Mapping the major quantitative trait loci of the heading date trait in Qingke barley (Hordeum vulgare L.) from the Qinghai-Tibetan Plateau via genotyping by sequencing

Abstract

A key trait impacting the maturity of qingke is the heading date. Identification of major stable quantitative trait loci (QTL) for heading date trait is important for maturity improvement in qingke. Therefore, we conducted QTL mapping of an F₂ population of 146 lines and constructed a high-density linkage map with 1,243 recombination bin markers. After phenotyping the F_2:3 across three environments to detect QTL for heading date. The results showed that three QTLs that play a major role in heading date were identified, cqHD2H-1 and cqHD2H-2 were identified across two environments and considered environmentally stable. The cqHD2H-2, reflects a stable early-heading locus, explaining 27.50% of the phenotypic variance. Mapping of the cqHD2H-2 was subsequently conducted in extremely heading individuals from F₅ populations, the cqHD2H-2 was further delimited to a region of approximately 84 Mb on 2H, and the HORVU2Hr1G087460 gene was identified as a homologue of the rice DTH8 gene by a BLASTN analysis of the candidate region. These results broaden our understanding on genetic basis of heading date and provide clues for fine mapping and marker-assisted qingke maturity breeding with optimized plant architecture for promising loci.

KEYWORDS:

• Qingke
• hulless barley
• heading date
• QTL mapping
• cqHD2H-2
• HORVU2Hr1G087460

Acknowledgements

We thank Handong Wang of the Northwest Institute of Plateau Biology, Chinese Academy of Sciences, for assisting with the data analysis.

Disclosure statement

No potential conflict of interest was reported by the author(s).

Data availability statement

The data that support the findings of this study are openly available in figshare.com at https://doi.org/10.6084/m9.figshare.14866248.v4.

Additional information

Funding

This research was funded by the Natural Science Foundation Project of Qinghai Province [grant number 2021-ZJ-950Q], the Qinghai Key Laboratory of Hulless Barley Genetics and Breeding [grant number 2021-ZJ-Y13] and the Innovation Fund of the Qinghai Academy of Agricultural and Forestry Sciences [grant number 2019-NKY-05].