干旱胁迫对山桐子种子萌发及幼苗生理特性的影响

Effects of Drought Stress on Seed Germination and Seedling Physiological Characteristics of Idesia polycarpa

以‘鄂选1号’、‘鄂选2号’及‘川桐32号’3个山桐子(Idesia polycarpa)品种为试验材料,采用聚乙二醇6000(PEG-6000,简称PEG)模拟干旱胁迫(0%PEG、10%PEG、15%PEG、20%PEG和25%PEG)的方法,通过对种子萌发期的发芽率、发芽指数、活力指数、胚芽和胚根的长度、幼苗生长量、幼苗根系活力、幼苗根系呼吸速率等指标进行测定,探讨干旱胁迫对山桐子种子萌发及幼苗生长的影响,了解不同品种山桐子抗旱性特征。结果表明,随着PEG浓度的提高,各品种山桐子的种子萌发参数均明显下降,同时籽苗胚根、胚芽生长和籽苗鲜重均受到明显影响。在连续的PEG干旱胁迫下,山桐子幼苗根系活力和呼吸速率反映极为敏感,各浓度PEG处理中均下降明显。当PEG浓度提高到25%时,种子萌发籽苗胚轴无法生长,盆栽幼苗干旱处理到第7天时,部分枯萎焉死。

To study effects of drought stress on seed germination and seedling growth of Idesia polycarpaby using the method of simulating drought stress(0%Polyethylene Glycol(PEG),10%PEG,15%PEG,20%PEG and 25%PEG),‘Exuan 1',‘Exuan 2' and‘Chuantong 32'were used as materials,and the germination rate,germination index,vigor index,germ length,radicle length,seedling growth,seedling root vigor,root respiration rate were measured.The results showed that the parameters of seed germination decreased with the increasing concentration of PEG,and the growth of germ and radicle were significantly affected.Under continuous drought stress of PEG,the root activity and respiration rate of Idesia polycarpaseedlings were sensitive,and they decreased obviously in each concentration of PEG treatment.When the PEG concentration increased to 25%,the seedling hypocotyl could not grow,and some withered seedings of potted seedlings were dead after treated 7 d.