Fresh market tomato cultivars are divided largely based on fruit color appearance (red or pink), which is attributed by the trait of peel. It had been reported that mutation of the Slmyb12 gene suppresses synthesis of yellow-colored flavonoid (naringenin chalcone) in peel and causes pinkish tomato fruit. Whereas wild-type tomato plants synthesizing naringenin chalcone produce yellow-colored peel, which resulting in the fruit appearance to be red. The present study was performed to investigate the association between the Slmyb12 and fruit color of domestic tomato inbreed lines. A SCAR marker was developed from an Indel mutation site (72bp insertion in exon3) of the Slmyb12, and tested on 22 and 18 red and pink-fruited inbred lines, respectively. Unexpectedly, the results showed that all inbred lines tested had wild-type Slmyb12. The full length sequences of the Slmyb12 were cloned from two inbred lines (FCR1 and FCP1), but the sequence alignment did not identify any nucleotide variations within this gene. Furthermore, scanning of SNPs between FCR1 and FCP1 using SolCAP Tomato SNP array) found no SNPs for Slmyb12. To delimit the genomic region of the gene conferring fruit color of domestic tomato lines, we are analyzing SNPs in the genes adjacent to the Slmyb12 using an F2 population derived from FCR1 x FCP1. So far, one SNP located at 1,750kbp downstream from the stop codon of Slmyb12 was mapped using 54 F2 plants and 83% of phenotype-marker association was revealed, demonstrating that the fruit color is controlled bySlmyb12 indeed, or other neighboring gene(s) involved in the pathway of naringenin chalcone synthesis. Further study with more SNPs will clear up this question.

Most of the melon(Cucumis melo L.) breeding lines in Korea show andromonoecious (male-perfect flowers) sex expression, which requires laborious hand emasculation to produce the F1 seeds. There is a high demand for developing monoecious (male-female flowers) elite germplasm. The present study was carried out to develop molecular markers for selecting monoecious plants based on the CmACS-7 gene [a locus with 1-aminocyclopropane-1-carboxylic acid synthase(ACS) activity] responsible for ethylene synthesis and sex determination in melon. The full length sequences of the CmACS-7 were cloned from a monoecious inbred ‘Mo23’ and an andromonoecious inbred ‘Am24’. Sequence alignment revealed a major SNP(C170T) in exon1 and 18bp indel in intron4 of the CmACS-7, and a CAPS (SNP-C170T) and SCAR (ID4-18) were developed from the SNP and indel, respectively. A total of 453 F2 plants derived from ‘Mo23’ x ‘Am24’ were determined for their sex expression and genotyped using the SCAR marker. A Mendelian ratio of 3(monoecy): 1(andromonoecy) was observed from the F2 population, and sex type of 449 plants (except for four plants that showed incomplete monoecy) cosegregated with the SCAR marker, demonstrating that CmACS-7 is a single dominant gene conferring monoecy of ‘Mo23’. Allele variation of the CmACS-7 was evaluated by genotyping 114 melon accessions with diverse geographical origins using the CAPS and SCAR. C170T-SNP in exon1 of the CmACS-7 was highly conserved in melon germplasm and perfectly matched with the phenotype, whereas the 18bp-indel mutation in intron4 existed in various forms. The results demonstrated that CAPS marker SNP-C170T can be useful for marker-assisted selection(MAS) of monoecious melon plants