Fine mapping and candidate gene mining of QSc/Sl.cib-7H for spike compactness and length and its pleiotropic effects on yield-related traits in barley (Hordeum vulgare L.).

Key Message: A major locus for spike compactness and length was mapped on chromosome 7H and its pleiotropic effects, candidate genes and transcriptional regulatory network were analyzed. Spike compactness (SC) and length (SL) are important traits of barley (Hordeum vulgare L.) due to their close association with grain yield. In this study, a major SC and SL locus QSc/Sl.cib-7H was primarily identified on chromosome 7H by bulked segregant analysis, and further fine mapped to a recombination cold spot expanding 244.36-388.09 Mb by developing a secondary population using residual heterozygous lines. This region is much more accurate than previously reported spike compactness loci on chromosome 7H. The strong effects of QSc/Sl.cib-7H on SL and SC were validated in two pair of near isogenic lines (NILs) and diverse genetic backgrounds. QSc/Sl.cib-7H exhibited pleiotropic effects on plant height (PH), thousand grain weight and grain length, and did not significantly influence the spikelet number of main spike (SMS) and grain width. Transcriptome analysis based on NILs showed that regulation of SC and SL might be related to the plant circadian rhythm pathway. The candidate genes were mined by analyzing variants and expression patterns of genes in the target region employing multiple genome and transcriptome data. This study takes a further step towards cloning of QSc/Sl.cib-7H, and the data obtained and the developed molecular markers will facilitate its utilization in barley breeding.
Competing Interests: Declarations Conflict of interest All authors declare that they have no conflict of interest. Ethics approval The authors declare that this research has no human and animal participants and that the experiments comply with the current laws of China. Consent to participate Not applicable. Consent for publication Not applicable.
(© 2024. The Author(s), under exclusive licence to Springer-Verlag GmbH Germany, part of Springer Nature.)