Abstract: To investigate the effects of drought and salt stresses on seed germination and seedling growth of pink muhly grass （Muhlenbergia capillaris）， the seeds of pink muhly grass ‘Fendai’ were exposed to different concentrations of PEG-6000 and NaCl， respectively. Responses of pink muhly grass to different concentrations of PEG-6000 and NaCl were analyzed， including seed germination rate， germination percentage and germination index， plumule and radicle length， plant height， tiller number， fresh weight， root/shoot ratio， total root length， root surface area， average root diameter， root volume， leaf relative water content， electrolyte leakage and chlorophyll content. The results showed that the germination rate， germination percentage and germination index， plumule and radicle length all decreased with the increase of PEG-6000 and NaCl concentrations. Based on the death rate under different solution concentrations， the semi-lethal concentrations of PEG-6000 and NaCl for pink muhly grass seeds were 13.25% and 0.65%， respectively. Seedlings treated with 14 days of PEG-6000 （15%， 20%， 25%， and 30%） and 21 days of NaCl （0.8%， 1.2%， and 1.6%） decreased plant height， root length， tiller number， fresh weight， total root length， root surface area， root volume， average root diameter， leaf relative water content， and chlorophyll content compared to non-stressed control， while root/shoot ratio and electrolyte leakage were higher than control. The results of the present study could provide a theoretical basis and technical support for cultivation and application for pink muhly grass.

Key words: Pink muhly grass, Drought stress, Salt stress, Seed germination, Seedling growth

摘要： 为阐明干旱和盐胁迫对粉黛乱子草（Muhlenbergia capillaris）种子萌发及幼苗生长的影响，本研究以粉黛乱子草品种‘粉黛’为试验材料，采用不同浓度聚乙二醇（Polyethylene Glycol，PEG-6000）及NaCl分别模拟干旱和盐胁迫处理，测定粉黛乱子草种子萌发指标、幼苗形态指标和生理指标，以确定其在干旱及盐胁迫条件下的种子萌发及幼苗生长阈值。结果表明，随着胁迫程度的增加，干旱和盐胁迫抑制粉黛乱子草种子萌发和幼苗生长的作用更加显著。PEG-6000处理粉黛乱子草种子的半致死浓度为13.25%，NaCl处理粉黛乱子草种子的半致死浓度为0.65%。经14天PEG-6000处理（15%，20%，25%，30%）和21天NaCl处理（0.8%，1.2%，1.6%）后，幼苗株高、根长、分蘖数、总鲜重、根系总长、根表面积、根体积、根平均直径以及叶片相对含水量、叶绿素含量均低于未加处理的幼苗，根冠比、电解质渗透率高于对照。本研究可为粉黛乱子草的推广应用提供一定的理论参考。

关键词: 粉黛乱子草, 干旱胁迫, 盐胁迫, 种子萌发, 幼苗生长