稗属植物DNA条形码研究

为评估DNA条形码在稗属植物鉴定中的有效性,选取核DNA条形码序列ITS和ETS及叶绿体DNA条形码序列psbA、trnL-F和matK作为候选序列进行了分析。本研究对无芒稗、稗、长芒稗和细叶旱稗4种稗属植物的不同DNA条形码序列进行了扩增、测序,并分析了不同候选条形码序列的特征。结果显示,matK序列变异位点占比最高(3.6%),ETS序列最低(1.7%);psbA序列种间变异最大,matK序列种内变异最大;邻接树分析显示,条形码序列ITS、ETS、psbA、trnL-F和matK均可以区分出长芒稗,支持率均大于80%;此外,ITS序列将无芒稗和稗聚于同一支,可以区分出细叶旱稗。因此,建议ITS作为鉴别稗属植物潜在的DNA条形码序列。

DNA Barcodes Study of Echinochloa

To evaluate the effectiveness of DNA barcodes in the identification of the genus Echinochloa, two candidate DNA barcodes from nuclear genome (ITS, ETS) and three candidate DNA barcodes from chloroplast genome (psbA, trnL-F, matK) were analyzed. The study amplified and sequenced the five candidate DNA barcodes from four Echinochloa species (E. crus-galli var. mitis, E. crus-galli var. crus-galli, E. caudate and E. crus-galli var. praticola), and analyzed the characteristics of each DNA barcode. The results show that matK has the highest proportion of variable sites (3.6%), and ETS has the lowest (1.7%); psbA has the largest interspecific distance, while matK has the largest intraspecific distance. The neighbor-joining (NJ) tree shows that all five candidate DNA barcodes have the ability to identify E. caudata, and their support rates are all higher than 80%. Furthermore, ITS could distinguish E. crus-galli var. praticola from E. crus-galli var. mitis and E. crus-galli var. crus-galli species. Therefore, it is recommended to use ITS as the potential DNA barcode for identifying Echinochloa.