Genetic Variation and Genomic Constitution in The Spatulata Orchid Hybrids (Dendrobium spp.) Derived from Interspecific Hybridization Using SRAP marker

Abstract

Dendrobium is the second largest genus in the Orchidaceae family. Dendrobium section Spatulata is widely cultivated in Indonesia due to its ease of cultivation, high economic value and adaptability, and extended flower shelf life. In this study, we have conducted a breeding program for developing new cultivar of Dendrobium section Spatulata through interspecific hybridization. This study is aimed to investigate the genetic variation and genomic constitution of the eight hybrids and their corresponding parental lines resulted from interspecific hybridization using SRAP markers. Dendrobium section Spatulata hybrids produced by interspecific hybridization are genuine hybrids with substantial genetic variability based on flower morphology, including labellum shapes and color intensities, as well as curly horn shapes and color intensities. The SRAP marker, which was utilized to genotype the hybrid and parental lines, exhibited a significant degree of polymorphism, and may be used to distinguish each accession. The UPGMA dendrogram and PCoA biplot showed that all the hybrids were grouped with their corresponding parental lines based on their genetic background and genomic constitution. These findings are critical for genetic improvement of the Spatulata orchid to develop novel varieties.