几种银莲花光合特性的初步分析

采用LI6400便携式光合仪分析昆明室外栽培的几种野生银莲花光合作用特性。净光合速率(Pn)和蒸腾速率(Tr)日变化均呈单峰曲线,前者的峰值出现在10～11点,后者的峰值出现在13点前后。在光强0～2000μmol·m2·s1条件下,Pn呈S曲线,光合补偿点为60～80μmol·m2·s1,饱和点为800μmol·m2·s1左右,但光强继续增加到1800μmol·m2·s1,Pn仍有少许提高;Tr随PAR的增加而缓慢地增加。在环境CO2浓度为0～350μmol·mol1条件下,Pn直线上升,草玉梅、秋牡丹和野棉花的光合CO2补偿点均为50μmol·mol1左右;Tr在环境CO2浓度25～350μmol·mol1范围内几乎呈水平线。野生银莲花的Pn和Tr表现较明显的种间差异。

Preliminary study on the photosynthetic characteristics of some Anemone species

The photosynthesis of several field-grown Anemone species was investigated by using LI-6400 portable photosynthesis system in Kunming,Yunnan Province,China. The diurnal pattern of net photosynthetic rate(Pn)and transpiration rate(Tr)appeared as single peak curves. The peak values appeared at 10∶00～11∶00 and about 13∶00 for Pn and Tr,respectively. The change pattern of Pn looked like an S curve under 0～2 000 μmol·m~-2·s~-1 of photosynthesis active radiation(PAR). The light compensation point and light saturation point of photosynthesis were at PAR 60～80 μmol·m~-2·s~-1 and at about PAR 800 μmol·m~-2·s~-1. But Pn still increased slightly with the increase of PAR from 800 to 1 800 μmol·m~-2·s~-1. Tr only slightly increased as PAR increasing from 0～2 000 μmol·m~-2·s~-1. Under 0～350 μmol·mol~-1 of CO2 concentration,Pn increased linearly,showing a CO2 compensation point at 50 μmol·mol~-1 for A. rivularis,A.hupehensisvar.japonicaand A.vitifolia. Tr change was a horizontal line under 25～350 μmol·mol~-1 of CO2 concentration. The tested Anemonespecies showed difference between their Pn and Tr.