淹水对牡丹生理特性的影响

Effect of waterlogging on physiological characteristics of peony

为探究牡丹对淹水的响应,以牡丹品种"乌龙捧盛"为试材,研究了人工模拟4个不同程度淹水处理对牡丹植株的形态、光合特性、抗氧化酶和渗透调节物质的影响。结果表明:轻度淹水处理对牡丹植株形态没有明显的影响,深度淹水处理组较早出现萎蔫,后期植株受到严重伤害。随淹水时间的延长,轻度淹水处理的叶绿素含量变化不明显,而深度淹水处理的叶绿素a和叶绿素(a+b)含量逐渐降低;不同处理牡丹叶片的净光合速率(Pn)、蒸腾速率(Tr)和气孔导度(Gs)持续下降,胞间CO2浓度(Ci)则逐渐增加;各处理组的丙二醛(MDA)含量、过氧化物酶(POD)和抗坏血酸过氧化物酶(APX)活性均随胁迫时间的延长持续增加,超氧化物歧化酶(SOD)、过氧化氢酶(CAT)和谷胱甘肽还原酶(GR)活性及可溶性糖和脯氨酸含量在轻度淹水处理组逐渐增加,而在深度淹水处理组则呈现先升高后降低的变化趋势。因此,深度淹水胁迫下牡丹的生长和光合机构受到了一定程度的损伤,抗氧化酶和渗透调节物质的积累对提高植株的耐淹性起到了一定的调节作用。

In this paper, the changes in plant morphology, photosynthetic characteristics, anti- oxidase and osmotic regulation substance of peony （Paeonia suffruticosa cv. Wulongpengsheng） under flooding of four degrees were measured to study the response of peony to flooding stress. The results showed that light flooding had no significant influence on the morphology of peony plants. The peony plants became wilting quickly under severe flooding stress and then suffered a serious damage. There was no obvious change in the chlorophyll contents of peony leaves under light flooding stress, however, the contents of chlorophyll a and （a＋b） of leaves under severe flooding stress decreased gradually over time. The net photosynthetic rate （Pn）, transpiration rate （ Tr） and stomatal conductance （ Gs） of leaves kept decreasing, while the intercellular CO2 con- centration （ Ci） increased over time. The content of MDA and the activities of POD and APX in- creased over time. The activities of SOD, CAT, GR and the contents of soluble sugar and proline gradually increased in plants under light flooding stress, but increased at first and then decreased in plants under severe flooding stress. These results suggested that the growth and photosynthetic apparatus of peonies were damaged to a certain degree under severe flooding stress. The accumu- lation of antioxidation enzymes and osmotic adjustment substances could improve the resistance and adaptation of peonies to flooding stress.