不同密度下牛膝叶绿素荧光特性比较

Chlorophyll fluorescence characteristics of Achyranthes bidentata under different planting densities

在大田条件下,测定了不同密度下(A:500 000;B:330 000;C:250 000;D:200 000株.hm-2)牛膝(Achyranthes bidentata)的叶面积动态和倒二叶叶绿素含量、叶绿素荧光动力学参数以及根产量和牛膝多糖含量,了解了不同密度下牛膝的叶绿素荧光特性,为牛膝规范化种植提供理论依据。结果表明:不同密度下叶面积指数和叶绿素含量最高值均在苗后45 d,分别为A>B>C>D和B>C>A>D;光系统Ⅱ中的Fv/Fo、Fv/Fm、ФPSⅡ、qP、ETR均是先上升后下降,qN则升高;同一生育时期B处理Fv/Fo、Fv/Fm、ФPSⅡ、qN和ETR则表现为最高,且B处理受强光抑制的程度最小,B处理表现较高的光合作用;根产量和牛膝多糖含量与Fv/Fo、Fv/Fm呈正相关,与qN呈负相关;在出穗55 d,qN与多糖含量达显著负相关;B处理为最适密度。

In order to supply the theoretical basis for the normalized planting of Achyranthes bidentata, a field determination on the leaf area, chlorophyll content of the 2nd leaf, and dynamic parameters of chlorophyll fluorescence, as well as the root yield and plant polysaccharide content of A. bidentata under different planting densities （A： 500 000 plants · hm^- 1, B： 330 000 plants · hm^ - 1, C ： 250 000 plants · hm^-1, D ： 200 000 plants · hm^-1 ） was made. The results showed that under different planting densities, the maximum values of leaf area index and chlorophyll content were all appeared at the 45 th day of post-emergence, with the order of A 〉 B 〉 C 〉 D and B 〉 C 〉 A 〉 D, respectively. The Fv/Fo, Fv/Fm, ФpsⅡ, qP, and ETR of photosystem Ⅱ increased first and decreased then, while the qN kept increasing. At the same growth period, treatment B had the highest FiFo, Fv/Fo, ФpsⅡ, qN and ETR, and displayed the least restriction from high light and better performance of photosynthesis. The root yield and plant polysaccharide content were correlated positively with Fv/Fo , and Fv/Fm, and negatively with qN. At the 55th day of spike bringing forth, the qN was correlated negatively with plant polysaccharide content. It was suggested that treatment B was the most suitable planting density.