A DNA Barcode Reference Library of Native Seed Plants in Chinese Dryland Regions.

Approximately 6.6 million km2 of China's territory consists of drylands at high desertification risk. Despite ecological vulnerability, these regions remain understudied in biodiversity research. DNA barcoding provides an efficient tool for rapid species identification, offering significant potential for biodiversity conservation and ecological surveys in drylands. However, comprehensive reference data for China's drylands are currently lacking, underscoring the urgent need for a reliable, extensive, and traceable DNA barcode reference library. To address this gap, we systematically surveyed plant diversity across nearly all Chinese drylands from 2013 to 2021. Our study documented 1,140 species, representing 434 genera, 76 families, and 29 orders. Based on this effort, we constructed the most comprehensive DNA barcode reference library for native dryland seed plants in China, comprising 13,246 sequences across five markers: rbcL (3,056), matK (3,332), ITS (3,358), psbA-trnH (1,770), and trnL-F (1,730). This resource establishes a critical foundation for integrated taxonomic research, biodiversity monitoring, and environmental impact assessments. Moreover, it supports initiatives in desertification control, plant conservation, and sustainable development in China's dryland regions.