桃儿七光合生理特性的地理差异研究

Photosynthetic Characteristics of Sinopodophyllum hexandrum from Different Distribution Areas in China

对中国由南向北5个种源地桃儿七(Sinopodophyllum hexandrum)的光合生理生态特性进行了研究.结果表明:(1)北部宁夏六盘山地区植株的光饱和点(LSP)和光补偿点(LCP)最高,表观光量子效率(AQY)、瞬时光能利用效率(ILUE)和最大光合速率(Pmax)最低,光合能力最差;最南部云南纳帕海植株的LSP和LCP很低,但因其AQY和ILUE最高,故其Pmax最大,强光下的光合能力最高.(2)最南部云南纳帕海和最北部甘肃兴隆山个体的羧化效率(CE)最高,且CO2补偿点(CCP)较低,因此CO2利用率较高;而较南部四川刷经寺个体的CE最低,且CCP最高,故CO2利用效率最低.(3)各种源植株叶片的叶绿素总量及叶绿素a含量无显著差异,而不同地区个体的Chla/Chlb值差异显著,最北部甘肃兴隆山植株的Chla/Chlb值最大,而南部四川刷经寺的Chla/Chlb值最小.(4)各种源地植株的水分利用效率(WUE)和蒸腾速率(Tr)对光量子通量密度(PFD)与CO2浓度的响应过程也表现出显著的地理分异.总的来看,桃儿七是一种喜光但又较耐阴植物,但不同分布区桃儿七的光合生理生态特征已经出现了较显著的地理分化.

The photosynthetic characteristics of Sinopodophyllurn hexandrurn collected from five different distribution areas were studied by comparing photosynthesis processes and related parameters. The results indicated that （1）the highest light saturation point （LSP） and light compensation point （LCP） of individuals from Ningxia Liupanshan,as well as the lowest apparent quantum yield （AQY） and instantaneous light utilization efficiency （ILUE） resulted in the lowest photosynthetic ability. The photosynthetic ability of individuals from Yunnan Napahai was the highest because of the highest AQY and ILUE, （2）Due to higher carboxylation efficiency （CE） and lower CO2 compensation point （CCP） ,the CO2 utilization rate of individuals from Yunnan Napahai and Gansu Xinglongshan were higher,while that of Sichuan Shuajingsi was the lowest owing to the lowest CE and the highest CCP. （3）The total chlorophyll contents and the chlorophylla （Chi a） contents from all samples were not significantly different,merely the Chl a/Chl b value among five provenances were different obviously. The Chl a/Chl b value of individuals from Gansu Xinglongshan and Sichuan Shuajingsi were the highest and the lowest,respectivelv. （4）The response course of water use efficiency （WUE） and transpiration rate （Tr） to photon flux density （PFD） and CO2 concentration of S. , hexandrum from five distribution areas exhibited geographical differentiation distinctly. In general,S, hexandrum should be a light-preferring but shade-tolerant species, whereas their photosynthetic characteristics have come into being significant geographical differentiation.