Development of a New Rose (Rosa hybrida) Cultivar and Single Nucleotide Polymorphism Markers for Cultivar Identification

Abstract

The main objectives of this study were to develop a new rose cultivar and to develop single nucleotide polymorphism (SNP) markers to identify cultivars. A new cultivar, To Dios having numerous petals was bred as a cut flower type from the progeny of a cross between Vanilla Perfume and Marcia. An orange-colored standard rose cultivar Vanilla Perfume with 48 petals was used as a female plant. A white-colored standard rose cultivar Marcia with 96 petals was used as a male parent. To Dios is a standard type with 128 peach-colored petals per flower. The vase life of To Dios cultivar can be as long as 15 days. To Dios has the functional stomata in both light and dark conditions, and appropriate stomatal closing helped it to maintain water balance. It takes 47 days from pruning to re-blooming and cut flower productivity is about 160 stems /m2 in a year. When temperature was low, the petal numbers of To Dios was increased and the stamens were converted to petals. To Dios was registered as a new cultivar on Korea Seed & Variety Service in 2014. Since variety protection is important, SNP markers to identify new developed rose cultivars including To Dios were developed. The advantage of SNPs was used to develop a method for identification of cultivars of the polyploid Rosa hybrida using genotyping-by-sequencing (GBS). Sequences obtained from GBS libraries of the genomes of 79 roses were aligned to contigs created by de novo assembly, due to lack of rose reference genome. A total of 1,778 SNPs were selected from 13,488 putative SNPs, genetic correlations among rose cultivars were efficiently analyzed by using these SNPs. SNP markers presented in more than 70% of the 79 cultivars were selected and evaluated, both for polymorphism information content values and level of heterozygosity, and then 20 SNP markers were ultimately selected for high-throughput analysis. Of these 20 SNP markers, 4 were successfully converted into markers for DNA chip assays. High resolution melting analysis was carried out to distinguish further rose genotypes, dependent on heterozygosity and polyploidy. As a result, using a 7 SNP marker set, I was able to discriminate 70.9% of the 79 rose cultivars, and 87.5% of the 16 new cultivars including To Dios developed in Goyang City. SNP markers developed in this study will be useful tools for cultivar identification and genetic correlation study in rose cultivars.