基于紫皮石斛叶绿体基因组遗传变异的品种鉴定标记开发OA

Objective To elucidate the chloroplast genome structure and genetic variation of two Dendrobium devonianum Paxton cultivars called"Ziyu"and"Cuiyu",and develop molecular markers for reliable identification,thereby supporting germplasm conservation and industrial development.Methods Six samples from the two cultivars were sequenced using the Illumina NovaSeq platform,chloroplast genomes were assembled and annotated with GetOrganelle and CPGAVAS2;mVISTA was used to screen the highly variable regions of the chloroplast genome,specific primers were designed,and PCR amplification,electrophoresis and sequencing were employed to verify the identification effect.Results The complete chloroplast genomes of"Ziyu"and"Cuiyu"were 157115 and 156632 bp in length,respectively,both exhibiting a typical quadripartite structure.And each genome contained 119 annotated genes,with a GC content of 37.5%.A total of 46 and 41 SSRs loci were detected,predominantly composed of A/T repeats.Sequence variations were mainly concentrated in non-coding regions and the LSC/SSC regions,resulting in the identification of six highly variable regions.A primer pair(D5)targeting the trnI-CAU-trnL-CAA region enabled cultivar discrimination through a 38 bp InDel within the 100-137 bp segment,achieving a 100%amplification success rate.Conclusion This study clarifies the structural features and genetic differences of the chloroplast genomes of"Ziyu"and"Cuiyu".The developed molecular marker exhibits high stability and identification efficacy.These findings provide a robust molecular tool for D.devonianum cultivar authentication,germplasm conservation,and protection of cultivar rights.