干旱胁迫对5个海岛树种生长及生理特性的影响

摘要

To compare the drought-resistance of five island tree species,namely,Ilex integra,Machilus thunbergii,Cinnamomum japonicum var.chenii,Eurya emarginata,and Eurya japonica,an experiment was conducted using tree seedlings with different soil drought stress levels.Plant physiological responses to the drought stress were measured.Results showed that the root and shoot biomass decreased as drought increased,but the root-to-shoot ratios (R/S) increased first and then decreased.In addition,chlorophyll content (Chl) decreased as drought stress increased.With severe drought stress,the survival rate was C.japonicum var.chenii ＞ I.integra ＞ M.thunbergii =E.emarginata ＞ E.japonica.A subordinate function used to rank drought-resistance showed:C.japonicum var.chenii ＞ I.integra ＞ M.thunbergii ＞ E.japonica ＞E.emarginata.%为了解全缘冬青Ilex integra,红楠Machilus thunbergii,普陀樟Cinnmomum japonicum va.chenii,滨柃Eurya emarginata,柃木Eurya japonica等5个海岛树种的抗旱性,利用盆栽控水方式对5个海岛树种进行干旱胁迫试验,测定相关的生理指标,比较了5个树种之间抗旱能力的大小.结果表明:各树种的地上部分和地下部分生物量随着胁迫程度的增加而持续下降,而根茎比呈现出先降后升的变化趋势；5个树种的脯氨酸和相对电导率随干旱程度的加剧而呈上升趋势,叶绿素则随干旱程度的加深而明显下降.在重度胁迫下,5个树种的存活率大小依次为普陀樟＞全缘冬青＞红楠=滨柃＞柃木.通过隶属函数法分析得出5个树种在中度干旱和重度干旱条件下的抗旱性顺序为普陀樟＞全缘冬青＞红楠＞柃木＞滨柃.