The southern varieties of the American eelgrass, Vallisneria americana, are vital contributors to aquatic ecosystems throughout Florida and other areas within the southeastern United States. Recent discovery of cryptic non-native Vallisneria in natural waterbodies of central and southeast Florida has raised concerns for the biosecurity of native American eelgrass populations, which have been lost from many historical locations and are the subject of multiple, intensive restoration/reintroduction efforts throughout the state. The non-native grasses were found to be derivatives of a hybrid V. spiralis × V. denseserrulata, which is ubiquitous within the global aquarium trade and represents a worldwide invasive threat. Concern for the native taxon and difficulties in visually distinguishing it from non-native taxa prompted the development of a molecular screening assay. The method leverages parsimony-informative insertion/deletion-based variation within a fluorescently labeled amplified segment of the nuclear ribosomal internal transcribed spacer region. Based on comparisons to sequenced specimens (n = 96), fragment length polymorphisms for the amplicon, visualized by capillary electrophoresis, reliably diagnosed the Florida non-native grasses with 100% accuracy, sensitivity, and specificity. With additional ground-truthing to confirm intraspecific stability, this assay has the potential for broader application within the genus, including detection of the invasive V. australis (cf. V. gigantea), another ubiquitous aquarium product, as well as identification of first-generation hybrid forms.

美国苦草的南部品种，美洲苦草，是佛罗里达州和美国东南部其他地区水生生态系统的重要贡献者。最近在佛罗里达州中部和东南部的自然水体中发现了神秘的非本土苦草，引起了人们对美洲本土鳗草种群生物安全的担忧，这些鳗草种群已经从许多历史地点消失，并且是整个美国多次密集的恢复/重新引入工作的主题。状态。这些非本地草被发现是V.spiralis  ×  V.denseserrulata杂交品种的衍生物，它在全球水族箱贸易中无处不在，是一种全球性的入侵威胁。对本地分类单元的关注以及在视觉上将其与非本地分类单元区分的困难促使分子筛选测定的发展。该方法利用核核糖体内部转录间隔区荧光标记扩增片段内基于简约信息插入/删除的变异。基于与测序样本 (n = 96) 的比较，通过毛细管电泳可视化的扩增子片段长度多态性，以 100% 的准确性、敏感性和特异性可靠地诊断了佛罗里达州非本地草。通过额外的地面实况来确认种内稳定性，该测定有可能在该属内得到更广泛的应用，包括检测侵入性细菌V. australis（参见V. gigantea），另一种普遍存在的水族馆产品，以及第一代杂交形式的鉴定。