赤霉素对干旱胁迫下高羊茅萌发及幼苗生长的缓解效应  

Effects of gibberellin on seed germination and seedling growth of tall fescue under drought stress

作　　者：陈志飞[1] 宋书红[1] 张晓娜[1] 张莹[1] 李欣悦[1] 杨云贵[1] 

机构地区：[1]西北农林科技大学动物科技学院,陕西杨凌712100

出　　处：《草业学报》2016年第6期51-61,共11页Acta Prataculturae Sinica

基　　金：国家牧草产业技术体系"优质牧草产品标准化生产关键技术"(CASR-35-01A);国家燕麦产业技术体系"燕麦加工利用"(CARS-08-D1)资助

摘　　要：为研究PEG胁迫下赤霉素浸种对高羊茅种子萌发的影响,试验选用5个赤霉素浸种处理：0,100,200,300,400mg/L,浸种后分别在0%,5%,10%,15%,20%5个浓度PEG胁迫下进行萌发试验,对浸种后种子的丙二醛,电导率和萌发及幼苗生长情况进行测定。结果表明：0和100 mg/L赤霉素浸种后种子的电导率显著高于（P≤0.05）其他3个浓度,丙二醛含量显著低于（P≤0.05）其他3个浓度。随着PEG浓度的升高,对种子的萌发和幼苗的抑制作用逐渐增强,当PEG浓度高于15%时,种子发芽率和根,芽长有明显下降。在5%和10%PEG胁迫时,100mg/L赤霉素与0mg/L浸种相比发芽势提高了47.06%、37.33%,发芽率提高了19.46%、16.95%。在5%,10%PEG胁迫时,200mg/L赤霉素与0mg/L浸种相比根长分别提高了53.26%、30.12%,芽长提高了79.87%、50.75%,随着PEG胁迫增大,赤霉素缓解PEG胁迫抑制根芽生长的作用逐渐减弱。另外,PEG胁迫对芽长的抑制作用比根长更强,而且经赤霉素浸种后幼苗的根冠比明显变小。综上所述,促进高羊茅种子萌发,幼苗生长和缓解干旱胁迫最适宜的赤霉素浓度为100~200mg/L。This study investigated the effects of gibberellin concentrations on seed germination and seedling growth of tall fescue （Festuca arundinacea ）under drought stress.The seed germination experiment was con-ducted at 5 polyethylene glycol （PEG）levels （0%,5%,10%,15% and 20%）after soaking seeds in 5 gibber-ellin concentrations （0,100,200,300 and 400 mg/L）.The malondialdehyde concentration （MDA）and electri-cal conductivity of seeds were determined before germination,then the seedling growth,seed germination rate and potential were measured during germination.The electrical conductivities of seeds soaked in 0 and 100 mg/L gibberellin were significantly （P ≤0.05）higher than those of seeds soaked at the other three gibberellin concentrations,and MDA concentrations of seeds soaked with 0 and 100 mg/L gibberellin solution were signifi-cantly lower （P ≤0.05）than those of seeds soaked at the three higher gibberellin concentrations.Compared to seeds soaked in pure water,the 5% and 10% PEG treatments had,respectively,47.06% and 37.33% greater germination potential,and 19.46% and 16.95% higher germination rate.However,the germination rate,and root and bud length were obviously decreased when the PEG concentration was 15% or higher.After soaking in 200 mg/L gibberellin solution,root length was increased 53.26%,30.12% （compared with soaking in pure water）and the corresponding increases in bud length were 79.87% and 50.75% at 5% and 10% PEG solu-tions.The effect of gibberellin decreased with increase in PEG level.The inhibition of PEG stress on bud length was stronger than on root length,but the root length：bud length ratio was obviously decreased water after gibberellin treatment,compared to that of seeds soaked in pure.In summary,the optimum gibberellin concen-tration for enhancing the seed germination and seedling growth of tall fescue under drought stress was 100-200 mg/L.

关 键 词：高羊茅 赤霉素 聚乙二醇(PEG) 种子萌发 缓解效应 

分 类 号：S688.4[农业科学—观赏园艺]