遮阴对浙江三叶青生理生化及总黄酮的影响

为探究抗癌药物浙江三叶青在不同遮阴处理下其有效成分总黄酮含量及生理生化响应,该研究设置5个光照梯度(全光照CK、遮阴30%、50%、70%、90%),以三叶青二年生扦插苗为材料,处理6个月后,测定三叶青在不同遮阴梯度条件下的生长指标、生化指标以及不同部位(叶片和块根)的总黄酮含量。结果表明:遮阴70%的处理中植株长势最佳,随着光照强度的减弱,三叶青生物量呈现先增高后降低趋势;比叶重呈降低趋势;叶片中的可溶性蛋白(SP)、游离脯氨酸(FP)和超氧化物歧化酶(SOD)含量均在全光照下最高,遮阴70%时最低,分别比全光照降低了33.36%、17.22%、46.88%,表现出光胁迫特点;总黄酮含量为叶片块根,且均以遮阴70%下含量最高,从整体来看,总黄酮含量随着遮阴度的增大而呈现先增加后降低的趋势。这表明光照强度是影响浙江三叶青生长及有效成分积累的重要因素,且高光强在一定程度上抑制三叶青植株的生长,适当遮阴对三叶青植株的生长起促进作用,但块根和叶片中的总黄酮含量对光强的响应却不同,这为今后科学栽培种植及合理有效开发三叶青提供了科学依据。

Effects of different shading treatments on physiology, biochemistry and total flavonoids of Tetrastigma hemsleyanum in Zhejiang Province

Tetrastigma hemsleyanum is a kind of medicinal herbs, in which total flavonoids have anti-cancer effects. In recent years, with the increasing medical demand, it is imperative to explore the economic and biomimetic cultivation under the trees. The purpose of this study was to investigate total flavonoids contents, physiological and biochemical characteristics of T. hemsleyanum in Zhejiang Province responsed to different light intensities. Biennial cuttings were used as experimental materials and five light gradients(full light, shade 30%, 50%, 70% and 90%)were set up. After six months'' treatment, we determined the growth parameters(growth, biomass), biochemical parameters soluble protein(SP), free proline(FP), superoxide dismutase(SOD)] and contents of total flavonoids in different parts(leaves and rhizomes). The results showed that total length of the stems, maximum length and width of leaves, weight of single rhizomes increased first and then decreased with the decrease of light intensity; specific leaf weights decreased overall. Contents of SP, FP and SOD in leaves were the highest with full light conditions, the lowest with 70% shading(lower than total light was 33.36%, 17.22%, 46.88%). It showed that excessive high light and low light both affected photosynthesis and accumulation of active ingredients. Total flavonoid contents in leaves were higher than those in rhizomes, and the highest values of leaves(6.16 mg·g^-1)and rhizomes(2.21 mg·g^-1)were treated with 70% shading. In general, T. hemsleyanum grew best and suffered lowest stress in 70% shading treatments. The study indicates that light intensity is an important factor affecting the growth and accumulation of active constituents in T. hemsleyanum of Zhejiang Province, and high light intensity inhibits the growth of T. hemsleyanum to a certain extent, and appropriate shading promotes the growth. The total flavonoid content in the leaves responded differently to light intensity, which provided a scientific reference for scientific cultivation and rational development of T. hemsleyanum in the future.