呼伦贝尔草原三种优势植物叶绿素荧光特性的比较

Comparison of Chlorophyll Fluorescence Characters of Three Dominant Plants in Hulunbeier Typical Steppe

利用MONITORING—PAM荧光仪对呼伦贝尔典型草原三种优势植物羊草、草地麻花头和茵陈蒿的叶绿素荧光特征进行比较,结果表明:三种优势植物的叶绿素荧光参数光适应下最大荧光产量(Fm′)、实际光化学效率(ΦPSⅡ)、表观光合电子传递速率(ETR)的日变化趋势基本一致,但存在明显的种间差异,其日均值为茵陈蒿>草地麻花头>羊草。茵陈蒿的Fm′和ETR的变化幅度明显大于羊草和草地麻花头,而ΦPSⅡ变化幅度又明显小于后二者。茵陈蒿ETR值呈双峰型变化,在12∶00和14∶00出现两次峰值,分别为257.5μmol/m2.s和230.8μmol/m2.s,与羊草和草地麻花头的单峰型变化趋势有区别。三种优势植物中,茵陈蒿具有更强的光能捕获能力和光抑制自我保护机制,草地麻花头次之,最后是羊草。

The chlorophyll fluorescence characters of Leyrnus chinensis, Serratula centauroides and Artemisia capillaris were detected by using MONITORING PAM multi-channel chlorophyll fluorometer in Hulunbeier typical steppe. The results showed that the diurnal change trends of Fro＇, ФPSII and ETR of three dominant plants were basically the same, but there were significant differences among species, the daily mean values of Fm＇, ФPSII and ETR in three plants were in descending order： Artemisia capillaris〉 Serratula centauroides〉Leymus chinensis. The variation scope of Fm＇ and ETR in Arternisia capillaris was larger than that of Leymus chinensis and Serratula centauroides ; nevertheless, the variation scope of ФPSII in Artemisia capillaris was smaller than that of Leymus chinensis and Serratula centauroides. The value of ETR in Artemisia capillaris changed in terms of double-peaks, which was different from that of the others; two single peaks at 12 ： 00 and 14 ： 00 were observed in Artemisia capillaris, the values were 257.5μmol/m2 @ s and 230.8μmol/m2 @ s, respectively. Arternisia capillaris had the strong ability of trapping light and had better self-protection mechanism of photoinhibition, Serratula centauroides was the second, Leymus chinensis was the last.