Narisa Juejun, Chataporn Chunwongse, and Julapark Chunwongse

pp. 149 - 158

Abstract

Public databases are useful for molecular marker development. The major aim of this study was to develop expressed
sequence tag (EST)-derived markers in Dendrobium from available ESTs of Phalaenopsis and Dendrobium. A total of 6063
sequences were screened for simple sequence repeats (SSRs) and introns. Primers flanking these regions were generated and
tested on genomic DNAs of Phalaenopsis and Dendrobium. Twenty-three percent of amplifiable Phalaenopsis EST-derived
markers were cross-genera transferable to Dendrobium. Forty-one markers from both Phalaenopsis and Dendrobium that
amplified in Dendrobium were assessed on six commercial cultivars and six wild accessions. All of them were transferable
among Dendrobium species. High polymorphism and heterozygosity were observed within wild accessions. Sixteen polymorphic markers were evaluated for linkage analysis on an F1
 segregating population. Seven markers were mapped into three
linkage groups, two of which showed syntenic relationship between dendrobium and rice. This relationship will facilitate
further quantitative trait loci (QTL) mapping and comparative genomic studies of Dendrobium. Our results indicate that
Phalaenopsis EST-derived markers are valuable tools for genetic research and breeding applications in Dendrobium.