野生与栽培黄花蒿净光合速率对光强和CO2浓度的响应

Responses of Net Photosynthetic Rate to Light Intensity and CO2 Concentration in Leaves of Wild and Cultivar Artemisia annua

摘要:

比较了相同种源的野生和栽培黄花蒿(Artemisia annua L.)净光合速率对光强和CO2浓度的响应特性。结果表明，野生和栽培黄花蒿的光饱和点（LSP）分别为1 183和1 564 μmol m^-2s^-1，光补偿点（LCP）为17和18 μmol m^-2s^-1，最大净光合速率（Pmax）为18.78和22.38 μmol m^-2s^-1，表观量子效率（AQY）为0.08和0.075 μmol m^-2s^-1，表明黄花蒿的光合能力强，能够利用很高的光强，且对弱光的适应性也较强。栽培黄花蒿的Pmax、LSP和最大羧化速率(Vcmax)显著高于野生黄花蒿，两者的LCP、不包括光下呼吸的CO2补偿点、AQY、光下呼吸速率和最大电子传递速率(Jmax)差异不显著。强光下栽培黄花蒿主要通过提高Vcmax和Jmax等来增强光合能力，强的光合能力有利于黄花蒿的生长，因此在人工栽培黄花蒿的过程中应选择阳光充足的开阔生境。

Abstract:

The responses of net photosynthetic rate (Pn) to light intensity and the CO2 concentration in leaves of homologous wild and cultivar Artemisia annua were studied. The maximum net photosynthetic rate (Pmax) was 18.78 μmol m^-2s^-1 for the wild-type and 22.38 μmol m-2s-1 for the cultivar. The light saturation point (LSP) was 1 183 μmol m^-2s^-1for the wild-type and 1 564 μmol m^-2s^-1 for the cultivar. The light compensation point (LCP) was 17 μmol m-^-2s^-1for the wild-type and 18 μmol m^-2s^-1 for the cultivar. The apparent quantum yield (AQY) was 0.08μmol m^-2s^-1 for the wild-type and 0.075 μmol m^-2s^-1 for the cultivar. Those data indicated that A. annua could utilize high light irradiance and perfectly acclimate to low light condition. Pmax, LSP and maximum carboxylation rate of Rubisco (Vcmax) were significantly higher in cultivar A. annua than in the wild-type. LCP, AQY, maximum rate of electron transport (Jmax), rate of non-photorespiratory CO2 evolution in the light (Rd) and CO2 compensation point in absence of respiration in the light (Г*) were not significant difference between the wild-type and cultivar. High light irradiance enhanced A annua in photosynthetic capacity by increasing Vcmax and Jmax and therefore A annua should be cultivated in an open and sun-filled habitat.