To develop the STS (Sequence Tagged Site) marker for discrimination between oat cultivars used the EEG (Euchromatin Enriched Genomic) DNA library in oat. The EEG DNA library was constructed the Mcr A and Mcr BC system in DH5 alpha bacterial cell line. About 3,500 EEG colonies had been constructed by using junk DNA exclusion. About 800 colonies were selected that included insert DNA more than 500 bp. It was analyzed the genetic information by using blast searches of NCBI web site. More than three hundred STS primer sets were developed using sequencing data of selected colonies and about 90 primer sets which showed single band were selected in Olgwiri. It was applied to twelve oat cultivars including Olgwiri and has been shown polymorphism at 15%. PCR product which amplified with selected STS primer was treated with six endonucleases and was showed polymorphic bands. These primers could be useful for specific allele tagging in mapping populations and germplasm and for the study of functional genomics of oat.

Sequence-tagged site (STS) markers tightly linked to the bacterial leaf blight (BLB) resistance genes, xa5, xa13 and Xa21, were used in this study. A survey was conducted to find polymorphisms between the resistant and susceptible germplasm in rice. 500 of Korean varieties and 100 of landraces were evaluated in this study. STS marker, RG207 was used to having xa5 resistance gene of rice germplasm. 27 varieties of Korean germplasm showed resistant for xa5 gene. The RG136 an xa-13 marker resulted in a single band of approximately 1kb in all the rice accessions studied. In order to detect polymorphism, digestion of the polymerase chain reaction (PCR) product was performed using a restriction enzyme Hinf Ⅰ. The resistant lines resulted in two bands 0.5kb on digestion with Hinf Ⅰ, while the same enzyme did not digest the PCR product of susceptible lines. No polymorphism was detected in Korean varieties and landraces, indicating that they probably do not contain xa13 gene. pTA248 an Xa-21 marker detected a band of 1kb in the resistant lines and bands of either 750bp or 700bp in the susceptible lines. Among germplasm tested, there are no varieties and landraces with Xa21 resistant gene. The results of the germplasm survey will be useful for the selection of parents in breeding programs aimed at transferring these bacterial blight resistance genes from one varietal background to another.

Co-segregation of male fertility with DNA markers selected by RAPD analysis as being potentially linked to the restorer gene (Rf) for Cytoplasmic male sterility (CMS) was analyzed using segregating F2 population. One RAPD marker directly linked to the Rf locus was identified. Amplification of OPT-02/570 using the STS primers generated a monomorphic band of each fertile plants randomly selected F2 progenies. From these results, this specific marker would be strongly linked to be restoring gene. The use of STS marker is effective in overcoming the reliability of the RAPD phenotype and improving their utility for MAS, co-dominant STS markers are especially very useful.