开顶式气室内外冬小麦光合特性差异比较研究

Abstract

PDF HTML阅读 XML下载 导出引用 引用提醒 开顶式气室内外冬小麦光合特性差异比较 DOI: 10.5846/stxb201402200299 作者: 作者单位: 江西省气象科学研究所,江西省农业气象试验站,江苏省气象灾害重点试验室,江苏省气象灾害重点试验室,云南省气候中心,气象防灾减灾湖南省重点实验室 作者简介: 通讯作者: 中图分类号: 基金项目: 国家自然科学基金(41075114) Comparative of the photosynthetic characteristics of winter wheat grown inside and outside open-top chambers Author: Affiliation: Eteorological Research Institute of Jiangxi Province,Agro-meteorological Experiment Station of Jiangxi Province,,Jiangsu Key Laboratory of Meteorological Disaster,,Key Lab of Hunan Province for Meteorological Disaster Prevention and Mitigation Fund Project: 摘要 | 图/表 | 访问统计 | 参考文献 | 相似文献 | 引证文献 | 资源附件 | 文章评论 摘要:为探明开顶式气室(OTC)内外冬小麦光合特性的差异,测定了OTC内(T1处理组,冬小麦整个生育期生长在OTC内)和OTC外(T2处理组,大田自然环境组)冬小麦(扬麦16)不同生育期的气体交换参数、光合色素含量和叶绿素荧光参数。结果表明,T1处理的净光合速率Pn、气孔导度Gs、胞间CO2浓度Ci、最大光合速率Pm和半饱和光强Ik大部分生育期均大于T2;灌浆之前T1的表观量子效率AQY较高,蒸腾速率Tr和暗呼吸速率Rd较低,灌浆之后则出现逆转。大部分生育期T1处理叶绿素和类胡萝卜素含量均显著大于T2。T1处理的初始荧光Fo和最大荧光Fm均大于T2,而两者最大光量子产量Fv/Fm大部分生育期无显著差异,孕穗期和扬花期T1处理光化学淬灭系数qP显著低于T2。T1和T2处理PSⅡ的实际光化学量子效率Y(II)大部分生育期无显著差异,但灌浆期以后T1的非光化学淬灭系数NPQ和PSⅡ处调节性能量耗散的量子产量Y(NPQ)显著大于T2,而PSⅡ处非调节性能量耗散的量子产量Y(NO)显著低于T2。由此可见,OTC内冬小麦的气体交换能力和光响应能力均优于OTC外,光合色素含量也更高;OTC内外冬小麦内禀光能转换效率和实际光化学量子效率相当,但OTC内冬小麦过剩光能向调节性热耗散分配的比例较高而向非调节性热耗散分配的比例较低,其光保护能力更强,光能分配也更加合理。 Abstract:The open-top chamber (OTC) is an important device used to study the impact of climate change on ecosystems. These chambers have been widely used in climate change simulation and pollution ecology research. Compared to the conventional closed artificial climate chamber or the newly developed free-air concentration enrichment (FACE) method, the OTC creates a microclimate that is more similar to the atmospheric environment. Moreover, its test gas concentration control is more precise, and its construction and operating costs are lower. Our research results indicated that microclimatic elements inside and outside the OTC are different. Although much research has been carried out on microclimatic elements inside and outside the OTC, and improvements have been made based on these research results, there are only a few reports on the growth and photosynthetic response of plants to these microclimatic differences.This study aimed to evaluate the photosynthetic response of winter wheat (Triticum aestivum L.) grown inside (T1) and outside (T2) an OTC, using the plants of a modern cultivar, 'YangMai16.’ Gas exchange, photosynthetic pigment content, and chlorophyll fluorescence parameters were evaluated. The test field was located at the Agricultural Meteorological Experiment Station of Nanjing University of Information Science and Technology, China (32°03'N, 118°51'E). The seeds were sown on November 5, 2009, by drilling, with a seeding rate of 220.5 kg/hm2, and plants were harvested on May 31, 2010. The daily mean temperature and relative humidity inside the OTC used in our experiments were 8.9% and 3.3% higher, respectively, than those of the atmospheric environment; however, total radiation was 20.4% lower. The differences in microclimatic elements inside and outside the OTC used in this study were similar to those recorded by other groups.Our results indicated that the net photosynthetic rate (Pn), stomatal conductance (Gs), intercellular CO2 concentration (Ci), max photo-synthetic rate (Pm), and half-saturation light intensity (Ik ) of T1 were significantly higher than those of T2 (P<0.05). Before the filling stage, the apparent quantum yield (AQY) of T1 was significantly higher than that of T2, whereas transpiration rate (Tr) and dark respiratory rate (Rd) were significantly lower (P<0.05). After the filling stage, the results reversed. The chlorophyll and carotenoid contents of T1 were significantly higher than those of T2 during most of the growth stages P<0.05). The basic fluorescence yield (Fo) and dark-adapted maximum fluorescence yield (Fm) values of T1 were higher than those of T2, but there was no difference in the maximum photochemical capacity of PSⅡ (photosystem II) (Fv/Fm) between T1 and T2 during most of the growth stages. In the booting and flowering stages, the photochemical quenching coefficient (qP) of T1 was significantly lower than that of T2 (P<0.05). There was no difference in the quantum yield of photochemical energy conversion in PSⅡ [Y(II)]of T1 and T2 during most of the growth stages. The non-photochemical quenching coefficient (NPQ) and quantum yield of regulated non-photochemical energy loss in PSⅡ [Y(NPQ)] of T1 were significantly higher than those of T2 after the filling stage (P<0.05), whereas the quantum yield of non-regulated non-photochemical energy loss in PSⅡ [Y(NO)] was lower. Our results indicate that the gas exchange capability, light response capability, and photosynthetic pigment content of winter wheat grown inside the OTC were higher than those of wheat grown outside. There were no differences in the maximum photochemical capacity and quantum yield of photochemical energy conversion in the PSⅡ of winter wheat grown inside and outside the OTC. In contrast, the fraction of energy dissipated as heat via the regulated photo-protective NPQ mechanism was higher, while the fraction that was passively dissipated in the form of heat and fluorescence was lower, for winter wheat grown inside the OTC. Photo-protection of the photosynthetic apparatus from excess energy in PSⅡ was also better in the winter wheat grown inside the OTC. Our results are expected to help improve OTCs, including the evaluation of data from controversial ecology projects and the application of research knowledge obtained from OTCs to field conditions. 参考文献 相似文献 引证文献