Chloroplast DNA molecular characterization and leaf volatiles analysis of mint (Mentha; Lamiaceae) populations in China

Non-coding chloroplast DNA (cpDNA) was used to evaluate genetic diversity and relationships within the section Mentha collected from China. Leaf volatiles of Mentha spicata accessions and its parent were analyzed by gas chromatography (GC) and gas chromatography-mass spectrometry (GC-MS). To this end, genetic diversity of 30 Mentha accessions from different geographic origins of China, representing six species and two hybrids, was assessed. Molecular studies grouped the samples mainly according to genetic relationship established by conventional methods. Cluster analysis based on the leaf volatiles chemical composition of M. spicata accessions defined two main chemotypes: 1,8-cineole-piperitenone oxide type and limonene-carvone type. The results suggested that there was a high genetic variability among individuals of Mentha in China. A distinct correlation between cpDNA marker and volatile oils in M. spicata accessions was revealed. Moreover, the chemical composition followed maternal inheritance in M. spicata accessions. In conclusion, the genetic diversity of Mentha populations as shown in this study should play a critical role in future selection and breeding programs.