阳光紫外辐射对羊栖菜人工幼苗生长和光合电子传递速率的影响

Effects of solar UVR on the growth and photosynthetic electron transfer rate in artificially raised young seedlings of Hizikia fusiformis

为探讨经济褐藻羊栖菜人工幼苗对阳光紫外辐射变化的响应,在全波段阳光辐射省(PAB,280～700nm)、去除UV-B辐射(PA,320～700nm)和光合有效辐射PAR(P,400～700nm)三种辐射处理及不同辐射水平下培养羊栖菜幼苗,并测定了其生长与光合作用的变化。结果表明,无论在紫外辐射(UVR)存在情况下(PA,PAB)还是滤除UVR(PAR)时,高辐射水平条件下(55%),羊栖菜幼苗都具有较高的生长速率,而低辐射水平下羊栖菜的生长速率较低。在不同辐射处理之间,随着辐射水平的增高,UVR的抑制效应逐渐突显。UVR降低羊栖菜幼苗的光合电子传递速率。

Effects of solar ultraviolet radiation （UVR） on the growth and photosynthesis of artificially raised young seedlings of Hizikia fusiformis were investigated while exposed to full spectrum solar radiation （PAB, 280-700 nm）, solar radiation depleted of UV-B （PA, 320-700 nm） and solar radiation deprived of total UVR （P, 400-700 nm） in order to understand its responses to changes in solar UVR. It was found that the young seedlings showed higher relative growth rate at 55% of solar irradiance level, regardless of the treatments with UVR （PA, PAB） or without UVR （PAR）. Lower solar irradiance level resulted in low relative growth rate. Among the different treatments, the inhibitory effects on growth were increased with the enhancement of solar irradiance level. In addition, photosynthetic electron transfer rate of young seedlings was significantly suppressed by UVR.