【作者】 王虹；

【导师】 姜卫兵；

【作者基本信息】 南京农业大学 ， 果树学， 2008， 硕士

【摘要】 干旱是众多环境胁迫中最重要的因素之一,它能引起植物巨大的生理变化。光合作用是植物最重要的生理过程,对干旱胁迫高度敏感,但在不同植物之间有一定的差异。彩叶植物作为一类特殊的观赏植物,在园林绿化中的应用越来越广泛。果树中的一些如红叶桃等也属于彩叶植物。因此通过研究红叶桃对干旱胁迫的生理反应,不但有助于揭示红叶桃适应逆境的生理机制,更有助于生产上采取切实可行的技术措施,提高红叶桃的抗逆性或保护其免受伤害,为红叶桃的生长创造有利条件。本研究以绿叶桃品种为对照,研究了不同程度干旱胁迫下红叶桃的逆境生理指标、光合生理特性及叶绿素荧光参数等的变化。结果表明:1.夏季干旱胁迫下红叶桃光合特性及相关生理指标的变化(1)随着胁迫时间的延长和胁迫程度的加深,红叶桃和绿叶桃叶片相对含水量、光合色素含量以及P_n日积分值等光合基本指标都受到了更深程度的抑制;而花色素苷含量、细胞膜透性、丙二醛含量及脯氨酸含量大幅增加,抗氧化酶系统(SOD、POD、CAT)活性表现为先升后降的趋势。(2)夏季干旱胁迫下,红叶桃与绿叶桃表观量子效率(AQY)、羧化效率(CE)下降,红叶桃与绿叶桃光合受抑,初期中度干旱表现为气孔限制,重度干旱则表现为非气孔限制,后期均为非气孔限制。光饱和点(LSP)降低、光补偿点(LCP)升高,可利用的光强范围变小。(3)对叶绿素荧光参数的分析可知,随着胁迫时间的延长和胁迫程度的加深,红叶桃F_v/F_m、qp、Yield、ETR等参数逐渐下降,而NPQ却逐渐升高(4)灰色关联分析表明,夏季对红叶桃与绿叶桃P_n影响最大的气象因子为大气温度,而干旱胁迫下对红叶桃P_n影响最大的气象因子也是大气温度,绿叶桃则为大气水汽压。2.秋季干旱胁迫下红叶桃光合特性及相关生理指标的变化(1)随着胁迫时间的延长和胁迫程度的加深,红叶桃和绿叶桃叶片相对含水量、光合色素含量以及P_n日积分值等光合基本指标都受到了更深程度的抑制;而花色素苷含量、细胞膜透性、丙二醛含量及脯氨酸含量大幅增加,抗氧化酶系统(SOD、POD、CAT)活性表现为先升后降的趋势。(2)秋季干旱胁迫下,红叶桃与绿叶桃表观量子效率(AQY)、羧化效率(CB)下降,红叶桃与绿叶桃光合受抑主要为非气孔限制。光饱和点(LSP)降低、光补偿点(LCP)升高,可利用的光强范围变小。(3)对叶绿素荧光参数的分析可知,随着胁迫时间的延长和胁迫程度的加深,红叶桃F_v/F_m、qp、Yield、ETR等参数逐渐下降,而NPQ却逐渐升高(4)秋季对红叶桃与绿叶桃P_n影响最大的气象因子为大气温度,而干旱胁迫下则主要为大气水汽压。3.比较夏秋季节干旱胁迫对红叶桃光合特性影响的差异比较夏秋季节干旱胁迫对红叶桃细胞膜透性、MDA含量、Chl含量、Ant含量、抗氧化酶(SOD、POD、CAT)活性、P_n日均值、WUE日均值及F_v/F_m等指标影响,可知,由于夏季干旱胁迫下红叶桃Chl含量下降的幅度比秋季低,Ant上升的幅度比秋季高,使其P_n日均值及F_v/F_m下降的幅度低于秋季。结合夏秋季节气象因子的分析,得出夏季干旱胁迫对红叶桃膜系统、光合机构及光系统Ⅱ的伤害程度比秋季小。更多还原

【Abstract】 Drought is one of the most important ingredients of environmental stresses, which can arose tremendous physiological change of plant. Photosynthesis is the most important physiological process, which is extraordinary sensitivity to drought stresses and have definite diversity among different plants. Color-leafed plants, as a group of special ornamental plants, applied more and more extensively in landscape greening. Some mutation of the fruit tree, such as Red-leaf peach, is belong to Color-leafed plants. So the studying of physiological responses to drought stress is not only helpful to open out physiological mechanism of red-leaf peach to stress, but also redounding to the ability of resisting stress or protecting Red-leaf peach from stress, with the feasible technological measures. In this paper, with the Green-leaf peach as control, we studied on the changes of index of stress physiology, Photosynthetic characteristic and Chlorophyll fluorescence characteristic of red-leaf peach under drought of different degrees. The results showed that:1 Studying on Photosynthetic characteristic and relative physiology index of Red-leaf peach under drought stress in summer（1）Along with the stress time extended and stress degree increased, leaf relative water content, photosynthetic pigment content and the diurnal integral value of P_n in Red-leaf peach and Green-leaf-peach were restrained in different degree, but the anthocyanin content, membrane permeability ,MDA content and Pro content increased distinctly. And antioxidant enzymes（SOD,POD,CAT）activity first arised and then declined. （2）Under drought stress in summer, AQY and CE of Red-leaf peach and Green-leaf-peach went down. Moreover the photosynthesis restraining was due to stomatal limitation early under Medium drought while the photosynthesis restraining was due to nonstomatal limitation under heavy drought. The declining of LSP and rising of LCP made the available light arrange shortened.（3）The analysis of Chlorophyll fluorescence characteristic showed that as the stress time went on and stress degree increased, the value of F_v/F_m,qP,Yield,ETR in Red-leaf peach and Green-leaf-peach decreased inapprent, while the value of NPQ rose up. （4）The gray relational grade analysis showed that the relationship between climate factors and P_n in Red-leaf peach and Green-leaf-peach were T_a in summer. While the relationship between climate factors and P_n in Red-leaf peach under drought stress were also T_a, in Green-leaf peach were V_p.2 Studying on Photosynthetic characteristic and relative physiology index of Red-leaf peach under drought stress in autumn（1）Along with the stress time extended and stress degree increased, leaf relative water content, photosynthetic pigment content and the diurnal integral value of P_n in Red-leaf peach and Green-leaf-peach was restrained in different degree, but the anthocyanin content, membrane permeability,MDA content and Pro content increased distinctly. And antioxidant enzymes（SOD,POD,CAT）activity first arised and then declined. （2）Under drought stress in autumn, AQY and CE of Red-leaf peach and Green-leaf-peach went down. Moreover the photosynthesis restraining was due to nonstomatal limitation. The declining of LSP and rising of LCP made the available light arrange shortened.（3）The analysis of Chlorophyll fluorescence characteristic showed that as the stress time went on and stress degree increased, the value of F_v/F_m,qP,Yield,ETR in Red-leaf peach and Green-leaf-peach decreased inapprent, while the value of NPQ rose up. （4）The gray relational grade analysis showed that the relationship between climate factors and P_n in Red-leaf peach and Green-leaf-peach was T_a in summer. While the relationship between climate factors and P_n in Red-leaf peach under drought stress were V_p.3 Comparison of the effect on Photosynthetic characteristic of Red-leaf peach under drought stress in summer and autumnComparison of Membrane Permeability、MDA content、Chlcontent、Ant content、antioxidant enzymes（SOD,POD,CAT）activity ,P_n day average value、WUE day average value,F_v/P_m day average value of Red-leaf peach under drought stress in summer and autumn.The results showed that the decrease range of Chl content in Red-leaf peach was higher in summer than in autumn and the ascending range of Ant content in Red-leaf peach is higher in summer than in autumn,so the decrease range of P_n day average value and F_v/F_m day average value was lower than in autumn. By combining with meteorological factors analysis showed that Membrane Permeability、Photosynthetic Apparatus and PhotosystemⅡof Red-leaf peach under drought stress in summer were damaged lighter than in autumn.更多还原