New reports of nuclear DNA content for 66 traditional Chinese medicinal plant taxa in China

The amount of DNA in the unreplicated haploid nuclear genome (C-value) provides important information for genome biodiversity. Genome size is used in a strikingly wide variety of plant biological fields with both practical and biological significance. To extend previously published datasets on plant nuclear content and to compile information on the DNA content of traditional Chinese medicinal plants in China, flow cytometry (FCM) was used to estimate C-values of medicinal plants in Shaanxi province, China. A total of 80 medicinal plant species and vouchers were collected from locations across Shaanxi province in China. Nuclei were extracted from fresh leaves in one of two buffers, stained with fluorochrome propidium iodide (PI), and analyzed on a Guava flow cytometer to measure the position of the fluorescence peaks relative to those of an internal calibration standard. Replicate extractions, low coefficients of variation and comparisons with published C-values in the same and related species were used to confirm the accuracy and reliability of our results. Prime C-values for 66 medicinal plant taxa are provided for which no published data exist, comprising 66 angiosperms, one gymnosperm and one pteridophyte. C-values for 14 additional taxa where a genome size has previously been published are also provided. The prime values represent new reports for 27 genera (out of the 48 genera and 38 families sampled). These data provide the foundation to enable phylogenetic analysis of C-value variation and karyotype diversity in Chinese traditional medicinal plants and assist future analyses aimed at analyzing how C-values co-vary with effective components and functional traits in Chinese traditional medicinal plants.