作 者 ：杨 艺1,2,常 丹2,王 艳1,2*,张雪妍1,李付广1,张富春2

期 刊 ：西北植物学报 2015年 2期 页码：302~308

关键词：棉花；干旱胁迫；茉莉酸甲酯；茉莉酸；种子萌发；种苗生理特性；

Keywords:Gossypium hirsutum, drought stress, jasmonic aicd, methyl jasmonat, seed germination, physiological characteristics of seedling,

摘 要 ：以新疆棉花主栽品种‘新陆早17’为材料,采用PEG模拟水分胁迫的方法,探讨不同浓度(0.025、0.25、2.5、25、250 μmol/L)外源激素茉莉酸(JA)和茉莉酸甲酯(MeJA) 预处理对23% PEG-6000模拟干旱胁迫下棉花种子萌发及种苗生长、水分含量、根系活力、脯氨酸和氧化损伤的影响,为JA和MeJA在棉花生产中的合理使用提供依据。结果显示:(1)JA和MeJA预处理能够显著缓解23% PEG-6000对棉花种子的干旱胁迫伤害,且2.5 μmol/L MeJA预处理使干旱胁迫下棉花种子的发芽率和发芽势达到最高(70.0%、63.3%),比23% PEG-600干旱胁迫对照分别提高了49.99%、72.70%;0.025 μmol/L JA预处理使干旱胁迫下棉花种子的发芽指数和活力指数达到最高(27.3、203.1),比对照分别提高了68.14%、190.29%;2.5 μmol/L JA预处理使干旱胁迫下根系活力达到最高,比对照提高266.68%。(2)两种激素预处理均能够使干旱胁迫下棉花种苗的脯氨酸含量显著上升,丙二醛含量显著降低。研究表明,适宜浓度外源JA和MeJA能够显著缓解干旱胁迫对棉花种子伤害,促进棉花种子萌发、种苗生长,增强根系代谢和减轻种苗的氧化损伤,从而增强其耐旱能力;MeJA预处理效果要好于JA预处理,且干旱条件下棉花种子萌发及种苗生长的最适MeJA预处理浓度为2.5 μmol/L,而0.025 μmol/L JA则为棉花种子萌发的最适作用浓度,0.25和2.5 μmol/L则分别为种苗生长过程中促进作用最明显的浓度。

Abstract:PEG-6000 was used to imitate the drought stress,and under 23% PEG-6000 the effects of exogenous jasmonic acid (JA) and methyl jasmonic acid (MeJA) pretreatment at five concentrations of 0.025,0.25,2.5,25,250 μmol/L were measured on seed germination,seedling growth,water content,root activity,proline content,and the effects of oxidative damage in cotton cultivar ‘Xinluzao 17’.The results indicated that:(1)The seed germination rate,germination potentiality,germination index,and vigor index were all improved with pretreatment by a certain concentration of JA and MeJA.The seed germination rate and germination potentiality were significantly increased by 49.99% and 72.70% with 2.5 μmol/L MeJA pretreatment.While seed germination index and vigor index by using 0.025 μmol/L JA pretreatment was increased by 68.14% and 190.29% in compared with the control group.The root activity reached the maxima by using 2.5 μmol/L JA and its level was higher 266.68% than the control.(2)Both JA and MeJA pretreatment were able to significantly increased proline content and reduced MDA content under drought stress in the seedling.The results demonstrated that JA and MeJA in a certain concentration could effectively mitigate inhibitory effect under drought stress and improve the cotton seed germination and seedling growth.In general,the ability for alleviation to drought stress by MeJA pretreatment was better than JA.0.025 μmol/L JA was the optimum pretreatment concentration for seed germination, while 0.25 and 2.5 μmol/L JA were the optimum pretreatment concentration for seedling growth under drought stress,and for MeJA,the optimum pretreatment concentration was 2.5 μmol/L for both seed germination and seedling growth,which provided the scientific basis for agricultural production.