The Chloroplast psbK-psbI Intergenic Region, a potential genetic marker for broad sectional relationships in Anthurium

Nuclear and chloroplast genetic markers have been extensively used for plant identification and molecular taxonomy studies. The efficacy of genetic markers to be used as DNA barcodes is under constant evaluation and improvement with identification of new barcodes that provide greater resolution and efficiency of amplification for specific species groups as well as distantly related plants. In this study, chloroplast DNA genetic markers for Anthurium, the largest genus in the Araceae family, were adapted from chloroplast markers previously designed for Lemna minor, a member of the same plant family.

Primers for chloroplast region trnH-psbA, previously used for molecular systematic studies in Anthurium, as well as primers for the rpoB, rpoC1, psbK-psbI, matK, rbcL, and atpF-atpH regions, all located within the large single copy sequence in the chloroplast genome, were evaluated and found to efficiently amplify target sequences when using DNA of varied quality and concentration extracted from silica-dried leaves of selected accessioned species of Anthurium. The trnH-psbA, psbK-psbI, and atpF-atpH intergenic region primers were further evaluated using Anthurium species spanning different subgeneric groups. Of the intergenic region primers tested, psbK-psbI primers were the most robust, yielding well-defined amplicons across Anthurium species that were consistent, with exceptions, within sectional groupings.

Application of the psbK-psbI region amplicon as a visual marker for surveying sectional relationships in Anthurium is novel and serves as a model for the development of a diagnostic method for genotyping plants and testing for sample integrity from among species or germplasm collections. This work further demonstrates the use of dried plant tissue banks as a genetic reference and information resource to support basic research as well as ornamental plant characterization and improvement.

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