants-m-Analysis of Kanamycin-resistance were conducted with ten lines from two cultivars during the rooting..phase. The results showed that most transgenic seedlings rooted normally. It suggested that NPT n gene have been integrated into rapeseed genome and had been expressed in most transgenic plants. It was hardly for negative plants to root normally and white wholely.4. Characteric of transgenic plants in the fieldTen transgenic plants of two cultivars and the negative control plants were transplanted into the field tor-observe the growth and development. The result showed that seven plants of 2000F4102 and five of:2000P232 bloomed earlier than the negative plants. In contrast with the negetive plants, the leaves of the transgenic plants were smaller, color deeper, less and the height was lower. While development of flower organ and fertility were almost in corresponding with the negative plants, which suggested FPFl gene have been integrated into rapeseed genome and had been expressed in transgenic plants.5. Effection of GA on FPFl gene expressing in the plantThe plants(containing transgenic and untransgenic plants) treated with 2.5mg/L GAa and the plants untreated were transplanted into the field meantime. The result observed showed that the treated transgenic plants with GAs bloomed earlier than the untreated, while the treated negative plants bloomed iit?r tnan tne untreated transgenic plants, which showed that GA might control the-expression of FPFl gene in the plant and effect on the blooming time of the plant.6. Molecular biology characteristic of transgenic plantsThe repeated PCR assay of twelve flowering promoting plants showed ttet seven transgenic plants got the same result with positive control, which proved NPT n gene had beer integrated into genome of rapeseed.After designing and synthesizing the primer according to Aralidcpsis FPFl gene sequence o...
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