Identification and classification of cut-flower "Huangyinghua" using DNA marker techniques

Huangyinghua is a popular cut-flower in China, but it is unclear as to whether "Huangyinghua" is an invasive Solidago canadensis or not. The genetic relationship of a total of 45 samples of "Huangyinghua" with S. canadensis, and S. decurrens were investigated using AFLP technique so as to determine the identity of "Huangyinghua". Genomic DNA was digested with EcoRI and MseI enzymes and. amplified with six E+3 and M+3 primer combinations. AFLP analysis produced 661 endonucleotide discernable bands, of which 639 (96.61%) were polymorphic. Cluster analysis through using UPGMA method indicated that "Huangyinghua" and S. canadensis were clustered into the same group that was different from S. decurrens. Sequence analysis based on the ITS regions showed that their sequences of 5.8 S rDNA were the same, and the differences were found only in the ITS1 and ITS2 regions. ITS phylogenetic trees of the tested samples and closely-related species were reconstructed based on our sequence data in combination with those from GenBank. Based on the trees, "Huangyinghua" was found to belong to S. canadensis complex, but not to S. decurrens. Moreover, it was found that there were considerable genetic variation in both "Huangyinghua" and S. canadensis. Therefore, the cut-flower "Huangyinghua" may be invasive, and proper measures should be taken to control the further spread of its propagules.