高氮磷胁迫下菖蒲(Acorus calamus Linn.)通气组织和根系释氧的响应

Response between aerenchyma and radial oxygen loss of Acorus calamus Linn.under high nitrogen and phosphorus stress

以湿地植物菖蒲为研究对象,在水培条件下观察3个浓度梯度的氮磷污水(处理组1、2、3依次为N:40 mg/L、P:4 mg/L;N:80 mg/L、P:8 mg/L;N:120 mg/L、P:12 mg/L)对其胁迫后的根系释氧和通气组织的变化规律,研究发现高氮磷胁迫明显抑制菖蒲株高和根系长度的生长,减少植物根系数量;高氮磷胁迫还可以增加植物根系释氧量和促进根系通气组织形成,由于根系长度和数量的减少,处理组的根系释氧总量不及对照组;高氮磷胁迫不改变菖蒲根系释氧趋势,根尖最大,离根尖越远释氧越小.研究还发现,根尖释氧量大小和通气组织呈正相关,根基和根中部释氧量与通气组织关系不显著,说明植物通气组织的形式更有利于根尖释氧.

Acorus calamus Linn. has been selected as the experimental plant, and the variation of its aerenchyma and the quantity of its radial oxygen loss （ROL） under the stress of three different concentrations of nitrogen and phosphorus effluent （ Group 1 ： N 40 mg/L, P 4 mg/L; Group 2 ： N 80 mg/L, P 8 mg/L; Group 3 ： N 120 mg/L, P 12 mg,/L） in the water culture has been investi- gated. The results show that the stress of high concentrations of nitrogen and phosphorus significantly inhibited the growth of root length and plant height of Acorns calamus Linn. and reduced the number of plant roots ; it could also increase the quantity of ROL and promote the formation of aerenchyma. The gross quantity of ROL in the stress group was less than that in the control group due to the decrease of root length and quantity. The ROL trend has not changed by the stress of high concentrations of nitrogen and phosphorus, and the further distance away from the roots, the smaller quantity of the ROL. This research also found that the amount of the root tip＇s ROL showed positive correlation with aerenchyma while the amount of ROL of basal zone and mature zone showed insignificant correlation with the aerenchyma.