Male sterility is used to mass-produce F1 hybrid seeds in pepper (Capsicum annuum L.). In particular, the development of genetic male sterility (GMS)-linked molecular markers may play a crucial role in hybrid breeding of pepper. To date, approximately 20 GMS genes have been identified in pepper. Among these, several molecular markers for the ms3 gene have been developed in previous studies; however, they are not completely linked and thus have limitations for use in selection. Therefore, in the present study, we aimed to develop molecular markers for ms3 selection using single-nucleotide polymorphism (SNP)-based high-resolution melting (HRM) analysis. Chi-square test was conducted using three F2 segregating populations, and the results confirmed a 3:1 segregation ratio between male-fertile and male-sterile plants. A total of 128 primer sets were designed by selecting SNPs near the ms3 gene, and 25 HRM markers were successfully developed. Using 420 individuals from the F2 segregating population ‘GMS3,’ a high-density genetic linkage map of pepper chromosome 1 was constructed, with eight HRM markers found to be co-segregated with the ms3 gene. Subsequent experiments using various plant materials validated these eight markers, ultimately identifying two HRM markers, HRM119655681 and HRM135273656, for the final selection. These two markers showed co-segregation between the phenotype and genotype of ms3 across all plant materials used in the study. The markers developed in this study are expected to be effective for maternal line development and large-scale F1 hybrid seed production using ms3 in pepper.
Grape (Vitis vinifera L.) is a perennial fruit tree with high heterozygosity, consisting of 38 chromosomes (2n=38), and it takes a long time for grape seedlings to grow into fruit-bearing trees. Therefore, it is difficult to study grape genetics and breeding strategies. However, it has recently become possible to discover many SNPs through whole genome resequencing or genotyping-by-sequencing (GBS) analysis. In this study, we aimed to develop high-resolution melting (HRM) markers from the detected SNPs and construct a genetic linkage map using HRM markers. In a previous study, 2,553 SNPs were identified using GBS analysis. In this study, 1,336 SNPs were used to design primer sets for HRM analysis. The developed HRM markers were used for construction of a genetic linkage map in an F1 segregating population consisting of 192 individuals from a cross between ‘Tano Red’ (V. labrusca×V. vinifera) and ‘Ruby Seedless’ (V. vinifera). A total of 805 polymorphic HRM markers were developed, of which 363 were mapped onto the genetic linkage map of grape, with a total length of 1,453.5 cM consisting of 19 chromosomes. This SNP-based genetic linkage map and HRM markers can be used for QTL identification and marker development for important fruit traits of grape.
The bulb onion (Allium cepa L.), one of the most important vegetables worldwide, contains various functional compounds such as quercetin, allicin, and flavonoids. Red onions are rich in anthocyanins, a flavonoid that is a functional phytochemical with antioxidative and anticancer activities. In the previous study, two quantitative trait loci (QTLs) (qAC4.1 and qAC4.2) controlling the anthocyanin content were identified on chromosome 4 in an F2 population derived from a cross between A. cepa ‘SP3B’ and ‘H6’. In this study, we developed single nucleotide polymorphism-based high-resolution melting (HRM) markers linked to QTLs qAC4.1 and qAC4.2. In addition, we constructed a new genetic linkage map of chromosome 4 using HRM markers and performed a QTL analysis. The QTL qAC4.1 was false, while qAC4.2 was a major QTL. The QTL peak position, logarithm of the odds value, and phenotypic variance explained of qAC4.2 was 53.6 cM, 7.45, and 22.51%, respectively. Four HRM markers (AC4.2_65336.1_1123-HRM, AC4.2_53230.3_454-HRM, AC4.2_11999.1_756-HRM, and AC4.2_14596.1_345-HRM) within the QTL region of qAC4.2 were developed in this study. The average anthocyanin content of B (homozygous paternal) genotypes was higher than that of A (homozygous maternal) and H (heterozygous) genotypes for all markers. Consequently, these markers will be useful for marker-assisted selection to develop onion cultivars with high anthocyanin content.
An allo-octoploid strawberry (Fragaria × ananassa Duch.) is one of the most important vegetable crops in Korea. However, there were few genomic researches of strawberry due to polyploidy and complexity of its genome. In this study, we aimed to construct a genetic linkage map of strawberry using single nucleotide polymorphism (SNP) markers that were developed through a next-generation sequencing (NGS) analysis. Two strawberry varieties, ‘Sulhyang’ and ‘Senga-sengana’, were used as a maternal and a paternal parent, respectively, and their F1 generation consisting of 94 individuals was used for construction of a genetic linkage map. A total of 19.0 Gbp (‘Sulhyang’) and 21.8 Gbp (‘Senga-sengana’) of genomic sequences were obtained through NGS analysis. Subsequently, approximately 87,000 SNPs were identified and 1,154 primer sets for high-resolution melting (HRM) analysis were designed through bioinformatic analysis. In result, a total of 224 polymorphic HRM markers were developed and 205 markers were mapped on the genetic linkage map of strawberry, which total length was 800.8 cM and the number of linkage groups were 30. This SNP-based genetic linkage map and the 224 SNP markers will be very helpful for the genomic and genetic researches of allo-octoploid strawberry.