Purple spire fusion gene and use thereof as visual selection marker gene in plant transgenic technology

The invention discloses a purple spire fusion gene and use thereof as a visual selection marker gene in plant transgenic technology. The arabidopsis spire specific promoter and tomato anthocyanin synthesis path regulator gene is utilized to construct the fusion gene which is named PL1 fusion gene, which has the nucleotide sequence shown in a sequence table 1. The fusion gene can be used as visual selection marker gene, replaces antibiotic resistance gene and other traditional selection marker genes in the plant transgenic technology, and selects transgenic plants by taking purple bud or spire as characteristics. Therefore, problems of food safety, environmental safety and the like possibly caused by the traditional selection marker genes in the plant gene engineering technique application process can be avoided, and defects of complicated steps, long experimental period, low deletion efficiency, species restriction and the like of the conventional method for obtaining antibiotic resistance marker-free transge