几种野生银莲花生殖生长期的光合作用特性初探

Photosynthetic Characteristics of Some Anemone Species at Reproductive Growth Stage

采用LI-6400便携式光合仪对室外栽培的几种野生银莲花光合作用特性进行了研究.结果表明,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10:00～11:00时,后者的峰值出现在13:00时前后.在光强0～2000μmol·m-2·s-1条件下,Pn呈S曲线,光补偿点为60～80μmol·m-2·s-1,光饱和点为800μmol·m-2·s-1左右,但光强继续增加到1800μmol·m-2·s-1,Pn仍有少许提高;Tr随PAR的增加而缓慢增加.在环境CO2浓度为0～350μmol·mol-1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·mol-1左右;Tr在环境CO2浓度25～350μmol·mol-1范围内几乎呈水平线.野生银莲花的Pn和Tr表现出较明显的种间差异.

The photosynthesis of several field-grown Anemone species was investigated with LI-6400 portable photosynthesis system in Kunming, Yunnan Province, P.R. China. The daily patterns of net photosynthetic rate (Pn) and transpiration rate (Tr) appeared as single-peak curves. The peak values appeared in Pn and Tr at 10:00～11:00 and about 13:00, respectively. The change pattern of Pn looked like an 'S-shape' curve at 0～2 000 μmol·m^(-2)·s^(-1) of photosynthesis active radiation(PAR). The light compensation point and light saturation point of photosynthesis were PAR 60～80 μmol·m^(-2)·s^(-1) and about PAR 800 μmol·m^(-2)·s^(-1),respectively. 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 increased from 0 to 2 000 μmol·m^(-2)·s^(-1). Within 0～350 μmol·mol^(-1) of CO_2 concentration, Pn increased linearly, showing CO_2 compensation point at 50 μmol·mol^(-1) for A. rivularis, A. hupehensis var. japonica and A. vitifolia. Tr change was a horizontal line within 25～350 μmol·mol^(-1) of CO_2 concentration. The tested Anemone species showed difference in their Pn and Tr.