Effects of shading on squash seedlings’ morphological and photosynthetic physiological characteristics
研究了不同遮光处理对西葫芦幼苗形态及光合生理特性的影响.结果表明,在60%透光率条件下，西葫芦幼苗具有较高的相对生长率、净光合速率、气孔导度、蒸腾速率、单叶水分利用效率、饱和蒸汽压、表观量子效率和叶绿素含量，而胞间CO2浓度较低；西葫芦幼苗具有较高的光饱和点(1 125 μmol·m-2·s-1)、较低的光补偿点(15.2 μmol·m-2·s-1).弱光下西葫芦幼苗较耐低浓度CO2，而强光下的幼苗较耐高浓度CO2.60%透光率下西葫芦幼苗叶片丙二醛和脯氨酸含量最低，而过氧化物酶和过氧化氢酶活性则最高.
The study of squash seedlings’ morphological and photosynthetic physiological characteristics under different shading showed that under 60% light transmittance,their relative growth rate,net photosynthetic rate (Pn),stomatal conductance (Gs),transpiration rate (EVAP),water use efficiency (WUE),saturation steam pressure (MBR),apparent quantum yield of photosynthesis (AQY),and chlorophyll contents were higher,while the intercellular CO2 concentration (Ci) was lower,compared with those under 20% light transmittance and CK.The seedlings under 60% light transmittance had a higher light saturation point (1 125 μmol·m-2·s-1) but a lower light compensation point (15.2 μmol·m-2·s-1).Squash seedlings under lower light intensity could endure lower concentration of CO2,while those under higher light intensity could endure higher concentration of CO2.Under 60% light transmittance,the malondialdehyde (MDA) and praline (Pro) contents were the lowest,while the peroxidase (POD) and catalase (CAT) activities were the highest.
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