Abstract: 【Objective】The awn has a significant influence on stress resistance and spikes photosynthetic characteristics in wheat. The objective of this study is to explore the principal-effect QTLs which control the stable expression of awn and their close chain or total separation of molecular markers, and to provide evidences for molecular marker assisted breeding, constructing near-isogenic line, screening candidate gene and cloning novel genes.【Method】Two F₉ RIL (recombinant inbred lines) populations derived from XY81/Z8425B and XY81/XN1376 were used as drawing population, and two linkage maps were constructed by using 90K array which covering 21 chromosomes of wheat, and the two F_9﹕10 families which including 102 and 120 lines, respectively, were used for the identification of field traits. The two F9:10 families were planted in Yangling District (Shaanxi Province), Nanyang City (Henan Province) and Zhumadian City (Henan Province) from October 2016 to June 2017, respectively. The phenotypic data of awn length of two populations were used to detect QTLs by using the complete interval mapping and multi-environment joint analysis at the ripening stage.【Result】Two genetic maps covering 21 chromosomes of wheat were constructed, the total length of map was 4 412.14 and 4 281.67 cM, respectively. And the average genetic distance was 2.65 and 2.31 cM, respectively. The number of linkage markers in the two linkage maps indicated that the 90K marker was unevenly distributed in wheat genomes A, B and D, but was all expressed as the number of markers in genome B＞that in genome A＞that in genome D. The common marker of D genome was the least for the common markers of two linkage maps, and it indirectly reflected that the D genome was highly conserved. Six QTLs were found in two RIL populations from Yangling District (Shaanxi Province), Nanyang City (Henan Province) and Zhumadian City (Henan Province). The major QTL, Qal5A-1, showed a strong stability in two populations under three environments and was belonged to environment-insensitive QTL. The phenotypic variance explained by Qal5A-1 ranged from 46.01% to 79.82%. It showed inhibitory effects on awn length, and the additive effects came from parent Xiaoyan 81. This major QTL was mapped at the end of chromosome 5A and was closely linked to the molecular marker RAC875_c8121_1147. The phenotypic variance explained by 5 QTLs, including Qal6B-1, Qal1B-1, Qal3B-1, Qal2D-1 and Qal2D-2, were 1.39%, 3.66%, 3.93%, 5.53% and 3.51%, respectively, which were micro-effect QTLs. Two QTLs were found in the RIL group derived from XY81/Z8425B, including one major OTL Qal5A-1 and one micro-effect QTL Qal6B-1, the two loci explained the phenotypic variance was 79.91%. Five QTLs were found in the RIL group derived from XY81/XN1376, including one major OTL Qal5A-1 and four micro-effect QTLs Qal1B-1, Qal3B-1, Qal2D-1 and Qal2D-2, the five loci explained the phenotypic variance was 63.96%. Six QTLs were obtained by multi-environment analysis, and the contribution rate of phenotypic variation of their interaction effects was much lower than that of additive effect, which indicated that the interaction between QTL and environment was not the main factor of influencing awn length. The additive effect values were approximately equal in different environments, further indicating that these six QTLs had a stable genetic effect among the three environments. 【Conclusion】The dominant QTL, Qal5A-1, was detected in two groups. It can be stably expressed and closely linked to the molecular marker RAC875_c8121_1147. It explains the phenotypic variance from 46.01% to 79.82%, which has a strong inhibitory effect on awn length.

Key words: Triticum aestivum, awn length, 90K array, QTL, linkage map