| 摘要: |
| 【目的】研究不同连作年限下兰州百合（Lilium davidii var.unicolor salisb）光合参数日变化及其与生理生态因子的关系，筛选出影响兰州百合光合作用的主要生理生态因子。【方法】采用Li-6400便携式光合作用系统分别测定正茬、连作2年和连作4年兰州百合叶片光合特性及生理生态因子的日变化进程；通过相关分析、通径分析及多元逐步回归分析探讨净光合速率（Pn）和生理生态因子的关系。【结果】07:00-17:30，光合有效辐射（PAR）和空气温度（Ta）均呈单峰曲线，先升高后降低，13:45达到峰值；空气相对湿度（RH）呈“V”形变化，大气CO2浓度（Ca）变化较小。正茬、连作2年和连作4年兰州百合Pn均呈双峰曲线，具有明显的“光合午休”现象；气孔导度（Gs）总体呈下降趋势，胞间CO2浓度（Ci）呈“W”形变化，气孔限制值（Ls）变化趋势与Ci相反；蒸腾速率（Tr）呈倒“V”形变化，水分利用效率（WUE）呈“M”形变化趋势。随连作年限的延长，兰州百合Pn、Gs、Tr及WUE的日均值呈不断下降趋势，而Ci日均值逐渐上升，与正茬相比，连作4年兰州百合各指标变化差异均达显著水平（P<0.05），非气孔因素是引起连作兰州百合Pn下降的主要原因；相关分析、通径分析及多元逐步回归分析表明，PAR、Tr和WUE是影响兰州百合Pn的主要生理生态因子。【结论】随着连作年限的延长，兰州百合光合作用能力不断下降；各生理生态因子对兰州百合不同的光合参数影响程度不尽相同，其中PAR、Tr和WUE的影响程度较大。 |
| 关键词: 兰州百合 连作年限 光合特性 生理生态因子 |
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| 基金项目:国家自然科学基金项目（31560380）；甘肃省高等学校创新能力提升项目（2019A-072）；甘肃农业大学校级自列项目（GSAU-ZL2015-007） |
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| Relationship between diurnal variations of photosynthetic characteristics and physiological and ecological factors of Lilium davidii var. unicolor salisb in different continuous cropping years |
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HUANG Yufang,ZHANG Enhe,ZHANG Xinhui,et al
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| Abstract: |
| 【Objective】The relationships between diurnal variations of photosynthetic parameters of Lilium davidii var.unicolor salisb in different continuous cropping years with various physiological and ecological factors were investigated to choose main factors affecting its photosynthetic rate.【Method】The diurnal changes of photosynthetic characteristics as well as physiological and ecological factors in leaves of L. davidii var. unicolor salisb were measured by Li-6400 portable photosynthetic system.The relationships between net photosynthetic rate (Pn) and physiological and ecological factors were investigated by correlation, path and multiple stepwise regression analysis.【Result】From 07:00 to 17:30,the photosynthetic effective radiation (PAR) and air temperature (Ta) of L. davidii var. unicolor salisb increased first and then decreased, with peaks at 13:45.Air relative humidity (RH) changed in a “V” shape,while atmospheric CO2 concentration (Ca) changed slightly.The Pn of L. davidii var. unicolor salisb under normal cropping,continuous cropping for 2 years and continuous cropping for 4 years all showed two peak curves with obvious midday depression phenomenon.Stomatal conductance (Gs) was generally decreasing.The intercellular CO2 concentration (Ci) showed “W” shape variations,while stomatal limit value (Ls) showed an opposite trend to Ci.Transpiration rate (Tr) showed an inverted “V” shape,and water use efficiency (WUE) showed “M” shape variation.With the extension of continuous cropping time,the daily mean values of Pn,Gs,Tr and WUE presented decreasing trends,while daily mean values of Ci increased gradually.Compared with the first crop,the differences in all indicators in 4 years continuous cropping were significant (P<0.05),suggesting the non stomatal factors were the main cause of Pn decrease.The results of correlation analysis,path analysis and multiple stepwise regression analysis showed that PAR,Tr and WUE were the main physiological and ecological factors influencing Pn of L. davidii var. unicolor salisb.【Conclusion】The photosynthetic capacity of L. davidii var. unicolor salisb decreased with the extension of continuous cropping years.Different physiological and ecological factors had different effects on different photosynthetic parameters of L. davidii var. unicolor salisb,among which PAR,Tr and WUE had the greater effects. |
| Key words: Lilium davidii var. unicolor salisb continuous cropping years photosynthesis characteristics physiological and ecological factors |
