低温胁迫对紫花苜蓿幼苗生理特性的影响  

Effects of low temperature stress on the physiological characteristics of Medicago sativa seedlings

作　　者：马亚珺 杨国柱[1] 童永尚 刘增辉 MA Yajun;YANG Guozhu;TONG Yongshang;LIU Zenghui(Ecological Environment Engineering Research Center,Qinghai University,Xining 810016,China;College of Agriculture and Animal Husbandry,Qinghai University,Xining 810016,China;Academy of Animal and Veterinary Sciences,Qinghai University,Xining 810016,China)

机构地区：[1]青海大学生态环境工程研究中心,青海西宁810016 [2]青海大学农牧学院,青海西宁810016 [3]青海大学畜牧兽医科学院,青海西宁810016

出　　处：《青海大学学报》2022年第6期16-19,共4页Journal of Qinghai University

基　　金：中央财政林草科技推广示范项目“紫花苜蓿新品系原种更新复壮技术集成与示范”(青〔2020〕TG11)

摘　　要：为了探讨低温胁迫对青大1号紫花苜蓿幼苗生理特性的影响,将其幼苗置于0℃,分别低温胁迫6、12、24、48、72 h,以25℃为对照,通过测定低温胁迫下紫花苜蓿叶片生长及生理指标确定其抗寒生理特性。结果表明:相较于对照组,随着低温时间的延长,丙二醛含量呈先升高后降低直至平稳的趋势;随着低温时间延长,叶片中脯氨酸含量逐渐积累,在低温胁迫6 h处理下叶片脯氨酸含量最低,为0.019 1μg/g, 24 h处理下含量最高,为0.021 7μg/g,随后趋于平稳;在低温胁迫6 h处理下叶片叶绿素含量最高,48 h处理下叶绿素含量最低。通过相关性分析可知,随着低温处理时间的延长,青大1号紫花苜蓿叶片中叶绿素含量与脯氨酸含量呈极显著负相关(P<0.01),与丙二醛含量呈显著负相关(P<0.05),脯氨酸和丙二醛含量呈极显著正相关(P<0.01)。说明在低温胁迫过程中,紫花苜蓿幼苗的脯氨酸含量和丙二醛含量逐渐积累,可以反映出细胞膜脂过氧化程度。研究结果可为进一步开展紫花苜蓿的抗寒性研究提供理论依据。In order to explore the effects of low temperature stress on the physiological characteristics of Qingda No.1 Medicago sativa seedlings, the seedlings are stressed at 0 ℃ for 6,12,24,48,72 hours compared with 25 ℃.The physiological characteristics of cold resistance of the seedlings are determined by measuring the growth and physiological indexes of its leaves under low temperature stress.The results show that compared with the control group, the content of malondialdehyde increases first and then decreases until stable with the extension of low temperature time;the content of proline in the leaves gradually accumulates with the extension of low temperature time.The content of proline in the leaves is the lowest(0.019 1 μg/g)under 6 h low temperature stress and the highest(0.021 7 μg/g)under 24 h, and then tends to be stable;the chlorophyll content of leaves is the highest under 6 h low temperature stress and the lowest under 48 h.According to the correlation analysis, the chlorophyll content in the leaves is significantly negatively correlated with proline content(P<0.01)with the extension of low temperature time, and significantly negatively correlated with the content of malondialdehyde(P<0.05).The content of proline and malondialdehyde are significantly positively correlated(P<0.01).It indicates that the content of proline and malondialdehyde in Medicago sativa seedlings gradually accumulate during the process of low temperature stress, reflecting the degree of membrane lipid peroxidation.The results can provide a theoretical basis for further research on the cold resistance of Medicago sativa.

关 键 词：紫花苜蓿 低温胁迫 脯氨酸 丙二醛 叶绿素 

分 类 号：Q41[生物学—生理学]