渍害下小麦相对叶绿素含量的降低效应及其与产量的相关性

Reduction Effects on SPAD Values of Wheat Leaves and Its Correlation with Yield under Waterlogging Stress

为了探讨渍水对小麦(Triticum aeestivum)叶片的相对叶绿素含量的降低效应及其与产量的相关性,以来源于不同麦区推广品种和高代品系共164份为材料,在抽穗扬花期进行人工模拟渍害处理,以正常水分区为对照,分别测定渍水前和渍水后不同品种(系)倒1叶~倒4叶的SPAD值(相对叶绿素含量),成熟期测定其产量,计算不同品种(系)的SPAD值和产量的渍害指数,然后进行比较分析。结果表明,小麦抽穗扬花期渍水SPAD值显著下降,不同叶位叶片的SPAD值下降程度差异显著。渍水12d对倒1叶SPAD值的影响不显著,对倒2叶~倒4叶的SPAD值的影响均达到极显著水平;对照区渍水处理前后的倒2叶的SPAD值有自然下降的趋势,但差异不显著,倒3叶和倒4叶的SPAD值在处理前后12d间的差异达到极显著水平。渍水时间达到12d以上,考察倒2叶的SPAD值即可判断受害程度,渍水时间小于12d以下,考察倒3叶的SPAD值为佳。倒3叶~倒4叶的SPAD值渍害指数和产量的相关关系相对较大,因而在进行小麦不同品种耐渍性比较试验时,选择测定倒3叶~倒4叶的SPAD值,才能得到较好的不同品种间耐渍性差异。

The reduction effects on SPAD values of wheat(Triticum aeestivum)leaves and its correlation with yield under waterlogging stress were carried out.The field experiment was conducted at flowering stage of wheat.One hundred and sixty four cultivars or advanced lines were used as experiment materials,which were collected from different wheat-planting areas,and an artificial simulation waterlogging treatment was designed with normal water condition as control in the trial.SPAD values were measured respectively before waterlogging treatment and after the treatment in the plots of treatment and control.Yield was measured at maturity stage.The waterlogging indexes both of SPAD values of different leaves and yield were calculated for different wheat cultivars and compared.The results showed that SPAD values of wheat were significantly reduced at flowering stage under waterlogging condition and the SPAD values showed significant difference for leaves in different stem positions.SPAD values of the first inverse leaf showed no significant difference but SPAD values of the second inverse leaf to the inverse fourth leaf were in the opposite way under waterlogging treatment of 12 days.SPAD values showed a natural reduction with no significant difference at the 12 days of waterlogging treatment for the second inverse leaf but with the opposite results for the third and fourth inverse leaves in the control plots.SPAD value of the second inverse leaf could be utilized to measure the injury degree of waterlogging when treatment period was more than 12 days and the third inverse leaf was the optimum when treatment period was less than 12 days.The SPAD value of the third and fourth inverse leaves were the first choice when waterlogging tolerance of different varieties or advanced lines were compared for its higher correlation with yield under waterlogging stress.