中文摘要：

【目的】甜菜是重要的糖料作物,块根中的蔗糖含量是其品质的决定因子。利用基因工程技术将葡萄蔗糖转运蛋白基因（VvSUC11和VvSUC12）导入甜菜块根中,以了解蔗糖转运蛋白是否能提高甜菜的含糖量。【方法】利用葡萄蔗糖转运蛋白基因VvSUC11和VvSUC12构建的根特异性表达植物双价表达载体（pCAMBIA2301-SP1-VvSUC11-SP2-VvSUC12）,通过农杆菌介导法转化到甜菜（Beta vulgaris L.）品种KWS-9103中。利用PCR和RT-PCR技术检测目的基因是否整合到甜菜中并表达。将获得的转基因甜菜和对照甜菜生根后移栽大田,对其叶片性状、相关的生理指标、块根重和含糖量进行测定。【结果】通过PCR和RT-PCR检测,获得13株转基因甜菜。测得转基因植株叶长、叶宽、叶柄长和叶片数量平均分别为25.16 cm、19.31 cm、29.17 cm和38.33个,与对照相比,叶宽增加31.81%,叶柄缩短16.61%,叶片数目增加17.04%,都存在极显著差异,而叶长增加1.68%,无显著差异；叶绿素a含量（1.31 mg·g-1）、叶绿素b含量（0.562 mg·g-1）和叶绿素总含量（1.87 mg·g-1）与对照无显著差异；叶中可溶性糖含量（14.59 mg·g-1）降低13.04%,与对照（16.51 mg·g-1）存在极显著差异,叶柄中可溶性糖含量（21.90 mg·g-1）增加3.36%,但与对照（21.6 mg·g-1）差异不显著；单株转基因甜菜的块根重和含糖量分别平均为3.067 kg和183.2 g·kg-1,与对照（2.894 kg）相比,块根增重5.91%,差异不显著,含糖量增加9.41%,与对照（167.5 g·kg-1）存在显著差异。说明转基因甜菜叶面积和叶片数的增加,扩大了其光合叶面积,同时叶柄缩短有利于提高糖分子从源叶到库的转运,促进甜菜块根的形成和加快糖分的积累。【结论】利用蔗糖转运蛋白VvSUC11、VvSUC12能够有效地提高转基因甜菜的含糖量。

英文摘要：

【Objective】Sugar beet is an important sugar crop in the world. The sucrose content in roots is the key determinant of sugar beet quality. In order to study the improvement of saccharinity of sugar beet by two sucrose transporter genes from grape, VvSUC11 and VvSUC12, were introduced into sugar beet root using plant genetic engineering. The work will lay a foundation for using sucrose transporter genes to increase crop yield and quality. 【Method】 A bivalent root specific expression vector called pCAMBIA2301-SP1-VvSUC11-SP2-VvSUC12 containing grape sucrose transporters VvSUC11 and VvSUC12 genes was constructed and transformed into sugar beet variety KWS-9103 by Agrobacterium tumefaciens mediated transformation. Then PCR and RT-PCR analyses were used to confirm the integration and expression of the two genes in transgenic sugar beets. The leaf characters, physiological targets, tuberous root weight and saccharinity of transgenic and control plants were measured after transplanting to the field.【Result】Thirteen transgenic sugar beet lines were obtained by PCR and RT-PCR analyses. Results indicated that the average number of leaf width, petiole length and leaf number of transgenic plants were 19.31 cm, 29.17 cm and 38.33, which increased obviously by 31.81%, 16.61% and, 17.04%, respectively, the average number of leaf length were 25.16 cm, which increased insignificantly by 1.68%. However, there were no significant difference in the content of Chlorophyll a（1.31 mg·g-1）, Chlorophyll b（0.562 mg·g-1） and total Chlorophyll（1.87 mg·g-1） between transgenic and control plants. Compared to control, soluble sugar content（14.59 mg·g-1） of leaf was reduced markedly by 13.04%, but soluble sugar content（21.90 mg·g-1） of petiole was only increased by 3.36%. The average root weight and sugar content of individual plants were 3.067 kg and 183.2 g·kg-1, respectively. Compared with control plants, the root weight of transgenic plants increased by 5.91%, while saccharinity increased significantly b