Application of Herbicide-Resistant Genes from Green Foxtail Millet in Foxtail Millet Breeding

Foxtail millet (Setaria italica) is nutritious and tolerant to drought and barren conditions, which is an important crop in northern China where there is severe water shortage. However, foxtail millet is very sensitive to herbicide, while its 1000-grain weight is only about 3.0g which makes precision seeding difficult. Thus traditionally seedling thinning and weed control by hand have limited the scale of millet planting. The millet planting area in China has shrunk by 70% in the past 30 years to the current about 1.05 million hm².

Millet materials with resistance to Sethoxydim, Imazethapyr and Nicosulfuron which controlled by a single dominant gene, respectively, have obtained by crossing Chinese cultivated millet varieties with green foxtail (Setaria viridis) herbicide-resistant mutants coming from Canada since 1993. The above materials have been applied in the following four areas: firstly applied for field seedling thinning and weed control by mixing herbicide-resistant and -susceptible sister lines at certain proportion. Secondly by crossing herbicide-susceptible male-sterile line with herbicide-resistant restoring line, the self-crossed sterile line could be killed when herbicide applying.  Thirdly true and false hybrids could be identified when using herbicide-resistant material as male parent crossing with susceptible materials. Fourthly the application of herbicide resistant varieties and hybrids has overcome the obstacle of seedling thinning and weed control by hand in field, which realized large-scale millet production for the first time in China.