摘要
阔叶十大功劳、狭叶十大功劳及南天竹同为小檗科植物,其叶片表观性状存在较大差异。为了考察上述3种植物叶片SPAD值与叶绿素的相关性,运用SPAD-502Plus叶绿素仪和分光光度法分别测定这3种植物叶片的叶绿素含量,并引入叶鲜质量与叶面积比(ratio of leaf fresh mass and leaf area,SLW)作为叶片厚薄的特征参数;再应用通径分析进一步探讨叶片特征参数和各叶绿素参数对SPAD值的直接或间接影响,最后建立SPAD值与叶绿素a及叶绿素b和总叶绿素的线性函数、二次多项式函数、指数函数及乘幂函数的拟合方程,并根据决定系数(R2)确定最佳拟合曲线。研究表明:SPAD值与叶绿素含量在单位叶鲜质量表示下相关性不强,但在单位叶面积表示下成极显著相关;通过通径分析发现在考察的各参数中对SPAD值影响最大的是叶绿素a含量,说明SPAD-502Plus叶绿素仪有效地消除了叶片厚度等对测量结果的影响;在所建立的拟合方程中,SPAD值与叶绿素含量的非线性拟合效果要优于线性,并且不同种植物的最佳数学模型各有不同。上述分析说明,利用SPAD-502Plus叶绿素仪快速、无损地评估在体植物叶片的叶绿素含量是可行的。
Summary Determination of chlorophyll concentration has significance for photosynthesis and stress physiology since it is the main photosynthetic pigment in higher plant leaves. Previous researches have shown high correlation between leaf chlorophyll concentration and SPAD values, obtained by SPAD-502Plus chlorophyll meter. Path analysis also has been used for analyzing the direct effect and indirect effect among various independent variables and dependent variable. There exist large differences in leaf characteristics among three species of Berberidaceae i. e Mahonia bealei （Fort.） Carr. , Mahonia fortunei （Lindl.） Fedde, and Nandina domestica. In order to study the correlation of SPAD values and chlorophyll concentration in these three species, the chlorophyll concentration was measured by SPAD-502Plus chlorophyll meter and ultraviolet spectrophotometer. The chlorophyll concentration was expressed as per unit leaf area or per unit leaf fresh mass respectively; a parameter SLW （ratio of leaf fresh mass and leaf area）. was introduced to describe the characteristic of leaf thickness. The effects of both the leaf apparent characteristics and chlorophyll parameters on SPAD values were further investigated by path analysis. Moreover, the empirical relationships between the SPAD values and the concentration of chlorophyll a （Chla）, chlorophyll b （Chlb） and total chlorophyll （TChl） were determined by a linear function, a second-order polynomials function, an exponential function and a power function to calculate the R2 decision value based optimal fitting curve. For all three species, when chlorophyll concentration was expressed as per unit leaf area, it showed significant correlation with SPAD values. The SPAD values showed higher correlation with the concentration of Chla than Chlb in M. bealei and M. fortunei, and the result was opposite in N. dornestica. The positive correlation between parameter SLW and SPAD values was found among the three species and was significant in M. bealei and M. fortunei, which indicated that thick leaves contained higher chlorophyll concentration. Furthermore, SLW showed higher positive correlation with carotenoid （Car） than Chla, Chlh, TChl in all three species, which could be related to the stress resistance of Car; The path analysis led to two fold discoveries： 1） The concentration of Chla had the greatest impact on SPAD values; 2） The SPAI〉502Plus chlorophyll meter could effectively eliminate the impact factors （e. g., leaf thickness）. A non-linear relationship between SPAD values and chlorophyll concentration was indicated by the empirical equations; nevertheless, the optimal equations o{ Chla, Chlb, and TChl in M. bealei. were exponential function, while the power function of Chla, TChl and the second-order polynomials function of Chlb in M. fortunei and N. domestica were observed. The correlation between SPAD values and chlorophyll concentration in three different species of Berberidaeeae indicats that the SPAD values can accurately reflect the chlorophyll concentration in higher plant leaves and the SPAD-502PIus chlorophyll meter can effectively eliminate the impact factors, so we propose that the SPArYS02Plus chlorophyll meter can be referred as a fast and nondestructive method to evaluate the chlorophyll concentration, and SPAD calibration curves shall commonly be parameterized as non linear relationship.
出处
《浙江大学学报（农业与生命科学版）》
CAS
CSCD
北大核心
2013年第3期261-266,共6页
Journal of Zhejiang University:Agriculture and Life Sciences
基金
国家自然科学基金资助项目(81202424)
关键词
SPAD值
叶绿素
相关性
通径分析
拟合方程
SPAD values
chlorophyll
correlation
path analysis
empirical equation
