硝酸盐水平对芹菜幼苗生理及生长特性的影响

以西芹‘文图拉’幼苗为试材,通过水培方式研究了不同浓度NO3-(0、1、5、10、15、50、100、150mmol·L-1)对芹菜植株生物量、养分含量、叶绿素、丙二醛(MDA)及两种渗透调节剂含量的影响。结果显示:(1)随着NO3-浓度的增加(1～50mmol·L-1),芹菜株高、生物产量、根冠比以及叶面积显著增加,植株对N、P、K养分的吸收和叶绿素明显提高,同时植株的MDA含量上升,POD和CAT的活性增强,可溶性糖和可溶性蛋白含量显著增加。(2)当NO3-浓度等于或大于100mmol·L-1时,芹菜的生物产量和叶绿素含量下降,植株对K、P养分的吸收降低,膜脂过氧化物MDA、可溶性糖和可溶性蛋白含量及SOD活性达到最高峰值,POD和CAT活性有所下降。研究表明,NO3-浓度为15mmol·L-1时最有利于芹菜植株的生长;NO3-浓度为100mmol·L-1时对植株生长产生了硝酸盐胁迫,导致膜脂过氧化伤害,但芹菜植株能通过调节抗氧化物酶活性及渗透调节剂的合成代谢抵御环境胁迫,从而表现出一定的硝酸盐耐受性。

Effects of Nitrate Level on the Physiological Characteristics and Growth of Apium graveolens Seedlings

A hydroponic culture experiment was conducted to study on the physiological characteristics and growth of Apium graveolens L.var.dulce DC.seedlings under the different NO3-concentration(0,1,5,10,15,50,100 and 150 mmol·L-1).The results showed that:(1)With NO3-concentration increased(1~50 mmol·L-1),the heights,biomass,shoot/root ratio and leaf area of the seedlings increased;the absorption of N,P,and K nutrients improved;the content of chlorophyll and the MDA increased;and the activities of POD and CAT increased.(2)When the NO3-concentration was equal to or higher than 100 mmol·L-1,the biomass and the content of chlorophyll decreased;the absorption of P,and K nutrients reduced;the MDA,soluble protein and sugar content,SOD activity appeared its highest peak;and the activities of POD and CAT decreased.We can concluded that the NO3-concentration of 15 mmol·L-1 favored the growth of celery;and the NO3-concentration of 100 mmol·L-1 caused the nitrate stress to the plant growth and resulted in injury to membrane lipid peroxidation,but the anti-oxidation enzyme and osmatic adjustment substance could adjust themselves to avoid nitrate stress harms,which led to some tolerant ability of Apium graveolens L.var.dulce DC to nitrate stress condition.