Construction And Characterization Of EMS Mutant Library Of Jingu21

Foxtail millet (Setaria italica L.) is one of the important grain crops in Northern China. Awarded the millet Champion five times in the National Agriculture Product Exhibition, Jingu21has been recognized as one of the few best quality millet varieties for over20years and dominates the millet production in Shanxi. Millet quality breeding, however, lags behind, the resources for high quality breeding are scarce and there is no major breakthrough on quality breeding. The problem of time-consuming weeding and thinning during millet cultivation has restricted the mass production of foxtail millet. EMS (ethyl methylsulfonate) chemical mutagenesis method, being of low cost, simple operation and high mutation rate, is one of the important methods for crop breeding. Through EMS mutagenesis of jingu21, a mutant library could be constructed, which would promote the exploration of the excellent quality genetic resources, accelerating millet quality breeding process and laying a foundation for the study of gene function. Millet genome sequencing was completed and published in2012, which provides a rare opportunity for functional genomics of the crop.In this study, we applied0.8%and1.0%EMS to mutagenize Jingu21to construct millet mutant library. The phenotypes of the M3generation in the field were investigated to establish the features of the library. Anti-sethoxydim herbicides mutants were screened and target gene was sequenced to identify the mutation sites. The results were as follows:1. Millet mutant library was obtained in October2012, containing13,914copies of millet. In the library, there were8620lines from0.8%EMS treatment and5294from1.0%EMS.2. There were445mutants showed clear phenotypes in2013, including31leaf color mutants,21(half) dwarf mutants,36earlier flowering mutants,12late flowering mutants,121tillering mutants,3sterile mutants,17upright panicle mutants,4mutants with thicker stem/higher plants/late flowering,2mutants with smaller leaf angle,173panicle mutants and25other mutants.3. After spraying sethoxydim herbicide twice, we obtained nine lines resisting sethoxydim herbicide.