| Chinese kale (Brassica oleracea var.alboglabra) does not only contain special flavor and high nutritional value, but also include plenty of biological activity substance. Thioglycoside rich in the leaves can change into sulforaphen that is the most effective anticarcinogen in comparison with other vegetables nowadays. Chinese kale is one of the most important export vegetables too.High yield is one of three objects about crop breeding. Extracting and transforming high-yield gene can be an effective method to increase crop output.Flower-controlling gene C220 was delayed and the biological yield and seed yield greatly increased when the gene was deleted in Arabidopsis.We optimized the gene transformation system mediated by Agrobacterium, and inhibited the gene expression with RNA interference technology so as to cultivate new high-yield Chinese kale. Then we invested the phenotype of transgenic plantlets. Main results:1,An efficient genetic transformation system of B.oleracea var. alboglabra mediated by Agrobacterium tumefaciens was established, with Orthogonal Design, by optimizing the concentration of Kan, Carb, AgNO3 and the infection time of Agrobacterium tumefacien. Results showed that the concentration of Kan, Carb, AgNO3 and the infection time of Agrobacterium tumefacien had noticeable effect on the regeneration frequency of KanR planets. The efficient infection time of Agrobacterium tumefacien was 8min, the concentration of Kan was 5mg/L, the concentration of Carb was 400mg/L, and the concentration of AgNO3 had little influence.2,According to the efficient gene transformation system above, expression RNAi vector pK7GWIWG2-BNC220 was transferred into Chinese kale (Brassica oleracea var.alboglabra cv. Zhonghua) mediated by Agrobacterium MP90. 20 transgenic plantlets were obtained in the research. Among them 9 were confirmed to be positive transformants by PCR verification. The frequency of positive transformant of KanR seedlings of B.oleracea var. alboglabra was 45﹪.3,Invest the leaf number, the leaf area (length×wide), the stem nodes and the bolting time of transgenic planets with the control of wildtype. Phenotype investigation indicated that the leaf number, the leaf area (length×wide) increased greatly. The leaf number of transgenic plants was increase 45﹪over wildtype; the leaf area of the transgenic plants was 272.40cm2 on average, an increase of 91.52﹪over wildtype; the stem nodes of the transgenic plants was 14.47mm on average, an decrease 58.52﹪over wildtype; the bolting time was 14d later than that of the wildtype, an increase of 32﹪. The results above indicated that C220 had been transformed into Chinese kale with RNA interference technology and the method was beneficial to increase the biological yield. |
