A primer to the use of herbarium specimens in plant phylogenetics

摘要

As an important DNA source, herbarium specimens have been widely used in plant phylogenetics due to their easy accessibility and richness. However, contamination is a constant risk owing to low quality and/or quantity of DNA extracted from old samples. The inclusion of contaminant sequences can mislead phylogenetic reconstruction, and thereby affect subsequent analyses, such as divergence time estimates and biogeographic inferences. To employ appropriately herbarium specimens in plant phylogenetics, we outline here several suggestions regarding DNA extraction, PCR amplification and sequencing. We hope that these suggestions will serve as a guide for researchers using herbarium specimens in plant phylogenetics and help them identify from the early steps potential contaminant sequences from other plants or other organisms.