盐分胁迫对小麦光合生产及产量的影响

Effects of salt stress on photosynthetic production and yield of wheat

为了分析小麦光合生产及产量对盐分胁迫的响应,以弱筋品种宁麦13和中筋品种扬麦16为材料,研究不同盐浓度处理[0(对照)、0.075%、0.150%、0.225%、0.300%、0.375%和0.450%]下2个小麦品种的出苗率、光合特性、叶绿素荧光特性、干物质和产量形成的特点。结果显示:随盐浓度的增加,2个小麦品种的出苗率均呈降低趋势。在盐浓度≤0.225%时,2种小麦的净光合速率(P n)、气孔导度(C s)均随盐浓度的增加无显著变化;当盐含量>0.225%时,2种小麦净光合速率、气孔导度随着盐浓度的增加而降低,胞间CO2浓度(C i)随盐浓度增加而升高。不同盐浓度处理下2种小麦的PSⅡ最大光化学效率(F v/F m)、初始荧光(F o)、光化学猝灭系数(qP)均随盐浓度的增加而降低。当盐含量>0.225%时qP显著低于对照(P<0.05);在盐含量≤0.225%时,2种小麦的非光化学猝灭系数(NPQ)均显著高于对照(P<0.05)。2种小麦的干物质和产量均呈现出在低盐浓度(≤0.225%)处理下增加和高盐浓度(>0.225%)处理下显著降低的趋势。总之,当盐浓度为0.225%时,小麦的光合生产和产量均达到最高值。

Two wheat varieties, weak gluten wheat Ningmai 13 and medium gluten wheat Yangmai 16, were used to study the effects of different salt concentrations（0,0.075%,0.150%,0.225%,0.300%,0.375% and 0.450%）on germination rates, photosynthetic rates, chlorophyll fluorescent parameters, dry matter productions and yields. The germination rates of two wheat varieties showed a decrease response to the increase of salt concentration. When the salt concentration was less than or equal to 0.225%, the net photosynthetic rate （Pn） and stomatal conductance （Cs） did not change significantly with the increase of salt concentration. When the salt concentration was greater than 0.225%, Pn and Cs declined with the increase of salt concentration, however, the intercellular CO2 concentration （Ci） increased. Under the salt stress, the ratio of the variable to maximum fluorescence （Fv / Fm）, the minimal fluorescence （Fo） and the photochemical quenching coefficient （qP） all dropped with the increase of salt concentration. When the salt concentration was greater than 0.225%, qP was lower than that of control （P〈0.05）. The non-photochemical quenching coefficients of two wheat cultivars （NPQ） were higher than that of control （P〈0.05） when the salt concentration was less than or equal to 0.225%. The yields and dry weights of two wheat varieties increased in the low-salt （ 臆0.225%） treatment and decreased significantly in the high salt （〉0.225%） treatment. In conclusion, when the salt concentration was 0.225%, photosynthetic production and yield of wheat reached the highest.