短期缺氮对西藏荨麻幼苗生长发育及生理特性的影响

Effects of Short-Term Nitrogen Deficiency on the Growth,Development and Physiological Characteristics of Urtica tibetica Seedlings

荨麻是喜氮和高蛋白植物,为探究短期缺氮对西藏荨麻(Urtica tibetica W.T.Wang)幼苗生长和生理特性的影响,试验采用水培法培育荨麻幼苗,设置缺氮处理(LN)和对照(CK),每7 d采集植株根茎叶测量相关指标。结果表明:缺氮显著降低荨麻的叶绿素a、叶绿素b与叶绿素总含量;缺氮显著降低荨麻超氧化物歧化酶(Superoxide dismutase,SOD)和过氧化氢酶(Catalase,CAT)活性;缺氮胁迫下,西藏荨麻的丙二醛(Malondialdehyde,MDA)、游离脯氨酸(Free proline,Pro)、可溶性糖(Soluble sugar,SS)、过氧化氢(Hydrogen peroxide,H_(2)O_(2))含量显著增加;缺氮胁迫下,西藏荨麻生长缓慢,地上部鲜重、总生物量显著低于CK,而株高、根长、地下部鲜重等指标无显著性差异。短期缺氮影响了西藏荨麻的活性氧系统及渗透调节物质,对地上部生物量、总生物量产生了显著影响,该试验为野生西藏荨麻人工栽培提供科学依据。

Stinging nettles are nitrophilous and high protein plant.To explore the effects of short-term nitrogen deficiency on the growth and physiological characteristics of Urtica tibetica W.T.Wang seedlings,this experiment used hydroponics to grow U.tibetica seedlings,setting up a nitrogen-deficient treatment group(LN)and a control group(CK).The roots,stems,and leaves of the plants were collected every 7 days to measure the relevant indexes.The results showed that:1)Nitrogen deficiency significantly decreased the levels of chlorophyll a,chlorophyll b,and total chlorophyll in U.Tibetica.2)Nitrogen deficiency significantly deceased the activities of superoxide dismutase(SOD)and catalase(CAT)in roots,stems and leaves of U.tibetica.3)The contents of malondialdehyde(MDA),free proline(Pro),soluble sugars(SS),hydrogen peroxide(H_(2)O_(2))in the roots,stems and leaves of U.tibetica were significantly increased under nitrogen deficiency stress.4)Under nitrogen deficiency stress,U.tibetica grew slowly,and its above ground fresh weight and total biomass were significantly lower than that of CK,while plant height,root length,underground fresh weight and other indicators were not significantly different from CK.Short term nitrogen deficiency affected the ROS system and osmotic regulatory substances of U.tibetica,and significantly affected the aboveground biomass and total biomass.This experiment provided scientific basis for the artificial cultivation of wild U.tibetica.