摘要：

为分析陆地棉一个低毒Bt基因转化事件的特点,采用特异引物对该Bt基因进行鉴定。结果表明,该Bt基因片段大小拟合美国 Bt 抗虫基因设计引物的特征片段长度 310 bp,显示该种质系所含的Bt基因为美国抗虫基因。利用该种质系与海岛棉胜利1号配置杂交组合,其杂交F₁中Bt基因呈显性表达,分离F₂群体中有Bt、无Bt基因个体数拟合3∶1的理论分离比例,结果显示,该Bt基因是受1对显性基因控制的质量性状,即该外源基因以单位点方式插入陆地棉受体。而后采用海陆杂交F₂群体,以SSR分子标记对低毒Bt基因进行染色体定位,结果显示,它位于棉花第10号染色体上,共有14对引物与目的基因相连锁,分别是SSR标记NAU5166、NAU3574、NAU456、BNL256、cgr6745、cgr5406、cgr6546、NAU7110、HAU3201、BNL1665、dPL0468、NAU5316、BNL2960、NAU3122。Bt基因位于分子标记NAU7110和HAU3201之间,其遗传距离分别为0.9,4.4 cM。

关键词: 陆地棉, 低毒Bt基因, 分子鉴定, 基因定位

Abstract:

In order to analyze a transgenic event of an upland cotton germplasm strain with low expression of a Bt gene,specific primers were used to identify the Bt gene.The PCR amplification result showed a fragment length of the Bt gene was 310 bp,which conformed characteristic primer fragment length to Bt gene of the United States.Using the germplasm strain to cross with island cotton Shengli No.1 showed that the Bt gene was dominant in F₁,and Bt-harboring plants to non-harboring plants displayed a 3∶1 segregation ratio in F₂ population.The result proved that the Bt gene was a quality trait controlled by a pair of dominant gene,which meant the foreign Bt gene was inserted into upland cotton as a locus.Furthermore,F₂ population and SSR markers were used in the gene mapping.The result revealed that the Bt gene was mapped on the 10th chromosome of cotton,and 14 pairs of primers were linked to the target gene,such as NAU5166,NAU3574,NAU456,BNL256,cgr6745,cgr5406,cgr6546,NAU7110,HAU3201,BNL1665,dPL0468,NAU5316,BNL2960,NAU3122.The Bt gene was located between the molecular markers NAU7110 and HAU3201,and its genetic distance was 0.9,4.4 cM,respectively.

Key words: Upland cotton, Low-toxic Bt gene, Molecular identification, Gene mapping