Analyses of genetic diversity and relationships in four Calanthe taxa native to Korea using AFLP markers

Abstract

About 171 Calanthe species have been reported worldwide. However, only four species and two natural hybrids are known to grow naturally in South Korea. Classification studies of Calanthe orchids using molecular markers have been relatively limited. Therefore, the objectives of this study are to analyze the genetic diversity and relationships of four Calanthe taxa (101 accessions), including C. sieboldii (13 accessions), C. discolor (33), C. × bicolor (54), and C. aristulifera (1), native to South Korea and to identify the potential of each primer combination to discriminate each Calanthe accession using an AFLP technique. Thirty-two AFLP primer pairs produced a total of 2,764 bands, with an average of 86.4 bands per primer pair. Among all bands, 42.3% (1,354 bands), 51.6% (1,652), and 70.0% (2,240) were polymorphic in C. sieboldii, C. discolor, and C. × bicolor, respectively. Calanthe aristulifera was the most distant of the Calanthe taxa, and C. × bicolor, a natural hybrid of C. discolor × C. sieboldii, was more closely related to C. discolor (0.015 of genetic distance) than to C. sieboldii (0.022). Each Calanthe taxon with multiple accessions was divided into two or three groups. Comparisons of gene diversity, polymorphic information content, effective multiplex ratio, marker index, and resolving power proved that resolving power had the best discrimination potential for the 101 Calanthe accessions. These results will help to identify diverse accessions and to develop a breeding program of Calanthe orchids.