The revelation of genomic breed composition using target capture sequencing: a case of Taxodium

Taxodium plants have good flood tolerance and thus were introduced into China from North America in the early 1900s. The subsequent decades of cross-breeding experiments within Taxodium have produced many new hybrid cultivars in China while also creating confusion in the genetic background of Taxodium plants. In the present study, target capture sequencing-derived SNP markers were used to reveal the genomic composition of different species and cultivars of Taxodium. The results unraveled the phylogenetic relationship within Taxodium and suggested the possibility of recent interspecific natural hybridization events. The introduced (Chinese) population is genetically similar to the native (North American) population, thus providing genetic evidence for historical introductions of Taxodium. Hybrid categories of different cultivars of Taxodium hybrid 'Zhongshanshan' were further identified, and their differences in parentage were revealed. Collectively, the findings provide evidence for understanding the genetics and hybridization of Taxodium and shed light on the future breeding and cultivation of cultivars with great ecological and economic potential.