基于DNA条形码鉴别青葙子及其混伪品绿穗苋种子

Identification of Seeds of Celosia argentea L.and its Adulterants Seeds of Amaranthus hybridus L.Based on DNA Barcoding

目的:基于DNA条形码对青葙子、绿穗苋种子进行鉴定。方法:基于ITS2、psbA-trnH、matK、rbcL常用DNA条形码的通用引物对样品进行扩增、测序,并从NCBI数据库下载ITS2、psbA-trnH、matK、rbcL碱基序列。利用MEGA 11.0软件构建NJ系统发育树、计算遗传距离及比较种间差异,并基于ITS2序列构建二级结构。结果:基于上述序列构建的NJ树均独立聚为一支,其中ITS2的种间遗传距离最大,基于ITS2构建的二级结构具有明显差异。结论:基于DNA条形码ITS2碱基序列及其二级结构可准确鉴别出青葙子及其混伪品绿穗苋种子,psbA-trnH碱基序列可以作为辅助鉴别序列。

Objective:Identification of seeds of Celosia argentea L.and Amaranthus hybridus L.based on DNA barcoding.Methods:The samples are amplified and sequenced based on the universal primers of ITS2,psbA-trnH,matK,and rbcL commonly used DNA barcodes,and the nucleotide sequences of ITS2,psbA-trnH,matK,and rbcL are downloaded from the NCBI database.The MEGA 11.0 software is utilized to construct NJ phylogenetic trees,calculate genetic distances,and compare interspecific differences,and the secondary structure is constructed based on the ITS2 sequence.Results:The NJ trees constructed based on the sequence independently clustered into a single branch,in which ITS2 exhibites the largest interspecific genetic distance,and the secondary structure constructed based on ITS2 shows significant differences.Conclusion:Based on DNA barcoding and the secondary structure of ITS2,it's possible to accurately identify the seeds of C.argentea and its mixed pseudo seeds of A.hybridus,and the psbA-trnH base sequence could be used as an auxiliary identification sequence.