试验通过高温、CO2加富下对温室嫁接黄瓜的形态特征、净光合速率、Rubisco羧化酶日变化及其不同时间内Rubisco羧化酶变化进行测定分析,旨在为夏秋季温室黄瓜高产优质栽培提供理论依据。结果表明,高温、CO2加富下温室嫁接黄瓜植株生长旺盛,株高、茎粗、叶面积、叶片厚度均明显高于其他处理。经过高温、CO2处理后的温室嫁接黄瓜,其Rubisco羧化酶活性日变化呈"双峰"曲线,第一个峰出现在上午9:00前后,第二个峰在下午15:00左右,并在两峰间13:00达到低谷,其日变化始终高于其他处理。常温条件下,CO2加富后在较低温度时(9:00),会抑制Rubisco羧化酶的活性,而温度升高后(13:00和15:00),可以提高Rubisco羧化酶的活性。单纯的高温会抑制Rubi-sco羧化酶的活性,而CO2加富后,可以提高Rubisco羧化酶的活性,显著地高于对照与常温、CO2处理。高温、CO2处理温室嫁接黄瓜净光合速率的变化与其Rubisco羧化酶活性的变化呈显著的正相关关系。CO2加富可以增加温室嫁接黄瓜叶片的净光合速率,即使9:00羧化酶的活性较低时,净光合速率也高于对照和单纯高温处理。CO2加富配合高温可以更有效地提高温室嫁接黄瓜的光合作用,进而促进了温室嫁接黄瓜植株的生长。
In the study, morphological features, net photosynthetic rate,diurnal changes of RuBPCase activity and RuBPCase activi- ties at different time points of grafted cucumbers under high temperature and elevated CO2 in greenhouse were measured and analyzed with the expectation to offer theoretical basis for cultivation of high - yield and quality greenhouse cucumbers in Summer and Autumn. The results demonstrated that the grafted cucumber in greenhouse with high temperature and elevated CO2 grew vigorously, stem height, stem diameter, leaf area and leaf thickness were significantly higher than other treatments. Diurnal changes of RuBPCase activity of grafted cucumber in greenhouse within high temperature and elevated COa was "Twin Peaks" curve, the first peak appear in around 9 : 00 am, the second peak appear in around 15:00 pm, and 13:00 to reach a trough in between the two peaks, RuBPCase activities at all time points under high temperature and enriched CO2 were significantly higher than other treatments. But the RuBPCase activity can be inhibited only with CO2 enrichment treatment under lower temperature (9:00) ; but with the temperature increasing (13:00 and 15: 190), the RuBPCase activity recovered and finally higher than control. The RuBPCase activity can also be inhibited because of high temperature, but the CO= enrichment treatment can offset the effect and finally increase the enzyme activity. This paper also demonstra- ted a significant positive correlation between net photosynthetic rate and RuBPCase activity of grafted cucumbers in greenhouse under high temperature and elevated COz treatment. It demonstrated that the high - temperature and CO2 enrichment treatment can effectively promote the RuBPCase activity, photosynthesis and growth of grafted cucumbers in greenhouse.