This study was conducted for SNPs in the 5'-regions of estrogen receptor-α(ESR-α), and association with calving interval (CI), service per conception (SPC) and 305 days milk yield in Hanwoo and Holstein dairy cattle. The genet-ic improvement was incurred low reproduction performance. The objective of this study was to investigate connec-tions between single nucleotide polymorphisms (SNP) of Estrogen receptor-α (ESR-α) with reproduction performance (calving interval, service per conception, and 305 d milk yield) in Hanwoo and Holstein dairy cattle. Hanwoo and Holstein blood samples were collected from 183 and 124 dam of breeding farms and DNA was extracted. Primer design was based on NCBI GenBank (Accession No. AY340579). The PCR-RFLP method with Bgl I was used to ge-notype the cattle. The result showed two variants of the ESR-α gene. The Bgl I cut the 492 bp amplification pro- duct into 322 bp and 170 bp fragments for allele G, while allele A remained uncut, resulting in two restriction frag-ments for homozygote G/G and three fragments for heterozygote A/G. We found two of different genotypes in the-se breeds, A/G and G/G. In Hanwoo, the A/G genotype frequency was 0.13, and G/G was 0.87. The CI of A/G was 382.18±10.03 days, and G/G was 381.69±5.22 days. The SPC of A/G was 1.62±0.16, and G/G was 1.32±0.04. While CI showed no significance difference, SPC exhibited significant difference (p<0.05). In Holstein cattle, the frequency of genotype A/G was 0.02 and G/G was 0.98. The 305 days milk yield of A/G was 7,253.00±936.00 kg and of G/G was 8,747.51±204.88 kg, showing no significant difference.

Tomato spotted wilt virus (TSWV) causes one of the most destructive viral diseases that threaten tomato (Solanum lycopersicum) worldwide. So far, eight TSWV resistance genes, Sw1a, Sw1b, sw2, sw3, sw4, Sw-5b, Sw-6, and Sw-7 have been identified and Sw-5b has been incorporated into tomato for prevention of TSWV. The objectives of this research are first to discover single nucleotide polymorphisms (SNPs) in Sw-5 alleles and then to develop SNP markers to distinguish resistant genotypes against TSWV for marker-assisted breeding in tomato. First, DNA sequences of Sw-5b alleles from both resistant and susceptible cultivars amplified using known Sw-5 gene-based marker was analyzed. The single functional SNP (G→A) was detected as non-synonymous substitution because this SNP causes change of arginine (Arg599) to glutamine (Gln599). Next, the primer pair for high resolution melting analysis (HRM) was designed around this SNP. To determine accuracy of this SNP marker to distinguish resistant Sw-5b genotypes against TSWV, genotypes of 32 commercial tomato cultivars were checked. The newly developed SNP marker could select six cultivars carrying resistant Sw-5b genotype, which was 100% correlated with genotypes based on the gene-based marker. These results indicate that the SNP maker developed in this study could be useful for better tracking resistance to TSWV in tomato breeding.