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以毛竹(phyllostachys edulis)为试材,运用开顶式气室(OTCs)模拟了4个大气O3浓度情景,分别为CF(背景大气经活性炭过滤后的处理,22～25nL·L-1)、NF(直接将背景大气输入气室内,40～45nL·L-1)、T1(O3平均浓度100nL·L-1,92～106nL·L-1)、T2(O3平均浓度150nL·L-1,142～160nL·L-1),分析大气O3浓度对毛竹叶片光合色素、气体交换参数、光合参数的影响。结果表明:不同浓度O3处理的毛竹叶片Pn和Tr日变化均呈单峰型,随着O3浓度的升高,叶片Gs、Ci、Ls日变化规律趋于简单,WUE变化趋于平缓。与环境背景大气比较,高浓度O3(≥100nL·L-1)条件下叶片Pn、Ls、WUE日均值和Chl、Chl-a、Chl-b和Car含量均显著降低,Gs、Tr日均值显著提高,但对Ci日均值及叶片光合色素组成影响并不明显。T1、T2处理下,毛竹的Pn、Tr与PPED、VpdL、Tair、Ca和RH环境因子间均呈显著或极显著相关,Gs与PPED无显著相关,而与VpdL、Tair、Ca和RH环境因子间均呈显著或极显著相关。研究表明:O3浓度100、150nL·L-1时分别会造成毛竹叶片发生气孔、非气孔限制,气孔对环境条件的反应变得不敏感,影响了正常的调节反馈机制,增加了水分蒸散,光合色素降解或合成受阻,对毛竹光合作用产生严重的负面效应,不利于毛竹干物质积累。
Phyllostachys edulis (Phyllostachys edulis) was used as experimental material to simulate four atmospheric O3 concentrations using open-top gas chambers (OTCs), which were CF (22-25 nL·L-1) NF (the average background concentration of oxygen was 40 ~ 45nL·L-1), T1 (the average concentration of O3 was 100nL·L-1,92-106nL·L-1), T2 (the average concentration of O3 was 150nL·L-1,142 ~ 160nL·L-1). The effects of atmospheric O3 concentration on photosynthetic pigments, gas exchange parameters and photosynthetic parameters of Phyllostachys pubescens leaves were analyzed. The results showed that the diurnal variation of Pn and Tr in leaves of Phyllostachys pubescens treated with different concentrations of O3 showed a single peak. With the increase of O3 concentration, the daily variation of Gs, Ci and Ls tended to be simple and the change of WUE tended to be gentle. Compared with the atmospheric background, the daily average of Pn, Ls, WUE and the contents of Chl, Chl-a, Chl-b and Car in leaves were significantly decreased under high concentration of O3 (≥100nL·L-1) But it did not affect the daily average of Ci and the photosynthetic pigment composition of leaves. Under the treatment of T1 and T2, the Pn and Tr of Phyllostachys pubescens were significantly or very significantly correlated with the PPED, VpdL, Tair, Ca and RH environmental factors, while Gs and PPED had no significant correlation with the environmental factors VpdL, Tair, Ca and RH Between the significant or very significant correlation. The results showed that stomatal and non-stomatal limitation were induced in leaves of Phyllostachys pubescens when O3 concentration was 100 and 150nL·L-1, respectively. The stomatal responses to environmental conditions became insensitive, which affected the normal regulation feedback mechanism and increased the evapotranspiration, photosynthesis Pigment degradation or blocked synthesis, the photosynthesis of bamboo have a serious negative effect, is not conducive to the accumulation of dry matter in bamboo.