高能碳离子束辐射黄芩幼苗的生物学效应

Biological Effects of High-Energy Carbon Ion Beam Irradiation on Seedlings of Scutellaria baicalensis

为探究高能重离子束辐射对黄芩幼苗生理特性及生长发育的影响,采用总能量为967 MeV的碳离子束辐射黄芩幼苗,测定了不同剂量辐射后的存活率、苗高、叶片数、分枝数、生物量、根冠比、抗氧化酶活性、光合作用特性及次生代谢产物的含量。结果显示,与对照组比较,黄芩幼苗的半致死剂量为32.82 Gy。5和10 Gy的重离子束辐射后黄芩的苗高、叶片数、分枝数和生物量均有增加,而30 Gy辐射均为降低。各处理组超氧化物歧化酶(Superoxide dismutase,SOD)和过氧化物酶(Peroxidase,POD)活性增加以减轻辐射造成的活性氧损伤。辐照后6周内,叶片中叶绿素含量随剂量呈下降趋势。辐照后第9周,5和10 Gy辐照提高了叶片的总叶绿素含量、净光合速率和气孔导度,10 Gy辐射促进了黄芩根中总黄酮和黄芩素的积累。研究发现,10 Gy的重离子束辐射促进了黄芩幼苗的生长,并且提高了其药用成分含量。本工作探究了重离子束辐射黄芩的当代生物学效应,为后续开展黄芩的辐射刺激效应及辐射育种研究提供了基础依据。

To explore the effects of high-energy heavy ion beams irradiation on the physiological and growth characteristics of Scutellaria baicalensis Georgi seedlings,different doses of carbon ion beam with total energy of 967 MeV were selected to irradiate seedlings to measure the survival rate,seedling height,number of leaves,number of branches,biomass,root-shoot ratio,antioxidant enzyme activity,photosynthetic characteristics and content of secondary metabolites.The results showed that the semi-lethal dose of seedlings was 32.82 Gy.The seedling height,number of leaves,number of branches,and biomass of Scutellaria baicalensis increased under 5 and 10 Gy,but decreased under 30 Gy compared with the control group.The activities of superoxide dismutase(SOD)and peroxidase(POD)in all treatment groups increased to reduce the damage of reactive oxygen species caused by irradiation.The content of chlorophyll in leaves decreased with the dose within 6 weeks after irradiation;the content of total chlorophyll,net photosynthetic rate and stomatal conductance of leaves increased under 5 and 10 Gy in 9 weeks after irradiation.In addition,the accumulation of total flavonoids and baicalein in the root were promoted under 10 Gy.These results indicated that 10 Gy heavy ion beams not only stimulated the growth,but also increased the content of medicinal ingredients in Scutellaria baicalensis.The study explored the contemporary biological effects of heavy ion beams radiation on Scutellaria baicalensis Georgi,which provides a basis for the follow-up research on irradiation stimulation effects and radiation breeding of Scutellaria baicalensis Georgi.