盐胁迫下马瑟兰/101-14嫁接苗和自根苗光合生理及叶绿素荧光参数的差异
Analysis on Photosynthetic Physiological and Chlorophyll Fluorescence Parameters between Marselen/101-14 and Own-rooted Marselen Grapes under Different Salt Stresses

采用盆栽方法，研究质量浓度为4 g·L-1 和8 g·L-1 NaCl胁迫下马瑟兰/101-14嫁接苗和自根苗叶片叶绿素质量分数、光合速率(Pn)、荧光参数的差异。结果表明：随着盐质量浓度的增加，马瑟兰嫁接苗与自根苗Pn均逐渐降低，在4 g·L-1 NaCl胁迫下两者的Pn显著差异，而质量浓度为8 g·L-1 NaCl胁迫下嫁接苗的Pn显著大于自根苗。4 g·L-1 盐胁迫下嫁接苗和自根苗的Pn均随着胞间CO2摩尔分数（Ci）下降而降低，说明气孔限制是导致Pn降低的主要原因；8 g·L-1 盐胁迫下嫁接苗和自根苗的Ci升高，而Pn下降，表明非气孔限制是导致Pn降低的主要因素。随着盐质量浓度的增加，马瑟兰嫁接苗和自根苗叶片初始荧光（Fo）逐渐升高， PSⅡ 实际光化学效率Y(Ⅱ)、光化学淬灭系数（qP）和线色素转化效率（Fv′/Fm′）逐渐降低，说明盐胁迫使 PS Ⅱ 的反应中心受到破坏，PSⅡ电子传递受抑制；但马瑟兰嫁接苗荧光参数的变化幅度小于自根苗，说明嫁接苗PSⅡ的反应中心伤害程度小于自根苗，这可能是盐胁迫下嫁接苗Pn高于自根苗的原因。
In a pot culture experiment，Marselen/101-14 and own-rooted Marselen grapes were used as materials, and treated with 4 g·L-1 and 8 g·L-1 NaCl for 35 days, chlorophyll mass fraction, net photosynthetic rate and chlorophyll fluorescence parameters in leaves were measured. Experiment results showed that photosynthetic rate(Pn) gradually decreased in leaves of both Marselen/101-14 and own-rooted Marselen grapes with the increasing of mass concentration of NaCl, the Pn between Marselen/101-14 and own-rooted Marselen leaves had no significantly different under 4 g·L-1 NaCl stresses, while the Pn of Marselen/101-14 was significantly higher than own-rooted Marselen leaves under 8 g·L-1 NaCl stresses. The Pn of both Marselen/101-14 and own-rooted Marselen grapes decreased with intercellular CO2 mole fraction (Ci) decreasing under 4 g·L-1 salt stress, so stomatal limitation was one of the main reasons for reducing Pn under 4 g·L-1 salt stress. However, under 8 g·L-1 salt stress, the Pn decreased with the Ci increased, so the non-stomatal limitation became the main factory caused the decrease of Pn. The original fluorescence (Fo) gradually rose while Y(Ⅱ), qP and Fv′/Fm′ gradually decreased both Marselen/101-14 and own-rooted Marselen grapes with the increasing of mass concentration of NaCl, which suggested that NaCl stresses caused reaction center of PSⅡdamaged and electron transfer of the reaction center inhibited. However, the change amplitude of chlorophyll fluorescence parameters in Marselen/101-14 leaves was smaller than own-rooted Marselen in same NaCl stress, so the damage to PSⅡ reaction center of Marselen/101-14 was less than own-rooted Marselen, which was the probable reason why the Pn of Marselen/101-14 was higher than own-rooted Marselen under NaCl stresses.