淹水深度对互叶白千层幼苗气体交换、叶绿素荧光和生长的影响

实验设置对照、浅淹(水位高出土壤表面5cm)和深淹(水位高出土壤表面20cm)3种处理,研究了淹水深度对互叶白千层幼苗的气体交换、叶绿素荧光和生长状况的影响。研究结果表明,随着淹水深度的增加,互叶白千层受到的胁迫程度有所增强。经过270d的淹水处理,浅淹组和深淹组的株高和生物量有所下降,分别为对照的90.86%、64.58%和74.52%、36.46%。浅淹组植株叶绿素含量、净光合速率、气孔传导率和蒸腾速率略有下降,分别为对照的95.39%、94.26%、90.02%和88.94%。深淹组植株在淹水后180d内上述参数显著下降,分别为对照的79.44%、73.54%、61.79%和71.46%,随后逐渐接近对照组。浅淹组PSⅡ的最大光化学量子效率(Fv/Fm)比较稳定,与对照组基本相同。深淹组在淹水后150d内Fv/Fm稍有下降,随后恢复到对照水平。浅淹组植株光化学淬灭系数(qP)稍有下降,非光化学淬灭(NPQ)略有上升,分别为对照的96.63%和105.66%。深淹组植株在淹水后120d内qP显著下降,NPQ明显上升,分别为对照的94.51%和126.66%,随后逐渐接近对照组。另外,淹水过程中,互叶白千层形成不定根和产生发达的通气组织,淹水植株的根孔隙度显著高于对照。

Effects of flooding depth on gas exchange, chlorophyll fluorescence and growth of Melaleuca alternifolia seedlings

The effects of flooding depth on gas exchange,chlorophyll fluorescence and growth of Melaleuca alternifolia seedlings were studied.Seedlings were subjected to two hydrological treatments:shallow flooding and deep flooding with water level at 5cm and 20cm above the soil surface,respectively.Results indicated that the effect of flooding on Melaleuca alternifolia was elevated with the increase in the flooding depth.After 270 days of flooding,the height and biomass of the shallow-flooded and deep-flooded seedli...