不同水氮配比对甘草生长、水分利用效率和类黄酮含量的影响

Effects of different ratios of water and nitrogen on growth,water use efficiency and flavonoid content of Glycyrrhiza uralensis

为研究不同水氮配比对甘草生长的影响,以乌拉尔甘草为研究对象,采用裂区试验设计,以4种灌水量为主区,4个氮肥水平为副区,研究水、氮因子及其组合对甘草净光合速率、叶绿素荧光参数、叶绿素SPAD值、地上部干物质积累量,水分利用效率及叶片类黄酮含量的影响。结果表明:灌溉对净光合速率、最大荧光、最大光化学效率、叶绿素SPAD值、地上部干物质积累量、水分利用效率及类黄酮含量影响极显著;施用氮肥对净光合速率、最大荧光、最大光化学效率、叶绿素SPAD值和类黄酮含量影响极显著,对初始荧光、地上部干物质积累量和水分利用效率影响显著;水氮交互作用对净光合速率影响极显著,对叶绿素SPAD值和水分利用效率影响显著。相比于W_(1)N_(1)(灌溉定额750 m^(3)·hm^(-2),不施氮),W_(4)N_(3)(灌溉定额3 000 m^(3)·hm^(-2),氮肥施量140 kg·hm^(-2))的净光合速率、最大荧光、最大光化学效率、叶绿素SPAD值、地上部干物质积累量和类黄酮含量分别提高了18.1%、29.9%、26.4%、17.7%、24.8%和32.1%,初始荧光降低了6.7%,表明灌溉定额3 000 m^(3)·hm^(-2),施氮量140 kg·hm^(-2)的处理有利于提高甘草的光合效率,增加叶绿素含量及干物质积累量,提高叶片类黄酮含量。相关性分析表明,净光合速率、最大荧光、最大光化学效率和叶绿素SPAD值均与甘草地上部干物质积累量及叶片类黄酮含量呈极显著正相关,与水分利用效率呈极显著负相关。

To research the influence of different ratio of water and nitrogen on growth of Glycyrrhiza uralensis,G.uralensis was selected as materials and splitplot experimental design was conducted with 4 kinds of irrigation amount in the main plots and 4 nitrogen level in the subplot.The effects of water,nitrogen and their combinations on net photosynthetic rate,chlorophyll fluorescence parameters,chlorophyll SPAD value,above-ground accumulation of dry matter,water use efficiency and flavonoid content in leaves of Glycyrrhiza were studied.The results showed that irrigation had extremely significant effects on net photosynthetic rate,maximum fluorescence,maximum photochemical efficiency,chlorophyll SPAD value,aboveground accumulation of dry matter,water use efficiency and flavonoid content.The application of nitrogen fertilizer had extremely significant effects on net photosynthetic rate,maximum fluorescence,maximum photochemical efficiency,chlorophyll SPAD value and flavonoid content,while had significant effects on initial fluorescence,above-ground accumulation of dry matter,and water use efficiency.The interaction of irrigation and nitrogen had extremely significant effects on net photosynthetic rate,while had significant effects on chlorophyll SPAD value and water use efficiency.Compared with W_(1)N_(1)(irrigation amount was 750 m^(3)·hm^(-2),zero nitrogen),net photosynthetic rate,maximum fluorescence,maximum photochemical efficiency,chlorophyll SPAD value,above-ground accumulation of dry matter,and flavonoid content of W4N3(irrigation amount was 3000 m^(3)·hm^(-2),nitrogen application was 140 kg·hm^(-2))increased by 18.1%,29.9%,26.4%,17.7%,24.8%and 32.1%,respectively,while initial fluorescence decreased by 6.7%.These indicateded that W_(4)N_(3) with irrigation amount of 3000 m^(3)·hm^(-2) and nitrogen fertilizer amount of 140 kg·hm^(-2)could improve the photosynthetic efficiency of G.uralensis,increase the content of chlorophyll and accumulation of dry matter,and raise the content of flavonoids in leaves.Correlation analysis showed that net photosynthetic rate,maximum fluorescence,maximum photochemical efficiency and chlorophyll SPAD value were significantly positively correlated with above-ground accumulation of dry matter and flavonoid content in leaves,while significantly negatively correlated with water use efficiency.