水培对中国红豆杉(Taxus chinensis)根系结构及生理生化的影响

摘要

为了缓解红豆杉种质资源匮乏的现状和提高人工种植的红豆杉品质，试验运用水培技术，利用赤霉素（ GA3）处理诱导水培红豆杉生根，通过比较水培与土培中国红豆杉在根系结构、叶片色素含量、超氧化物歧化酶（SOD）活性、过氧化氢酶（CAT）活性、过氧化物酶（POD）、丙二醛（MDA）含量等部分指标的区别，揭示水培对红豆杉根系结构及生理生化的影响，探索从土培到水培转化过程中的变化规律。结果表明：400 mg／L GA3处理能显著促进水生根的形成；水培红豆杉洁白光滑，侧根少，无根毛，在显微结构上，细胞紧凑，缺少维管柱细胞，有发达的通气组织；水培红豆杉叶绿素含量低于土培组，但SOD、CAT、POD活性均高于土培组（ P＜0．01），MDA含量无显著区别，表明红豆杉从土培到水培转变过程中，部分形态及生理生化指标会发生改变来适应新环境，说明水培可以影响红豆杉的根系结构、色素含量以及部分抗氧化能力。实验为红豆杉的大规模无土栽培提供科学的理论依据。%In order to alleviate the current situation of Taxus chinensis germplasm resource scarcity and improve the quality of artificial planting Taxus chinensis, the gibberellic acid ( GA3 ) to treat the biennial yew Taxus chinensis was used to establish a inducing system of water root.Root structure, leaf pigment content and part enzyme activities , such as siperoxide dismutase(SOD), hydrogen peroxide (CAT), peroxidase(POD), malondialdehyde content(MDA), were measured in comparison of hydroponic and soil cultured yews to reveal the impact of hydroponic on Taxus chinensis root structure physiologically and biochemically and explore the changing rules from soil culture to hydroponic of Taxus chinensis.The optimal inducing concentration of GA 3 promoting yew rooting of water root was 400 mg/L.The hydroponic yew root structure was smoother and more white and compact than those in soil .Developed aerenchyma organi-zation and lack of vascular cylinder cell and root hair and less lateral root were observed in hydroponic group .The contents of pigment in hydroponic group were lower than that in soil cultured group .The activity of SOD , CAT and POD in hydroponic group was higher than that in soil cultured group ( P<0.01 ) , although the MDA content showed no significant change .Our studies suggest that part of the morphological and physiological and biochemical indexes were changed to adapt to low oxygen environment during the hydroponic process, showing hydroponic can influence of root structure , pigment contents and some of the capacity of antioxidant , providing scien-tific theory basis for large fields of soilless cultivation of Taxus chinensis.