Chinese herbal tea, also known as Liang Cha or cooling beverage, is popular in South China. It is regarded as a quick-fix remedy to relieve minor health problems. Hedyotis diffusa Willd. (colloquially Baihuasheshecao) is a common ingredient of cooling beverages. H. diffusa is also used to treat cancer and bacterial infections. Owing to the high demand for H. diffusa, two common adulterants, Hedyotis brachypoda (DC.) Sivar and Biju (colloquially Nidingjingcao) and Hedyotis corymbosa (L.) Lam. (colloquially Shuixiancao), are commonly encountered in the market. Owing to the close similarity of their morphological characteristics, it is difficult to differentiate them. Here, we sequenced the complete chloroplast genomes of the three species of Hedyotis using next-generation sequencing (NGS). By comparing the complete chloroplast genomes, we found that they are closely related in the subfamily Rubioideae. We also discovered that there are significant differences in the number and repeating motifs of microsatellites and complex repeats and revealed three divergent hotspots, rps16-trnQ intergenic spacer, ndhD and ycf1. By using these species-specific sequences, we propose new DNA barcoding markers for the authentication of H. diffusa and its two common adulterants.

中文翻译：

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基于叶绿体基因组测序和DNA条形码标记的白花蛇舌草和常见掺假物的鉴别

中草药茶，也称为凉茶或凉爽饮料，在华南地区很流行。它被认为是缓解轻微健康问题的快速解决方案。白花蛇舌草。（俗称“百花蛇舌草”）是清凉饮料的常见成分。白花蛇舌草还用于治疗癌症和细菌感染。由于对白花蛇舌草的需求量很大，所以有两种常见的掺假品，即Hedyotis brachypoda（DC。）Sivar和Biju（俗称Nidingjingcao）和Codymbosa Hedyotis（L.）林 （俗称水仙草），是市场上常见的。由于它们的形态特征非常相似，因此很难区分它们。在这里，我们使用下一代测序技术（NGS）对3种萱草的完整叶绿体基因组进行了测序。通过比较完整的叶绿体基因组，我们发现它们在茜草科亚科中密切相关。我们还发现，微卫星和复杂重复的数量和重复基序存在显着差异，并揭示了三个不同的热点，rps16-trnQ基因间隔子，ndhD和ycf1。。通过使用这些物种特定的序列，我们提出了新的DNA条形码标记，用于鉴别白花蛇舌草及其两个常见的掺假物。