摘要
西瓜是夏季的重要水果 ,病毒病是影响其品质和产量的重要原因之一。植物基因工程的发展为抗病育种提供了新途径。利用外壳蛋白 (coatprotein)基因转化高等植物 ,赋予转基因植物以相应抗病性的成功例子已很多。本文报道WMV - 2CP基因在转基因西瓜植株中的遗传、分离、表达以及转基因植株对病毒病的抗性实验结果。通过自交结合PCR检测 ,发现WMV - 2CP基因在自交子一代的分离符合孟德尔 3∶1的分离比。经过连续 4代的选择鉴定 ,已从T7、T11和T32 3个独立转化子的后代中筛选获得 8个转基因纯合株系 ,性状表现整齐一致。Westernblot结果表明 ,R4 T7-1、R4 T11-3以及R4 T32 -73个不同来源的株系均能表达产生外壳蛋白。转基因纯合株系WMV - 2感染后的病毒抗性实验表明 ,与未转基因对照相比 ,转基因株系可以推迟发病时间 ,减轻发病程度。实验筛选获得的转基因株系R4 T32 -7表现出对WMV - 2的高度抗性 。
Virus disease is a major cause that affects the quality and output of watermelon which is an important fruit in summer.So it is really urgent to develop disease resistance plants.But it takes a long time to breed such plants in conventional ways,and it is very difficult to get ideal result.With the development of plant genetic engineering,new ways have been found to breed plants with disease resistance.By using plant transgenic technique,much progress was been made in plant improvement.There are many successful cases of transgenic plants against corresponding virus disease through transferring coat protein gene.This paper reports the results of inheritance,segregation,expression of WMV-2 coat protein gene in inbred transgenic watermelon and its resistance to virus.Through PCR analysis of inbred plants,we found WMV-2 coat protein gene in the genome of progeny R 1 separated with 3∶1.After successive selection and identification of 4 generations, 8 transgenic pure lines with almost the same agronomic traits were obtained from 3 independent transformants of T 7,T 11 and T 32 .The result of Western blotting shows all 3 different transgenic lines of R 4T 7-1 ,R 4T 11-3 and R 4T 32-7 can produce coat protein.Disease resistance experiment on transgenic plants with WMV-2 shows that,compared with the control groups,transgenic plants can delay the disease infection and reduce the incidence and the symptoms of virus disease.And the transgenic line R 4T 32-7 expressed high resistance to infection by WMV-2,which lays a foundation for breeding of disease resistant varieties through plant transgenic technique.
基金
浙江省自然科学基金 (No .39310 5 )资助项目~~
