Characterization of a major quantitative trait locus on the short arm of chromosome 4B for spike number per unit area in common wheat (Triticum aestivum L.).

In this study, we used the F2 population derived from a cross between two wheat accessions displaying significant differences in SNPA to perform quantitative trait locus (QTL) analysis. Through bulked segregant analysis, a major and stable QTL that explained 18.11-82.11% of the phenotypic variation was identified on chromosome 4BS. The QTL interval was validated using F4:5 and F6:7 families and narrowed it to a 24.91-38.36 Mb region of chromosome 4BS according to the 'Chinese Spring' reference genome sequence. In this region, variations in 16 genes caused amino acid changes and three genes were present in only one parent. Among these, we annotated a gene orthologous to TB1 in maize (Zea mays), namely TraesCS4B01G042700, which carried a 44-bp deletion in its promoter in the higher-SNPA parent. An InDel marker based on the insertion/deletion polymorphism was designed and used to diagnose the allelic distribution within a natural population. The frequency of the 44-bp deletion allele associated with higher SNPA was relatively low (13.24%), implying that this favorable allele has not been widely utilized and could be valuable for wheat yield improvement. In summary, we identified a major and stable QTL for SNPA and developed a diagnostic marker for the more-spiked trait, which will be beneficial for molecular-assisted breeding in wheat.
PMID: 32347319 [PubMed - as supplied by publisher]

Source: TAG. Theoretical and Applied Genetics - April 27, 2020 Category: Genetics & Stem Cells Authors: Li J, Wen S, Fan C, Zhang M, Tian S, Kang W, Zhao W, Bi C, Wang Q, Lu S, Guo W, Ni Z, Xie C, Sun Q, You M Tags: Theor Appl Genet Source Type: research