小麦生育后期不同叶位光合色素含量比较

Comparison of Photosynthetic Pigment Content in Leaves of Different Positions at Late Growth Stage of Wheat

为了研究小麦生育后期不同叶位的叶片衰老情况,采用分光光度法,以郑麦7698、周麦18、矮抗58、京411小麦品种为材料,对抽穗期、灌浆中期和成熟期小麦不同叶位光合色素含量进行了测定比较。结果表明,抽穗期和灌浆中期,4个小麦品种不同叶位叶绿素a、叶绿素b、总叶绿素和类胡萝卜素含量均表现为旗叶>倒2叶>倒3叶,且品种间差异不大。抽穗期,4个品种旗叶、倒2叶和倒3叶平均叶绿素a含量分别为3.22、2.68、2.34mg/g,叶绿素b含量分别为1.02、0.89、0.82mg/g,类胡萝卜素含量分别为0.59、0.49、0.43mg/g;灌浆中期,旗叶、倒2叶和倒3叶4个品种平均叶绿素a含量分别为3.22、2.68、1.86mg/g,叶绿素b含量分别为1.29、1.15、0.81mg/g,类胡萝卜素分别为0.14、0.08、0.05mg/g。而成熟期不同叶位间光合色素变化无明显规律,且品种间差异较大。叶绿素a/b值在抽穗期和灌浆中期也基本呈现出随着叶位上升而升高的规律,而成熟期叶绿素a/b值明显降低,且倒3叶叶绿素a/b值高于旗叶,相同叶位品种间叶绿素a/b值变化不大。

Photosynthetic pigment contents of four wheat （Triticum aestivum L. ） cultivars, Zhengmai 7698, Zhoumai 18,Aikang 58 and Jing 411 ,were determined by the method of spectro- photometric determination. The results showed that the contents of chlorophyll a, chlorophyll b, total chlorophyll and carotenoid of the four wheat cultivars were top first leaf〉second leaf〉third leaf at heading stage and mid grain filling stage. At heading stage,the average content of chloro- phyll a of the four cultivars in first leaf,second leaf and third leaf was 3.22,2.68 and 2.34 mg/g respectively,the average content of chlorophyll b was 1.02,0.89 and 0.82 mg/g respectively,and the average content of carotenoid was 0.59,0.49 and 0.43 mg/g respectively. At mid grain filling stage,the average contents of chlorophyll a, chlorophyll b and carotenoid in first leaf, second leaf and third leafs of the four cultivars were 3.22,2.68 and 1.86 mg/g;1. 29,1.15 and 0.81 mg/g; 0.14,0. 08 and 0. 05 mg/g, respectively. The photosynthetic pigment contents had no obvious difference among different cultivars. At mature stage,no obvious regular pattern was found in the photosynthetic pigment contents between different leaves, but great difference existed in different cultivars. The variation law of the chlorophyll a/b was similar to photosynthetic pigment content, and it increased with the incre,ase of leaf position at heading stage and mid filling stage. While at mature stage,the chlorophyll a/b decreased obviously and was higher in third leaf than in first leaf,and maintained stable at the same leaf position between different cultivars.