【摘要】 在设施基质栽培条件下,研究了营养液中120、240及360 mg.L-13个钾素水平对网纹甜瓜‘甜甜1号’叶片光合特性及叶绿体亚显微结构的影响.结果表明,营养液中钾素水平过低(120 mg.L-1)或过高(360 mg.L-1)均导致网纹甜瓜叶片净光合速率下降,使叶绿体片层结构混乱、变形和片层数减少,但对CO2补偿点(70μl.L-1)、饱和CO2(600μl.L-1)、光补偿点(50μmol.m-2.s-1)无显著影响.适宜的钾素水平能显著提高叶片的饱和光强、羧化效率和表观量子效率,3个指标分别为1 200μmol.m-2.s-1、0.1364和0.0237.在试验条件下,提高温室内基质栽培网纹甜瓜叶片光合效率的最适钾素水平为240 mg.L-1.更多还原

【Abstract】 With soilless culture in greenhouse,this paper studied the effects of three potassium(K) levels(120,240,and 360 mg·L-1) on the photosynthetic characteristics and chloroplast submicroscopic structure of muskmelon cv.’Tiantian No.1’ leaves.The results showed that at low(120 mg·L-1) and high(360 mg·L-1) K levels,the net photosynthetic rate(Pn) decreased,chloroplast lamellar structure disordered,and lamella number decreased.No significant effects were observed on CO2 compensation point(70 μl·L-1),saturation CO2 for photosynthesis(600 μl·L-1) and light compensation point(50 μmol·m-2·s-1) at the three K levels.The saturation light for photosynthesis,carboxylation efficiency and apparent quantum yield at 240 mg·L-1 K level were significantly higher,being 1 200 μmol·m-2·s-1,0.1364 and 0.0237,respectively.Under the conditions of this study,the optimal K level in the nutrient solution for muskmelon soilless culture was 240 mg·L-1.更多还原