Construction of linkage map and heading date related QTL analysis using the F_2 population between Japonica rices

摘要

Most of the molecular linkage maps in rice were constructed using segregating populations derived from crosses between parents with a wide genetic distance, such as japonica and indica rices, because of the high polymorphic profiles in them. However, the molecular markers in genetic maps in the populations of japonica/japonica or indica/indica are more useful in practice since these markers can be utilized directly in the concurrent breeding programs. This study aims to develop a genetic map usinga population derived from early heading japonica cultivar Olbyeol and late heading cultivar Ilpumbyeo. Plant height and heading dates were checked in 300 F_2 plants, from which randomly selected sixty plants were analyzed with DNA markers. One hundred and twenty nine polymorphic markers were detected in the segregating population and fifty markers were located in seven linkage groups. Total genetic distance of the seven linkage group was 795.5 cM with an average 17 cM distance between markers. Two QTL for heading days were detected in the linkage group 4 whose individual LOD values were 4.06 and 6.69, respectively. Genetic synteny of the seven linkage groups in the present study is being surveyed with the established rice linkage maps with more molecular markers.