Invasive Fallopia x bohemica interspecific hybrids display different patterns in secondary metabolites

摘要

Plant secondary metabolites arc important traits that can benefit an invasive plant in /its new environment. In the case of rapid evolution in the invaded area, the chemical weapons of introduced plants may diversify, and novel combinations or extremeconcentrations of these secondary metabolites may be expressed. The pvasivc Fallopia species complex (F. japonica, F. sachalinensis, and the F. x bohemica interspecific hybrids) is a good model to assess how chemical traits can vary during post-introduction evolution. We analyzed and compared the composition' of secondary metabolite extracts in F. x bohemica hybrids and in the parental species grown in the introduced arca./HPLC-DAD profiles were obtained for each Fallopia species, and the main peaks ofthe H PLC chromatograms represent,phenolic compounds. Analyses based on secondary metabolite profiles showed that F x bohemica hybrids are "closer to F japonica. The F. x bohemica hybrids expressed the compound families described in F. japonica and F. sachalinensis, with quantitative variations between them. Hybrid chemical cocktails showed a diversification of chemical weapons. Furthermore, transgrcssive segregation was observed. Three dianthroncs were identified for the first time in a Fallopia species and were more highly expressed in F japonica and F x bohemica hybrids. These results suggest an evolution in the chemical traits of Fallopia taxa in invaded areas such that certain genotypes may well have acquired new chemical cocktails resulting frompost-introduction hybridizations.