Abstract: 【Objective】A molecular genetic linkage map for cultivated naked oat based on SSR markers was developed and Quantitative Trait Loci influencing β-glucan content were identified, in order to facilitate the utilization of high β-glucan content oat germplasm resources and provide a theoretical basis for oat molecular marker-assisted selection.【Method】 Taken a segregation population of 215 F2:3 lines which originated from the cross with the high β-glucan content local cultivar Xiayoumai was used as the male parent and improved cultivar Chi38 Youmai as the female as mapping population, a molecular genetic linkage map of oats with SSR markers was developed. The β-glucan content of segregation population was determined by the standard β-glucan measure method (AACC Method 32-23) which was published by American Association of Cereal Chemists and the QTLs for β-glucan content of oat were analyzed and identified by Composite Interval Mapping method. 【Result】 After detection of F2 progenies with 231 pairs of SSR primers, a total of 261 polymorphic markers were obtained. The polymorphic markers mentioned above were analyzed for their genetic linkage relationship by JoinMap 4.0 and finally the oat genetic linkage map was constructed. The map included 26 linkage group, 182 SSR markers and covers 1869.7cM of the whole genome. The average space between markers was 10.6 cM. The number of markers in each linkage group varied from 2 to 14 and the length of the linkage group varied from 10.6 to 235.1 cM. The results of the measurement of the parents and segregation population’s β-glucan content showed that β-glucan content in the offspring groups presented as significant separation and continuous variation with variation coefficient of 18.72%, which indicated that β-glucan content traits are controlled by multiple genes of quantitative traits and the segregation population meets the requirements of QTL mapping. The SSR data were analyzed by QTL analysis software WinQTL Cart 2.5 and whole genome were scanned by Composite Interval Mapping method to identify the possible QTLs for β-glucan content and estimate QTL effect with the LOD=5 as a threshold. Four QTLs correlative to β-glucan content were found. qBG-1 was on the twentieth linkage group and explained 10.9% of phenotype variation with the additive genetic effects value is 0.21 and the nearest marker AM591 showed a genetic distance of 10.0 cM to qBG-1. qBG-2 and qBG-3 were on the twenty-third linkage group and explained 3.2% and 2.7% of phenotype variations with the additive genetic effects values of -0.23 and -0.22, respectively, and the nearest marker AM1832 showed a genetic distance of 4.6cM to qBG-2 and 1.9 cM to qBG-3 by AM641, qBG-4 was on the twenty-fifth linkage group and explained 27.6% of phenotype variation with the additive genetic effects value of 0.84 and the nearest marker AM302 showed a genetic distance of 6.8 cM to qBG-4. The two main QTLs, qBG-1 and qBG-4, all originated from the high β-glucan content male parent Xiayoumai. 【Conclusion】A genetic linkage map was constructed，and four QTLs which affect β-glucan content of naked Oat were identified, thus providing a scientific basis for molecular marker-assisted selection in oat breeding.

Key words: naked oat , genetic linkage map , SSR , β-glucan , QTL