8个金荞麦种质光合及光响应曲线特性研究

Study on Photosynthesis and Light Response Curve Characteristics of 8 Fagopyrum dibotrys Germplasm

以西南地区的8个野生金荞麦为研究对象,利用Li-6400便携式光合作用测定仪测定其不同光合参数,绘制相应光响应曲线。结果表明,随着光合有效辐射(PAR)的增加,JQM 1的净光合速率先快速上升后下降,产生光抑制现象,其余7个种质先快速上升后趋于平稳。8个金荞麦种质气孔导度(Gs)和蒸腾速率(Tr)随PAR增加呈快速上升后平稳或上升趋势,胞间二氧化碳浓度(Ci)呈迅速下降后平稳趋势,水分利用效率(WUE)呈快速上升后趋于平稳趋势;直角双曲线修正模型更好的拟合光合-光响应曲线,拟合决定系数(R^(2))均大于0.923。8个金荞麦种质光饱和点(LCP)范围为18.46~35.01μmol/(m^(2)·s),光补偿点(LSP)范围为617.39~1 706.70μmol/(m^(2)·s),均属阳性植物;JQM 1的LSP最低,强光利用能力最弱;JQM 2、JQM 6的LCP较低,对弱光利用能力强,其中JQM 1、JQM 2两个种质的净光合速率较高,光合能力强;JQM 4的LCP、LSP相对较高,对强光利用能力强;JQM 5的LCP较低,LSP较高,对光能利用范围最广。

Taking 8 Fagopyrum dibotrys in the southwest region as the research object, Used the Li-6400 portable photosynthesis measuring system to measure different photosynthetic parameters and draw the corresponding light response curve.The result showed that, with the increase of photosynthetically active radiation(PAR), the net photosynthetic rate of JQM 1 showed a rapid rise and then a downward trend, resulting in photoinhibition. The remaining 7 germplasms showed a rapid rise and then stabilized. The stomatal conductance(Gs) and transpiration rate(Tr) of 8 F. dibotrys germplasm showed a rapid increase and then a steady or upward trend with the increase of PAR, the intercellular carbon dioxide concentration(Ci) showed a rapid decline and then a steady trend, and the water use efficiency(WUE) after a rapid rise, it tended to be stable. The right-angle hyperbolic modified model better fits the photosynthesis-light response curve, and the fitting determination coefficient(R^(2)) was greater than 0.923. The light saturation point(LCP) range of the 8 F. dibotrys germplasm was 18.46-35.01 μmol/(m^(2)·s), and the light compensation point(LSP) range was 617.39-1 706.70 μmol/(m^(2)·s), all of which were positive plants. JQM 1 had the lowest LSP and the weakest ability to use strong light. JQM 2 and JQM 6 had lower LCP and strong ability to use weak light. Among them, JQM 1 and JQM 2 had higher net photosynthetic rate and strong photosynthetic capacity. JQM 4 The LCP and LSP of JQM 5 were relatively high, and the ability to use strong light was strong;the LCP of JQM 5 was lower, the LSP was higher, and the range of light energy utilization was the widest.