广西主要玉米自交系氮利用效率评价

【目的】对低氮胁迫和正常施氮条件下玉米植株的生理指标、产量性状与耐低氮的关系进行研究，为玉米自交系氮利用效率进行有效评价提供参考。【方法】以96份广西主要玉米自交系为材料，通过两年一点两个水平的田间试验，鉴定玉米自交系在低氮和正常氮水平下的产量、吐丝期穗位叶SPAD值、低氮农学利用效率（LNAE）、株高、穗粒数、百粒重和ASI值等性状指标，分析它们之间的相关关系，计算遗传力等，对玉米自交系氮利用效率进行有效评价。【结果】在低氮和正常施氮条件下，各性状遗传变异较大；铁7922、9046、金黄55、P1201-1-1-6、89-1、D黄212、Su137-3 P798-1-3-1-3、M017和越F1-1等玉米自交系氮利用效率较高，应充分利用。低氮条件下，各遗传力较高，正常氮下则较低；穗粒数与产量相关性最高，达0.76。【结论】低氮条件下选育自交系的效率更高；低氮农学效率（LNAE）可作为玉米自交系氮利用效率评价指标；选择与产量相关性较高的性状，能提高选择材料效率。

Evaluation on nitrogen use efficiency in main maize inbred lines of Guangxi

Objective]Relationship among physiological index,yield trait,and low nitrogen tolerance of maize was studied to provide references for effective evaluation of nitrogen use in maize inbred lines.Method]A total of 96 maize inbred lines grown in fields were used to identify correlation among yield.The SPAD value of ear leaf at silking stage,low nitrogen agronomic efficiency(LNAE),plant height,kernel number,100-grain weight,and ASI value under normal and low nitrogen level were all measured and recorded over two consecutive years.Moreover,heritability was calculated and nitrogen use efficiency in maize inbred lines was evaluated.Result]Under low and normal nitrogen level,hereditary variation of all traits varied vastly.Because of their higher nitrogen use efficiency,maize inbred lines Tie 7922,9046,Jinhuang 55,P1201-1-1-6,89-1,D Huang212,Su137-3,P798-1-3-1-3,M017 and Yue F1-1 should be bred effectively.Heritability of all traits investigated under low nitrogen level was higher than that in normal nitrogen level.The correlation coefficients between yield and kernel number was the highest(0.76).Conclusion]Maize inbred lines with low nitrogen level had higher nitrogen use efficiency.LNAE could be used as an indicator in the evaluation of nitrogen use efficiency of maize inbred lines.Selecting maize traits with high yield correlation could improve the selection efficiency of breeding materials.