Insights into the Genomic Background of Nine Common Chinese Medicinal Plants by Flow Cytometry and Genome Survey

Medicinal plants have long played a crucial role in healthcare systems, but limited genomic information on these species has impeded the integration of modern biological technologies into medicinal plant research. In this study, we selected nine common medicinal plants, each belonging to a different plant family, including <i>Sarcandra glabra</i> (Chloranthaceae), <i>Nekemias grossedentata</i> (Vitaceae), <i>Uraria crinita</i> (Fabaceae), <i>Gynostemma pentaphyllum</i> (Cucurbitaceae), <i>Reynoutria japonica</i> (Polygonaceae), <i>Pseudostellaria heterophylla</i> (Caryophyllaceae), <i>Morinda officinalis</i> (Rubiaceae), <i>Vitex rotundifolia</i> (Lamiaceae), and <i>Gynura formosana</i> (Asteraceae), to estimate their genome sizes and conduct preliminary genomic surveys. The estimated genome sizes by flow cytometry were 3.66 Gb, 0.65 Gb, 0.58 Gb, 1.02 Gb, 3.96 Gb, 2.99 Gb, 0.43 Gb, 0.78 Gb, and 7.27 Gb, respectively. The genome sizes of <i>M. officinalis</i>, <i>R. japonica</i>, and <i>G. pentaphyllum</i> have been previously reported. Comparative analyses suggest that variations in genome size may arise due to differences in measurement methods and sample sources. Therefore, employing multiple approaches to assess genome size is necessary to provide more reliable information for further genomic research. Based on the genome survey, species with considerable genome size variation or polyploidy, such as <i>G. pentaphyllum</i>, should undergo a ploidy analysis in conjunction with population genomics studies to elucidate the development of the diversified genome size. Additionally, a genome survey of <i>U. crinita</i>, a medicinal plant with a relatively small genome size (509.08 Mb) and of considerable interest in southern China, revealed a low heterozygosity rate (0.382%) and moderate repeat content (51.24%). Given the limited research costs, this species represents a suitable candidate for further genomic studies on Leguminous medicinal plants characteristic of southern China. This foundational genomic information will serve as a critical reference for the sustainable development and utilization of these medicinal plants.