Abstract:

The objective of this study was to identify novel major QTLs conferring plant height with breeding potential, and to screen favorable gene loci for marker-assisted selection, so as to provide theoretical basis and molecular resources for plant architecture improvement, lodging resistance improvement and high-yield breeding in wheat. A total of 162 doubled haploid (DH) lines derived from wheat cultivars AN1589 and LX6 were used as experimental materials, which exhibited significant phenotypic variation in plant height. The DH population was genotyped with the wheat 55K SNP array, and polymorphic molecular markers were screened to construct a high-density genetic linkage map. Combined with phenotypic data of plant height collected from six environments across three consecutive years, genome-wide QTL mapping was performed for plant height traits. Four environmentally stable major QTLs were detected via inclusive composite interval mapping (ICIM), which were distributed on chromosomes 4B, 4D, 5D and 6D, individually explaining 7.08%-39.31% of the phenotypic variation. Among them, Qph.ahau-4B was steadily identified in all six environments and BLUP analysis, explaining 28.65%-39.31% of the phenotypic variation. This locus covered a physical interval of 20.61-22.26 Mb, flanked by markers AX-109018264 and AX-109968140, with an additive effect ranging from -9.34 cm to -8.68 cm. This QTL presented prominent genetic effect and high environmental stability, and was verified as a novel and previously unreported major dwarfing QTL by literature comparison. In conclusion, a novel major and environmentally stable QTL for plant height was successfully identified on chromosome 4B. It lays a foundation for subsequent fine mapping, gene cloning and molecular marker-assisted breeding in wheat.

Key words: Wheat, Plant height, 55K chip, QTL

CLC Number: 

• S512.1小麦

• Q78基因工程(遗传工程)