不同光合类型植物光合作用的比较研究

Comparison of Photosynthetic Characteristics in Three Different Photosynthetic Plants

研究了相同条件下不同光合类型植物的光合特性,结果显示紫星凤梨(Guzmania‘Luna’,C3植物)、玉米(Zea mays L.,C4植物)的光合速率(Pn)日变化曲线均为双峰曲线,有明显的"光合午休",蝴蝶兰(Pha-laenopsis aphrodite Reichb×Phalaenopsis‘Doris’,CAM植物)的CO2吸收夜变化为双峰曲线;光合有效辐射(PAR)、气孔导度(Cond)、蒸腾速率(Trmmol)是影响玉米Pn大小的主要因素,Cond、Trmmol是影响蝴蝶兰CO2吸收的主因素,而Cond、RH是影响紫星凤梨Pn大小的主要原因,Trmmol、Cond调节光合作用,气孔因素不是影响叶片"光合午休"的主要因素;3种植物叶片中可溶性淀粉含量玉米最高(11.95μg·g-1FW),紫星凤梨和蝴蝶兰较低,分别为7.07μg·g-1FW、6.42μg·g-1FW,可溶性糖含量以蝴蝶兰最高(10.07mg·g-1DW),紫星凤梨的最低。玉米叶绿素含量及其Chla/Chlb的值均最大,较高的叶绿素Chla/Chlb有利于植物对于光能的吸收和利用。

Photosynthetic characteristics of three different photosynthetic plants were studied in the same environment. The results showed that the diurnal variation of net photosynthetic rate(Pn) of Guzmania‘Luna’ and Zea mays L. had two peaks. And they had obvious midday depression of photosynthesis. The photosynthesis variation of Phalaenopsis’s CO2 uptake rate had two peaks too. Photosynthetic active radiation(PAR),conductance to H2O (Cond)and transpiration rate(trmmol) were the main factors of photosynthetic rate in Phalaenopsis and Zea mays L..But conductance to H2O and relative humidity were the main factors of Guzmania ‘Luna’. Conductance to H2O and transpiration rate affected photosynthesis. The main factor leading to photosynthetic rate lowering was non-stomatal factors.The stomatal factors were not the main factor of midday depression of photosynthesis. The content of soluble sugar,starch and chlorophyll were different in three plant leaves. The content of soluble starch was the highest in Zea mays L. (11.95 μg·g-1 FW). And Guzmania ‘Luna’ and Phalaenopsis were lower,being 7.07 μg·g-1 FW and 6.42 μg·g-1 FW. Chlorophyll a/b was also find the highest in Zea mays L..The content of soluble sugar was the highest in Phalaenopsis (10.07 mg·g-1 DW),Guzmania‘Luna’ was the lowest. The content of chlorophyll and the rate of chlorophyll Chla/Chlb were the highest in Zea mays L,Higher rate of chlorophyll Chla/Chlb benefit the absorption of light.