摘要 | 以杞柳(Salix integra Thunb.)4个品种‘大红头’(‘Dahongtou’)、‘一枝笔’(‘Yizhibi’)、‘黄皮柳’(‘Huangpiliu’)和‘庄坞柳’(‘Zhuangwuliu’)为材料,比较了低浓度(10 μmol·L-1 CdCl2)和高浓度(50 μmol·L-1CdCl2)Cd处理下叶片的光合色素含量、叶绿素荧光参数和Cd含量变化,探讨叶片Cd含量与光合色素含量和叶绿素荧光参数间的相关性,并基于逐步回归函数,构建叶片Cd含量预测模型。结果显示:低浓度和高浓度Cd处理均导致杞柳叶片的叶绿素a、叶绿素b和总叶绿素以及类胡萝卜素含量出现不同程度的下降,其中,类胡萝卜素含量降幅较大,降幅最高达59.71%(‘庄坞柳’)。不同浓度Cd处理使杞柳叶片PSⅡ最大光化学效率(Fv/Fm)、相对电子传递速率(rETR)和PSⅡ实际光量子产额〔Y(Ⅱ)〕出现不同程度的降低,抑制了PSⅡ反应中心的活性;Cd处理下‘大红头’、‘一枝笔’和‘庄坞柳’叶片调节性能量耗散的量子产额〔Y(NPQ)〕和非调节性能量耗散的量子产额〔Y(NO)〕明显增加,光保护能力增强。双因素方差分析结果显示:Cd处理对杞柳叶片光合色素含量和叶绿素荧光参数有极显著影响,但品种仅对最大荧光(Fm)、初始荧光(Fo)、Fv/Fm值和非光化学淬灭系数(qN)有显著或极显著影响;品种和Cd处理对叶片Cd含量有显著或极显著影响。相关性分析结果显示:杞柳叶片Cd含量与叶绿素a含量(X1)、叶绿素b含量(X2)、总叶绿素含量(X3)、类胡萝卜素含量(X4)、Fo值(X5)和Fv/Fm值(X6)存在极显著相关性(相关系数绝对值大于0.8)。基于6个变量进行多元逐步回归,初步构建了杞柳叶片Cd含量(Y)预测模型Y=1 928.761-128.842X1-2 005.500X6(R2=0.850)。 |
Abstract | Taking four cultivars of Salix integra Thunb. namely ‘Dahongtou’, ‘Yizhibi’, ‘Huangpiliu’ and ‘Zhuangwuliu’ as materials, variations of photosynthetic pigment contents, chlorophyll fluorescence parameters and Cd content in leaves under low concentration (10 μmol·L-1 CdCl2) and high concentration (50 μmol·L-1 CdCl2) of Cd treatments were compared, the correlations of Cd content with photosynthetic pigment contents and chlorophyll fluorescence parameters of leaves were discussed, and a prediction model for Cd content in leaves was constructed based on stepwise regression function. The results show that low concentration and high concentration of Cd treatments both lead to decrease of contents of chlorophyll a, chlorophyll b, total chlorophyll and carotenoid of S. integra leaves to different degrees, in which, the decrement of carotenoid content is relatively large, which reaches as high as 59.71% (‘Zhuangwuliu’). Different concentrations of Cd treatments lead to decrease of maximum photochemical efficiency of PSⅡ (Fv/Fm), relative electron transport rate (rETR) and effective quantum yield of PSⅡ 〔Y(Ⅱ)〕 of S. integra leaves to different degrees, and inhibit the activity of PSⅡ reactive center; quantum yield of regulated energy dissipation 〔Y(NPQ)〕 and quantum yield of nonregulated energy dissipation 〔Y(NO)〕 of leaves of ‘Dahongtou’, ‘Yizhibi’ and ‘Zhuangwuliu’ evidently increase under Cd treatment, and photoprotection ability increase. The result of two-way ANOVA shows that Cd treatment has extremely significant effects on photosynthetic pigment contents and chlorophyll fluorescence parameters of S. integra leaves, but cultivar has significant or extremely significant effects only on maximum fluorescence (Fm), initial fluorescence (Fo), Fv/Fm value and nonphotochemical quenching coefficient (qN); cultivar and Cd treatment have significant or extremely significant effects on Cd content in leaves. The correlation analysis result shows that there are extremely significant correlations (the absolute values of correlation coefficients are greater than 0.8) of Cd content with chlorophyll a content (X1), chlorophyll b content (X2), total chlorophyll content (X3), carotenoid content (X4), Fo value (X5) and Fv/Fm value (X6) of S. integra leaves. Multiple stepwise regression is conducted based on six variables, and the prediction model Y=1 928.761-128.842X1-2 005.500X6 (R2=0.850) for Cd content (Y) in leaves of S. integra is preliminarily established. |
关键词 | 杞柳; Cd积累; 光合色素含量; 叶绿素荧光参数; 预测模型 |
Key words | Salix integra Thunb.; Cd accumulation; photosynthetic pigment content; chlorophyll fluorescence parameter; prediction model |
作者 | 王树凤1, 王松2, 舒婉钦1,3, 陈光才1 |
所在单位 | 1. 中国林业科学研究院亚热带林业研究所, 浙江 杭州 311400; 2. 台州市林业技术推广总站, 浙江 台州 318000;3. 中南林业科技大学林学院, 湖南 长沙 410004 |
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基金项目 | 国家自然科学基金面上项目(31770653) |