玉米自交系苗期氮敏感基因型差异分析

利用SPAD-502型叶绿素仪进行大量、快速、无损伤测定玉米苗期叶绿素含量提供了线性相关方程，建立了玉米苗期叶片SPAD值与叶绿素含量之间的一元线性回归方程为y=0.077 6x+0.175 6(r=0.92)，呈极显著线性正相关。在低氮与正常供氮条件下，对192份玉米自交系分别进行了苗期(3叶期、6叶期、大喇叭口期)叶绿素含量测定。方差分析显著性检验结果表明，低氮与正常供氮条件下，苗期叶绿素含量均存在极显著的基因型与环境差异，大喇叭口期对氮肥最敏感。192份玉米自交系氮敏感指数变幅为7.55%～39.87%，为玉米育种提供了苗期氮敏感基因型差异数据。

Differences Analysis of Nitrogen Sensitive Genotypes in Seedling Among Maize Inbred Lines

A linear correlation model between chlorophyll content and SPAD value was set up. It might allow us to determine the chlorophyll content without hurt to plants among a large scale of samples. The genotypic difference data on nitrogen responsiveness among 192 elite inbred lines were also reported as the reference data on nitrogen use efficiency breeding in maize. The significant linear function of maize inbred lines between SPAD value and chlorophyll content in seedling stage was y=0.077 6x+0.175 6(r=0.92). The chlorophyll content of 192 maize inbred lines in seedling stage (3 leaves, 6 leaves and large bell stage) were determined in low-nitrogen(LN) and normal-nitrogen(NN) conditions, respectively. The variance analysis indicated that the genotypic and environmental variances were both very significant and the large bell stage was the most sensitive stage under either LN or NN condition. Nitrogen-sensitive index was defined as the percentage of the substations of the chlorophyll content in NN and LN. The nitrogen-sensitive indices of 192 maize inbred lines were analyzed, varied from 7.55% to 39.87%.