钾营养对花期干旱胁迫芝麻生长及叶片氮代谢的影响  

Effects of Potassium on Growth and Leaf Nitrogen Metabolism of Sesame under Drought Stress at Flowering Stage

作　　者：张梓然 郑德益 涂子豪 方圣 ZHANG Ziran;ZHENG Deyi;TU Zihao;FANG Sheng(College of Agronomy,Jiangxi Agricultural University/Jiangxi Province Key Laboratory of Crop Physiology,Ecology and Genetics Breeding,Ministry of Education,Nanchang,Jiangxi 330045;Agriculture,Forestry and Water Science Research Center of Shangrao,Shangrao,Jiangxi 334000)

机构地区：[1]江西农业大学农学院/江西省作物生理生态与遗传育种教育部重点实验室,江西南昌330045 [2]上饶市农林水科学研究中心/上饶市农业科学研究院,江西上饶334000

出　　处：《核农学报》2024年第9期1782-1789,共8页Journal of Nuclear Agricultural Sciences

基　　金：国家自然科学基金(32060438)。

摘　　要：为探究花期干旱胁迫下不同钾肥水平对芝麻(Sesamum indicum L.)生长和叶片氮代谢的影响,以及芝麻响应干旱胁迫的生理机制,以赣芝7号为试验材料,采用盆栽控水试验方法,设置3个钾肥水平(0、60、120 kg·hm^(-2);K_(2)O)和2个土壤水分处理(75%±5%和45%±5%田间持水量),对比不同钾肥水平下芝麻生长、氨基酸、可溶性蛋白含量、氮代谢酶活性等指标的差异。结果表明,干旱胁迫严重抑制芝麻生长,与正常灌水相比,干旱处理芝麻叶片相对含水量、株高、比叶重和叶绿素值分别平均下降8.2个百分点、23.5%、8.1%和6.6%。干旱导致芝麻叶片的氮代谢能力减弱,与正常灌水相比,干旱处理芝麻叶片的氮、钾、可溶性蛋白(SP)和氨基酸(AA)含量分别平均提高5.4%、10.6%、21.1%和52.7%,硝酸还原酶(NR)和谷氨酸合成酶(GOGAT)活性分别平均下降11.3%和16.6%。干旱胁迫下,与不施钾相比,施钾使芝麻叶片相对含水量、株高、比叶重、叶绿素值、钾、氮含量分别提高3.3~7.2个百分点、20.9%~39.0%、3.2%~5.5%、1.0%~4.5%、14.8%~19.6%、2.0%~5.4%;硝酸还原酶和谷氨酸合成酶活性分别提高8.7%~9.5%和15.1%~20.0%。相关性分析表明,干旱胁迫下,叶片钾含量与氮、SP、FAA含量及NR、GOGAT活性呈显著或极显著正相关(R^(2)=0.69~0.95)。综上所述,施钾可缓解干旱胁迫对芝麻造成的不利影响,提高叶片钾、氮含量及硝酸还原酶和谷氨酸合成酶活性;施钾主要通过调控渗透调节、蛋白质合成及氮代谢等途径来提高芝麻的耐旱性。本研究结果为芝麻抗旱栽培提供了科学依据。To explore the effects of different potassium(K)fertilizer levels on the growth and leaf nitrogen(N)metabolism of sesame(Sesamum indicum L.),and the physiological mechanism in response to drought stress(DS)at flowering stage,sesame cultivar Ganzhi No.7 was selected and a pot experiment was carried out.Three K levels(0,60,120 kg·hm^(-2)K_(2)O)and two soil water treatments(75%±5%and 45%±5%of field capacity,respectively)were set to analyze the growth,amino acids(AA),soluble proteins(SP)contents and N metabolic enzyme activities of sesame.The results showed that drought seriously inhibited the growth of sesame.Compared to well-watered plants,the relative water content,plant height,specific leaf weight and SPAD value of sesame in drought conditions were averagely decreased by 8.2 percentage points,23.5%,8.1%and 6.6%,respectively.Drought reduced the nitrogen metabolism ability in sesame leaves.Compared to normal watering,drought averagely increased the N,K,SP and FAA content of sesame leaves by 5.4%,10.6%,21.1%and 52.7%,respectively.Concurrently,the activities of nitrate reductase(NR)and glutamic acid synthase(GOGAT)were averagely decreased by 11.3%and 16.6%,respectively.Under drought conditions,compared with no K fertilizer,the relative water content,plant height,specific leaf weight,SPAD value,K and N content of sesame leaves were increased by 3.3-7.2 percentage points,20.9%-39.0%,3.2%-5.5%,1.0%-4.5%,14.8%-19.6%and 2.0%-5.4%,and the activities of NR and GOGAT were increased by 8.7%-9.5%and 15.1%-20.0%,respectively.Correlation analysis showed that leaf K content was significantly or extremely significantly positive correlated with N content,SP,FAA,NR and GOGAT(R^(2)=0.69-0.95)under drought stress.In conclusion,K application could effectively alleviate the adverse effects of drought stress on sesame,and increase K,N and the activities of NR and GOGAT in leaves.Applying potassium mainly improves sesame’s drought tolerance through regulating the osmotic adjustment,protein synthesis,and promoting nitrogen metabolism.

关 键 词：芝麻 干旱胁迫 钾肥 氮代谢 

分 类 号：S565.3[农业科学—作物学]