Genetic analysis of wheat dwarf mutant <italic>je0098</italic> and molecular mapping of dwarfing gene

Abstract

<p id="C3">Lodging easily causes severe decrease in wheat yields. Identification and utilization of favorable dwarfing genes is the key to develop new varieties with high yield and lodging resistance. In this study, a dwarf mutant <italic>je0098</italic> as material was induced by EMS mutagenesis from Jing 411 (WT) and had fine characteristics in yield components. We mapped the dwarfing gene through genetic analysis of plant height, and combining with exon capture sequencing and genetic linkage analysis. Statistical analyses of plant height in three-year field experiment suggested that plant height of <italic>je0098</italic> was 15 cm lower than that of WT. Histocytological analysis of <italic>je0098</italic> and WT indicated that the internode cell length of <italic>je0098</italic> was about 18% shorter than that of WT, suggesting that the shorter internode cell length caused the dwarfism of <italic>je0098</italic>. Gibberellic acid treatment showed that <italic>je0098</italic> was a gibberellic acid-sensitive dwarf mutant. An F₂ segregation population consisting of 344 individuals was constructed by crossing WT and <italic>je0098</italic>. Combining with the phenotypic data of F_2:3 families, dwarf homozygous and tall individuals were selected to construct progeny pools. Exon capture sequencing was performed on the two parents and progeny pools, respectively. A quantitative trait locus (QTL) with effects on reduced height was identified on chromosome 2D. Based on SNPs detected by genome-wide sequencing, six KASP markers were developed on chromosome 2D to genotype F₂ individuals. Genetic linkage map was constructed using QTL IciMapping. Combining with phenotype data of three-year field experiment, the dwarfing gene was mapped in the range of 20.77-28.84 Mb with genetic distance of 11.48 cM. These results will lay the foundation for further functional research of <italic>je0098</italic> and its application in wheat breeding.