4种野生报春花光合作用特性的比较

Comparison of the Photosynthetic Characteristics in Four Wild Primula Species

采用LI-6400便携式光合作用系统分析了昆明露地栽培的4种野生报春花(3年生)光合作用特性。光补偿点以粉背灯台报春最高(28μmol·m-2·s-1),其余3种相近且较低(8～15μmol·m-2·s-1)。光饱和点以四季报春最低(80μmol·m-2·s-1),其光合速率也最低,两种灯台报春的光饱和点(500μmol·m-2·s-1)和光合速率均最高,灰岩报春居中。光合作用CO2补偿点灰岩报春、桔红灯台报春、粉背灯台报春和四季报春分别为54,64,69和80μmol·mol-1。5月份的光合速率和蒸腾速率日变化均呈单峰曲线,前者的峰值出现在10时左右,后者的峰值出现在13时左右;曲线高低体现出种间差异。

Plants of four wild Primula species were planted in the field at Kunming and the photosynthesis was tested with LI-6400 portable photosynthesis system for adding knowledge of photosynthesis to the wild Primula species. Species difference was found in light compensation point (LCP, μmol · m-2 · s-1 ) , light saturation point (LSP,μmol· m-2 · s-1) and CO2 compensation point (CCP, CO2μmol · mol-1) of photosynthesis. Primula pulverulenta Duthie had the highest LCP (28) , the other three species had lower LCP (8 - 15). P. obconica Hance had both low LSP (80) and photosynthetic rate (Pn) , and highest CCP (80). P. bulleyana Forr. and P. pulverulenta showed both the highest LSP (500) and Pn, and intermediate CCP (64 -69) , while P. forrestii Balf, f. had middle LSP and Pn, but the lowest CCP (54). The diurnal changes of Pn and transpiration rate (Tr) in May were one-peaked curves, reaching a maximum at about 10 and 13 o' clock for Pn and Tr, respectively. The species differences were exhibited by curve height of their diurnal courses.