低温弱光对不同黄瓜品种幼苗光合作用的影响

 在低温(15 ℃) 弱光(100μE·m^-2·s^-1) 的胁迫下, 供试黄瓜品种幼苗的光补偿点开始升高, 叶绿素a 荧光动力学的有关参数Fv/ Fm、qp 、ΦPS Ⅱ ( Y) 值和参与光合作用碳同化的关键酶RuBP 羧化酶活性明显下降。这一结果表明PS Ⅱ的原初光能转换效率和电子传递以及碳同化均受到抑制, 从而使幼苗对弱光的利用能力下降。然而在逆境的诱导下, 黄瓜幼苗的适应性逐渐增强, 上述各项指标恢复到处理前的水平。试验结果还表明, 保护地品种对低温弱光逆境的调节适应能力高于露地品种。

Effects of Low Temperature and Low Light Intensity Stress on Photosynthesis in Seedlings of Different Cucumber Varieties

Under the stress of low temperature (15 ℃) and low light intensity (100μE·m^-2·s^-1) , the photosynthetic light compensation point of cucumber seedlings went up at the beginning of treatment , some parameters of chlorophyll a fluorescence such as Fv/ Fm , qp , ΦPS Ⅱ ( Y) decreased obviously , and the activity of RuBPCase was also reduced. This results indicated that the primary light energy conversion of PS Ⅱ, electron transport and carbon assimilation of cucumber seedlings had been inhibited , thus the capacity of its utilizing low light intensity went down. However , afterthe induction of stress , the adaptability of cucumber seedlings increased , and the above parameter reversed the level before stress treatment . The results also showed that the adaptability of greenhouse varieties was higher than that of open field varieties.