Detection of the introgression loci in Triticum aestivum transferred from Aegilops tauschii by simple sequence repeat (SSR) markers

Abstract

Aegilops tauschii possesses many valuable traits or genes. The introgression loci transferred from A. tauschii in populations of 64 lines of BC₁F₂ and 147 advanced lines of BC₁F₂-F₇ derived from the cross of Chinese Spring (CS; Triticum aestivum) /SQ-214 (A. tauschii) //SW3243 (T. aestivum) was characterized using simple sequence repeat (SSR) markers. 68 polymorphic loci covering the D genome were used to analyze the distribution of A. tauschii SQ-214 introgression loci in the two derived populations. The result shows that 82.35% loci of A. tauschii SQ-214 were detected in BC₁F₂ population, while the frequency of introgression loci was 51.47% in the advanced lines of BC₁F₂-F₇ after artificial selection for stripe rust resistance and agronomic traits. Significant changes of the distribution frequency for the same introgression loci between BC₁F₂ and BC₁F₂-F₇ populations were observed, and seven selective advantage loci from A. tauschii (Xgdm128-3D, Xgdm8-3D, Xgdm72-3D, Xgwm341-3D, Xgdm63-5D, Xgdm132-6D and Xgdm36-6D) were found, which introgression loci distribution frequency increased from 29.69 to 53.91% (BC₁F₂) to 94.22 to 100% (BC₁F₂-F₇). The selective advantage loci could be used to evaluate the desirable genes or traits derived from A. tauschii SQ-214.

Key words: Aegilops tauschii, Triticum aestivum, introgression locus.