论文部分内容阅读
目的通过外源物质对黄连幼苗进行处理,研究黄连幼苗光合特性及叶绿素荧光特性的变化,寻找提高黄连幼苗在盐胁迫条件下抗性能力的途径。方法测定100 mmol/L的Na Cl模拟盐胁迫条件下,经过不同浓度的外源一氧化碳(CO)供体高铁血红蛋白(hematin,H)处理后,黄连幼苗光合色素量、叶绿素荧光参数及气体交换参数等光合生理指标的变化。结果 Na Cl胁迫下的黄连幼苗的光合生理受到显著抑制,但是经过不同浓度的H处理后,显著提高了叶绿素a(Chl a)、叶绿素b(Chl b)、Chl(a+b)和类胡萝卜素等光合色素的量。盐胁迫下,黄连植株的净光合速率(Pn)、气孔导度(Gs)及叶片蒸腾速率(Tr)均下降,并且随着胁迫时间和胁迫浓度的增加,下降幅度逐渐增大,胞间CO2浓度(Ci)则呈上升趋势。在盐胁迫下,黄连Pn降低的主要影响因素是非气孔因素。在应用H进行处理后,黄连的Pn、Gs及Tr均有不同程度地提高,Ci也有不同程度的降低,并且不同的浓度梯度存在着显著的效果差异。H处理还提高了最大荧光(Fm),最大光化学效率(Fv/Fm),光系统II(PSII)潜在活性(Fv/Fo),PSII有效光化学效率(Fv′/Fm′),PSII实际光化学效率(ΦPSII),光化学淬灭系数(q P),电子传递率(ETR)和光化学速率(PCR)的水平,有效地降低了初始荧光(Fo),非光化学淬灭系数(NPQ)和热耗散速率(HDR)的水平。结论外源CO供体H通过提高黄连幼苗叶片的光合色素量,减少过剩激发能的耗散,提高光合电子传递效率,有效地缓解盐胁迫对黄连叶片PSII的伤害,提高植株的抗盐能力。
Objective To investigate the changes of photosynthetic characteristics and chlorophyll fluorescence characteristics of Coptis chinensis seedlings by exogenous substances and to find ways to improve their resistance to salt stress. Methods The contents of photosynthetic pigments, chlorophyll fluorescence parameters and gas exchange parameters of the seedlings of Coptis chinensis under the NaCl stress of 100 mmol / L NaCl stress were measured after treatment with different concentrations of exogenous CO (carbon monoxide) donor hematin (H) Photosynthetic changes such as physiological indicators. Results The photosynthetic physiology of Coptis chinensis seedlings under NaCl stress was significantly inhibited, but the chlorophyll a (Chl a), chlorophyll b (Chl b), Chl (a + b) and carotenoids significantly increased after treatment with different concentrations of H The amount of photosynthetic pigments and the like. Under salt stress, the net photosynthetic rate (Pn), stomatal conductance (Gs) and leaf transpiration rate (Tr) of Coptis chinensis decreased, and with the increase of stress time and stress concentration, the decline amplitude of intercellular CO2 Concentration (Ci) is on the rise. Under salt stress, the main influencing factor of Pn of Coptis chinensis is non-stomatal factor. After treatment with H, the Pn, Gs and Tr of Coptis chinensis increased to some extent, Ci also decreased to some extent, and there were significant differences in the effect of different concentration gradients. H treatment also increased the maximum fluorescence (Fm), maximum photochemical efficiency (Fv / Fm), PSII potential activity (Fv / Fo), PSII effective photochemical efficiency (Fv ’/ Fm’), PSII actual photochemical efficiency (ΦPSII), photochemical quenching coefficient (q P), electron transfer rate (ETR) and photochemical rate (PCR), effectively reducing the initial fluorescence (Fo), the non-photochemical quenching coefficient (NPQ) Rate (HDR) level. Conclusion Exogenous CO donor H can effectively alleviate PSII damage and improve salt tolerance of Coptis chinensis leaves by increasing the amount of photosynthetic pigments in the leaves of Coptis chinensis Franch., Reducing the dissipation of excess excitation energy and increasing the photosynthetic electron transfer efficiency.