淹水胁迫及恢复对文冠果幼苗形态及生理特性的影响

Effects of waterlogging stress and restoration on morphological and physiological characteristics of Xanthoceras sorbifolia Bunge seedlings

【目的】研究文冠果苗不同淹水天数以及恢复后对其植株形态及生理特性的影响,探讨其在淹水胁迫下的适应性,为提高文冠果在南方地区的造林成活率和苗期的水分管理提供参考。【方法】以文冠果实生苗为材料,采用双套盆法模拟淹水环境,设置淹水0 d(CK)、淹水1 d(W1)、淹水3 d(W3)、淹水5 d(W5)、淹水7 d(W7)共5个处理,淹水结束后5个处理组均恢复正常水分管理7 d,观察不同处理组间苗木叶片的变化情况,比较不同处理组间植株根系活力、叶片渗透调节物质含量、抗氧化酶活性以及光合色素含量等生理指标的变化。【结果】随着淹水处理时间的延长,文冠果幼苗叶片逐渐变黄皱缩,甚至出现枯萎凋落等涝害症状,其根系活力及叶片光合色素含量逐渐降低,其中,与对照相比,W1、W3、W5和W7处理组根系活力分别降低22.8%、37.5%、50.5%和79.0%,总叶绿素含量分别降低2.8%、21.5%、27.1%和33.5%,类胡萝卜素含量分别降低1.8%、16.6%、22.1%和34.5%;叶片丙二醛和可溶性糖含量逐渐升高,其中,W1、W3、W5和W7处理组丙二醛含量与对照相比分别增加31.3%、73.0%、84.4%和112.8%,可溶性糖含量分别上升了59.6%、76.4%、106.4%和127.1%;而可溶性蛋白及脯氨酸含量则表现为先增加后减少的趋势,超氧化物歧化酶和过氧化物酶活性呈先升高后降低的趋势,并均在W3处理组达到峰值,与对照相比,分别增加了41.4%、76.1%、83.4%和55.6%。恢复正常水分管理7 d后,W1处理幼苗各项指标总体上均恢复至对照水平,而其余3个处理组各项指标总体上仍与对照有显著差异。【结论】综上所述,短期淹水(W1)后恢复正常水分管理7 d,文冠果幼苗的各项指标均能恢复正常水平,而中长期淹水处理(W3、W5、W7)后恢复正常水分管理7 d,植株的各项指标均未能恢复正常水平。

【Objective】We investigated the effects of different days of flooding and recovery on the morphological and physiological characteristics of the plants,and explored their adaptability under flooding stress,with a view to providing reference for improving the survival rate of Xanthoceras sorbifolia Bunge plantations and water management during the seedling period in the southern region.【Method】The X.sorbifolia Bunge seedlings were used as the material.The double set of potting method was used to simulate the flooded environment.A total of 5 treatments were set up,namely,0 days of flooding(CK),1 day of flooding(W1),3 days of flooding(W3),5 days of flooding(W5),and 7 days of flooding(W7),and the five treatment groups returned to normal water management for 7 days after the flooding.The changes of seedling leaves in different treatment groups were observed.The changes of physiological indexes such as root activity,leaf osmotic regulator content,antioxidant enzyme activity and photosynthetic pigment content were compared among different treatment groups.【Result】With the extension of the flooding treatment time,the leaves of the seedlings gradually turned yellow and shriveled,and even showed waterlogging symptoms such as wilted and withered,the root activity and leaf photosynthetic pigment content of the seedlings gradually decreased,in which,compared with the control,the root vigour of the W1,W3,W5 and W7 treatment groups were reduced by 22.8%,37.5%,50.5%,and 79.0%,and the total chlorophyll content was reduced by 2.8%,21.5%,27.1%and 33.5%,and carotenoid content decreased by 1.8%,16.6%,22.1%and 34.5%,respectively;the contents of malondialdehyde and soluble sugar in the leaves gradually increased,in which,malondialdehyde content increased by 31.3%,73.0%,84.4%and 112.8%in the W1,W3,W5 and W7 treatment groups,respectively,compared with the control,and soluble sugar content increased by 59.6%,76.4%,106.4%and 127.1%,respectively;while the soluble protein content,proline content,superoxide dismutase activity and peroxidase activity all showed a trend of first increasing and then decreasing,and all peaked in the W3 treatment group,which,compared with the control,increased by 41.4%,76.1%,83.4%and 55.6%,respectively.After 7 days of normal water management,all the indexes of W1 treatment seedlings recovered to the control level,while the indexes of the remaining 3 treatment groups were significantly different from the control.【Conclusion】In summary,after short-term flooding(W1)and normal water management for 7 days,all physiological indexes of seedlings could return to normal levels,while after long-term flooding(W3,W5,W7),all indicators of plants could not return to normal levels.