Identification of wheat dwarf mutants and analysis on association between the mutant traits of the dwarf plants

Abstract

<p indent=0mm>Dwarf mutant is an important gene resource in wheat breeding and plant height genetic research. In this paper, EMS (ethyl methyl sulfonate) was used to mutate the mature seeds of ‘Yunmai 53’, and 33 candidate dwarf mutants of M₃ generation were finally obtained by self-bred. Twenty-six dwarf mutants were selected by analyzing differences between the mutant parent in two years and that of M₂ and M₃ generation candidate plants, and the variation range of their plant height was from (13.61 ± <sc>0.11) cm</sc> to (44.08 ± <sc>1.73) cm.</sc> Twenty-six dwarf mutants with at least 2 mutant sites were verified based on 12 specific markers of 8 dwarf genes. In addition to plant height, 26 dwarf mutants also carried four mutational traits, spike length, spikelet density, internode number, and average internode length. The 26 dwarf mutants could be clustered into 5 subgroups. Among them, the first subgroup was the least in spikelets and florets, the second subgroup was the shortest in plant height, spike length and average internode length, and the highest spikelet density, while the third subgroup was the least in internode number. Plant height was significantly correlated with average internode length and internode number with partial correlation coefficients of 0.94 and 0.58, respectively, but not correlated with spike length, spikelet number and spikelet density. The plant height was genetically associated with internode length and internode number in 26 dwarf mutants. The mutants carried different combinations of the mutant gene, and can be useful in wheat dwarf breeding and the studies on genetic mechanism of the traits, such as plant height, spike length and spikelet density.