采用营养液栽培法,比较分析了根际高温(35 ℃)处理0、3 和5 d 以及恢复5 d 后黑籽南瓜(Cucurbita ficifolia Bouché)、‘春秋王2 号’黄瓜(Cucumis sativus ‘Chunqiuwang No. 2 ’)、‘兴蔬’丝瓜(Luffa cylindrica ‘Xingshu’)、‘五叶香’丝瓜(Luffa cylindrica ‘Wuyexiang’)和‘傲美’苦瓜(Momordica charantia ‘Aomei’)幼苗的生长及叶片光合和叶绿素荧光参数的变化。结果表明:与对照(25 ℃)相比,在高温处理期间及恢复期间,黑籽南瓜、‘春秋王2 号’黄瓜和‘傲美’苦瓜的株高、茎粗、叶面积、叶绿素相对含量(SPAD)以及叶片净光合速率(Pn)、气孔导度(Gs)、胞间CO2 浓度(Ci)、蒸腾速率(Tr)、PS域的光能捕获效率(Fv’/ Fm’)、PSⅡ的实际光化学效率(ФPS域)、实际光化学量子产量(Yield)、表观光合电子传递速率(ETR)、光化学猝灭系数(qP)及PSⅡ用于光化学反应的能量比例(P)总体上均显著低于对照;而‘五叶香’丝瓜的上述指标大多无明显变化,但其非光化学猝灭系数(qN)及PS域用于天线色素热耗散的能量比例(D)均低于对照;‘兴蔬’丝瓜的各项指标在高温处理期间均有不同程度的降低或升高,但在恢复5 d 后各项指标均接近或高于对照。研究结果表明:5 种瓜类作物对根际高温的耐受性有明显差异。其中,黑籽南瓜和‘春秋王2 号’黄瓜对根际高温的耐性最差;2 个丝瓜品种特别是‘五叶香’丝瓜的耐性较强,可作为耐高温瓜类作物的砧木。

By hydroponic cultivation method, changes of growth, leaf photosynthetic and chlorophyll fluorescence parameters of Cucurbita ficifolia Bouché, Cucumis sativus ‘Chunqiuwang No. 2’, Luffa cylindrica ‘Xingshu’, Luffa cylindrica ‘Wuyexiang’and Momordica charantia ‘Aomei’ seedlings after treated by high temperature (35 ℃) in rhizosphere for 0, 3 and 5 d and recovered for 5 d were compared and analyzed. The results show that compared to the control (25 ℃), during high temperature treating and recovering periods, plant height, stem diameter, leaf area, chlorophyll relative content (SPAD), and leaf net photosynthetic rate (Pn), stomatal conductance (Gs), intercellular CO2 concentration (Ci), transpiration rate ( Tr), excitation energy capture efficiency of PS Ⅱ( Fv’/ Fm’), actual photochemical efficiency of PS Ⅱ( ФPSⅡ), actual photochemical quantum yield ( Yield), apparent photosynthetic electron transport rate (ETR), photochemical fluorescence quenching coefficient (qP) and energy fraction of PS Ⅱused for photochemical reaction ( P) of C. ficifolia, C. sativus ‘Chunqiuwang No. 2’and M. charantia ‘Aomei’are generally significantly lower than those of the control. While most of above indexes of L. cylindrica ‘Wuyexiang’do not change obviously, but its non-photochemical quenching coefficient (qN) and energy fraction of PS Ⅱused for heat dissipation of antenna pigment (D) are lower than those of the control. During high temperature treating period, every index of L. cylindrica ‘Xingshu’decreases or increases in different degrees, but that is close to or higher than the control after recovered for 5 d. It is suggested that there is obvious difference in tolerance to high temperature in rhizosphere among five cucurbit crops. In which, tolerances of C. ficifolia and C. sativus ‘Chunqiuwang No. 2’are the worst, while tolerances of two cultivars of L. cylindrica, especially L.cylindrica ‘Wuyexiang’are stronger, and it can be used as rootstock of cucurbit crops of resisting high temperature stress.