| 摘要: |
| 【目的】对高温胁迫下辣椒幼苗的形态及其抗逆生理响应进行比较分析，为辣椒苗期耐热性鉴定提供参考。【方法】以辣椒耐热品系R9和热敏品系B6为试材，研究昼/夜温度为38 ℃/28 ℃高温处理7 d内，辣椒丙二醛（MDA）含量、脯氨酸（Pro）含量、超氧化物歧化酶（SOD）活性、过氧化物酶（POD）活性的变化及7 d后的生长差异。【结果】高温胁迫下，除了幼苗茎粗外，2个辣椒品系的株高，地上部和地下部干、鲜质量以及壮苗指数均显著低于常温对照（昼/夜温度为25 ℃/20 ℃），且热敏品系B6幼苗生长受阻程度高于耐热品系R9。高温胁迫下，2个辣椒品系叶片的Pro含量均增加，表现为耐热品系增幅大于热敏品系；SOD和POD活性呈现出先升高后降低的趋势，但品系R9的SOD和POD酶活性均显著高于品系B6；品系R9的MDA含量增幅低于品系B6。【结论】高温胁迫下，SOD、POD 活性及Pro和MDA含量的变化在不同辣椒品系间有很大差异，可以作为辣椒耐热鉴定的辅助生理指标。 |
| 关键词: 辣椒 高温胁迫 壮苗指数 逆境生理响应 |
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| 基金项目:国家自然科学基金项目（31272163，31000906）；陕西省农业科技攻关项目（2010K01-25-1）；西北农林科技大学基本科研业务费项目（QN2011090） |
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| Responses of growth and physiology of pepper (Capsicum annuum L.) seedlings to high temperature stress |
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| Abstract: |
| 【Objective】The responses of growth and physiology between two different cultivars of pepper (Capsicum annuum L.) to high temperature stress were compared.【Method】Heat-resistant Cv.R9 and heat-susceptible Cv.B6 were used to study the responses of malondialdehyde content,proline content,superoxide dismutase activity,peroxidase activity as well as growth index to high temperature of 38 ℃/28 ℃ for 7 days.【Result】The results showed compared with normal temperature (25 ℃/20 ℃),seedling height,fresh weight in root and shoot,dry weight in root and shoot as well as seedling index under heat stress significantly declined in both heat-resistant Cv.R9 and heat-susceptible Cv.B6. But the effects on Cv.B6 were severer than Cv.R9.Besides,high temperature also increased the proline contents in both cultivars,and the magnitude in Cv.R9 was bigger than that of the Cv.B6.Both SOD and POD activities showed a trend of increase before decrease,and heat-resistant variety was higher than the heat-susceptible variety,whereas the malondialdehyde content in Cv.R9 was lower than the Cv.B6.【Conclusion】SOD and POD activities,proline content and MDA content were significantly correlated with heat stress time and pepper cultivars.These four indexes can be used to identify heat tolerance of pepper. |
| Key words: pepper heat stress seedling index physiological characteristics |
