PEG处理对臭椿种子萌发的影响

Effect of PEG on Seed Germination of Ailanthus altissima

采用0.0%(CK),2.5%,5.0%,7.5%,10%(w/v)几种浓度的聚乙二醇(PEG)对臭椿种子的萌发进行渗透胁迫处理,结果表明,随着PEG浓度的升高,臭椿种子的发芽率、发芽势、发芽速度、活力指数均呈下降趋势;发芽后幼苗的高生长、鲜重也呈下降趋势,而根长呈上升趋势;幼苗叶绿素含量、脯氨酸含量、超氧化物歧化酶(SOD)活性等变化差异较大,在PEG浓度大于5.00%时,脯氨酸含量、SOD活性显著增加,叶绿素含量显著减少.综合分析认为,臭椿具有一定的耐旱性,在实验室环境条件下,臭椿种子萌发及其幼苗可忍受 5.0%～7.5%的PEG渗透胁迫.

Through different PEG concentrations （0.0%, 2.5% ,5.0% ,7.5%,10%） treating the seed and seedling of Ailanthus altissima during their germination and growth period, this paper studied the effect of PEG treatment on the seed germination of tree of heaven. The result showed that with the increasing of PEG concentrations, the germination percentage, germination potential, seed vigor index, seedling height growth and fresh weight were all decreased gradually, but root growth was promoted, and the variations of proline content, chlorophyll content and SOD activity of the seedling leaf were significant. The proline content and SOD activity were greatly increased when the PEG concentration up to 5. 00% while the chlorophyll content was largely decreased. According to the result it could be concluded that A. altissima showed some drought resistance characteristics that could tolerant the osmotic stress of 5. 0% to 7. 5% PEG treatment under lab condition.