Modulation of Growth Duration, Grain Yield and Nitrogen Recovery Efficiency by EMS Mutagenesis under OsNRT2.3b Overexpression Background in Rice

Abstract

Growth duration is an important agronomic trait that determines the season and area of crop growth. Previous experiments showed that overexpression of nitrate transporter OsNRT2.3b significantly increased rice yield, nitrogen use efficiency, and growth duration. Through screening, we obtained four ethyl methanesulfonate (EMS)-mutagenized mutants with shorter growth duration compared with O8 of OsNRT2.3b overexpression line. The nitrogen translocation efficiency and physiological nitrogen use efficiency of the mutants were not significantly different from O8, which were increased by 24.4% and 14.2%, respectively compared with WT, but the growth duration of the mutant was significantly lower than O8. Analysis of O8 and mutants showed that the growth duration positively correlated with grain weight per panicle, grain yield, and nitrogen recovery efficiency. In conclusion, our results provide a new idea for balancing rice yield and growth duration.