Title: The chloroplast psbK-psbI intergenic region, a potential genetic marker for broad sectional relationships in Anthurium Authors
Submitted to: HortScience
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: August 6, 2014
Publication Date: N/A
Interpretive Summary: Numerous commercial cut flower and potted anthurium are hybrids or descend from hybrids between different Anthurium species from which novel horticultural and ornamental characters arose. There are few resources to identify the various Anthurium species from each other at the molecular level that might aid researchers and breeders in understanding their genetic relationships as well as verifying samples in plant collections. In this study, we developed a diagnostic tool to identify closely related Anthurium species based on polymerase chain reaction (PCR) amplification product sizes of a region of the chloroplast genome spanning the genes psbK and psbI. The psbK-psbI genetic marker was adapted from a DNA barcode originally developed for duckweed, a plant in the same family as Anthurium. The psbK-psbI genetic marker was tested on DNA extracted from a collection of preserved, dry leaf tissue of different Anthurium species obtained from botanical garden collections. The developed method for detecting broad species relationships among Anthurium represents a new tool to aid in identifying genetic origins of diversity important for the development of new cultivars as well as characterizing species and cultivars in Anthurium collections.
Technical Abstract: 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 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 utility of dried plant tissue banks as a genetic reference and information resource to support basic research as well as ornamental plant characterization and improvement.