FACE条件下大气O3浓度增高对小麦剑叶光合色素含量的影响

应用FACE研究平台，采用烟农19、扬麦16、嘉兴002、扬麦15和扬辐麦2号等5个小麦品种，以O₃自然浓度为对照，研究了大气O₃浓度增高50%对不同小麦品种剑叶光合色素含量的影响.结果表明：开放式大气O₃浓度增高条件下，小麦剑叶叶绿素a (Chl a)、叶绿素b (Chl b)、叶绿素总量Chl(a+b)和类胡萝卜素含量在孕穗期和开花期与对照差异不显著，而花后各时期均不同程度的降低，其中，Chl a、Chl b和Chl(a+b)含量下降达显著水平，说明大气O₃浓度增高对叶绿素合成影响较小，但加速了其衰降过程.不同品种小麦剑叶光合色素含量对大气O₃浓度增高的反应存在基因型差异，扬麦15和嘉兴002对大气O₃浓度增高的敏感性弱于扬麦16、扬辐麦2号和烟农19.在籽粒灌浆盛期(花后21 d左右)，剑叶Chl a、Chl b和Chl(a+b)含量与千粒重呈显著正相关.

Effects of elevated atmospheric ozone concentration on flag leaf photosynthetic pigment contents of wheat.

By using a free air controlled enrichment (FACE) system, this paper studied the effects of elevated atmospheric ozone (O3) concentration (150% of ambient O3) on the flag leaf photosynthetic pigment contents of wheat varieties Yannong 19, Yangmai 16, Jiaxin 002, Yangmai 15, and Yangfumai 2. For the test varieties, no significant differences were observed in the flag leaf chlorophyll a, chlorophyll b, chlorophyll (a+b), and carotenoid contents between treatments elevated O3 concentration and ambient O3 at booting and anthesis stages, but the photosynthetic pigment contents in treatment elevated O3 concentration all decreased after anthesis, with a significant decrease of chlorophyll a, chlorophyll b, and chlorophyll (a+b) contents, which indicated that elevated O3 had minor effects on the synthesis of photosynthetic pigments but accelerated their decline process. Different wheat varieties had genetic difference in the responses of flag leaf photosynthetic pigment contents to elevated O3, among which, Yangmai 15 and Jiaxin 002 had better tolerance to ozone stress. The flag leaf chlorophyll a, chlorophyll b, and chlorophyll (a+b) contents at grain-filling stage (about 21 days after anthesis) had a significant positive correlation with the 1000 grain mass.