| 摘要: |
| 【目的】分析湿热环境对黄瓜幼苗生长发育、光合作用、抗氧化生理及子房发育的影响，为黄瓜耐高温高湿鉴定及育种提供理论依据。【方法】以耐湿热黄瓜品种‘燕青’和喜冷凉黄瓜品种‘津春4号’为试验材料，设置常温常湿CK（28 ℃、空气湿度（RH）75%）、常温高湿T1（28 ℃、RH95%）、高温常湿T2（42 ℃、RH75%）和高温高湿T3（42 ℃、RH95%）4个处理，测定并比较各处理下2个黄瓜品种幼苗的光合特性、叶绿素荧光特性、抗氧化酶活性、活性氧含量、生长指标以及子房发育状况。【结果】T1处理下，2个黄瓜品种叶片的净光合速率（Pn）、胞间CO2浓度（Ci）和蒸腾速率（Tr）基本与CK差异不显著（P>0.05），仅气孔导度（Gs）显著（P<0.05）高于CK。T2和T3处理下，‘燕青’的Pn较CK明显下降，Gs和Ci极显著（P<0.01）下降，而Tr极显著（P<0.01）上升；‘津春4号’的Pn较CK极显著（P<0.01）下降，Gs明显下降，Tr极显著（P<0.01）上升，而Ci与CK差异不显著（P>0.05）。2个黄瓜品种的初始荧光（Fo）、最大荧光（Fm）、最大光化学效率（Fv/Fm）和非光化学猝灭系数（NPQ）在各处理间大多差异不显著（P>0.05），光系统Ⅱ实际光化学量子效率（ΦPSⅡ）、电子传递效率（ETR）和光化学猝灭系数（qP）仅T1处理与CK差异不显著（P>0.05），而T2和T3处理下，‘燕青’和‘津春4号’的ΦPSⅡ、ETR和qP较CK极显著（P<0.01）下降。2个黄瓜品种在T1处理下的超氧化物歧化酶（SOD）、过氧化物酶（POD）和过氧化氢酶（CAT）活性均与CK差异不显著（P>0.05），而在T2和T3处理下SOD、POD活性均极显著（P<0.01）低于CK，‘燕青’的CAT活性仅T3处理显著（P<0.05）低于CK，‘津春4号’的CAT活性T2和T3处理均与CK差异不显著（P>0.05）。‘燕青’的超氧阴离子（O-2·）和过氧化氢（H2O2）含量在各处理间均无显著差异（P>0.05）；‘津春4号’在T2和T3处理下O-2·含量显著（P<0.05）高于CK，而H2O2含量在各处理间无显著差异（P>0.05）。2个黄瓜品种在T1处理下的植株干质量、株高、茎粗、单叶面积和单叶干质量均与CK无显著差异（P>0.05）；T2和T3处理下，植株干质量、单叶面积和单叶干质量均较CK显著（P<0.05）下降，株高和‘津春4号’的茎粗则较CK显著（P<0.05）上升，而‘燕青’的茎粗仅T2处理较CK极显著（P<0.01）上升。2个黄瓜品种在处理9 d时，T2和T3处理下子房长度增量和子房直径增量均较CK极显著（P<0.01）下降。【结论】苗期高温高湿对黄瓜营养生长和生殖生长及生理都有显著抑制作用，且高温高湿伤害略大于高温常湿，常温高湿的影响相对最小。 |
| 关键词: 黄瓜幼苗 高温高湿 生理指标 形态指标 |
| DOI： |
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| 基金项目:国家重点研发计划项目（2016YFD0101705） |
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| Physiological response of cucumber seedlings to high temperature and humidity stress |
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TONG Peijiang,CHENG Zhihui,MENG Huanwen
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| Abstract: |
| 【Objective】Analyze the effects of humid and hot environment on the growth and development of cucumber seedlings,photosynthesis,antioxidant physiology and flower organ development to provide theoretical basis for the identification and breeding of cucumber resistance to high temperature and high humidity.【Method】The moist heat resistant variety ‘Yanqing’ and the cold resistant variety ‘Jinchun 4’ were used as experience materials.Set normal temperature and normal humidity CK (28 ℃,relative humidity (RH) 75%),normal temperature and high humidity T1 (28 ℃,RH95%),high temperature normal humidity T2 (42 ℃,RH75%) and high temperature and high humidity T3 (42 ℃,RH95%) to determine and compare 2 cucumber varieties seedlings’s photosynthetic characteristics and chlorophyll fluorescence characteristics,activities of antioxidant enzymes,contents of reactive oxygen species,growth index and ovary development situation.【Result】Under T1,the net photosynthetic rate (Pn),intercellular CO2 concentration (Ci) and transpiration rate (Tr) of 2 cucumber varieties were not significantly different from those of CK (P>0.05),only stomatal conductance (Gs) was significantly (P<0.05) higher than CK.Under T2 and T3,Pn of ‘Yanqing’ decreased significantly compared with CK,and Gs and Ci had the extremely significant (P<0.01) decrease while Tr had the extremely significant (P<0.01) rise;Pn of ‘Jinchun 4’ decreased extremely (P<0.01) compared with CK,Gs significantly(P<0.05) decreased,Tr extremely (P<0.01) increased,while Ci had no significant difference compared with CK.2 varieties’ minimal fluorescence (Fo),maximal fluorescence (Fm),maximal quantum yield (Fv/Fm) and non photochemical quenching coefficient (NPQ) were not significant (P>0.05) in most treatments,and actual photochemical efficiency (ΦPSⅡ),electron transfer rate (ETR) and photochemical quenching coefficient (qP),only in T1,had no significant difference with CK,while ΦPSⅡ,ETR and qP of ‘Yanqing’ and ‘Jinchun 4’ in T2 and T3 extremely (P<0.01) decreased.The activities of superoxide dismutase (SOD),peroxidase (POD) and catalase (CAT) of the 2 cucumber varieties under T1 were not significantly different (P>0.05) from those of CK.while SOD and POD activities under T2 and T3 were extremely(P<0.01) lower than CK,the CAT activity of ‘Yanqing’,only under T3,was significantly (P<0.05) lower than CK,and the CAT activity of ‘Jinchun 4’ was not significantly different (P>0.05) from that of CK at T2 and T3.There was no significant difference in superoxide anion (O-2·) and hydrogen peroxide (H2O2) content between treatments.Under T2 and T3,the O-2· content of ‘Jinchun 4’ was significantly higher (P<0.05) than CK,while the H2O2 content showed no significant difference among treatments.Under T1 treatment,the dry mass,plant height,stem diameter,leaf area and leaf dry mass of the two cucumber varieties were not significantly different from those of CK.Under T2 and T3,the plant dry mass,leaf area and leaf dry mass significantly (P<0.05) decreased compared with CK;the plant height and stem diameter of ‘Jinchun 4’ significantly (P<0.05) increased compared with CK;while the stem diameter of ‘Yanqing’ in T2 extremely (P<0.01) increased compared with CK.When the two cucumber varieties were treated for 9 d,the ovary length increment and ovary diameter increment under T2 and T3 treatments extremely (P<0.01) decreased compared with CK.【Conclusion】 High temperature and high humidity in seedling stage have significant inhibitory effects on vegetative growth,reproductive growth and physiology of cucumber,and the damage of high temperature and high humidity is slightly greater than that of high temperature and normal humidity,normal temperature and high humidity has least effect on cucumber seedlings. |
| Key words: cucumber seedlings high temperature and high humidity physiological indexes morphological indexes |
