淹水对三峡库区消落带香附子生理特性的影响

Effect of Submergence on Physiological Characteristics of Cyperus rotundus in Hydro-fluctuation Belt of Three Gorges Reservoir Area

为了阐明香附子对三峡库区消落带水淹的耐淹机理,该研究模拟三峡库区消落带夏季汛期水淹环境,设置常规水分管理(CK)、根部水淹(T1)、半淹(T2)以及全淹(T3)4个不同处理组,研究香附子对不同淹水环境的生理响应机制。结果显示:(1)经过45d的水淹处理,所有水淹处理香附子叶片叶绿素a、叶绿素b、类胡萝卜素以及总叶绿素的含量均显著下降,但叶绿素a/b值仍维持在CK水平;(2)淹水并没有增加T1和T3处理植株可溶性蛋白、脯氨酸和可溶性糖含量,但显著增加了T2植株叶片脯氨酸和可溶性糖的含量;(3)随着水淹时间的延长,各水淹处理植株叶片丙二醛含量逐渐升高,且自水淹15d后均与CK植株差异显著;(4)所有水淹处理香附子植株SOD、CAT和APX等抗氧化酶活性均有所增加,但随着水淹时间的继续延长,T3植株叶片SOD和CAT活性逐渐下降。(5)经过45d的水淹处理,各水淹处理植株淀粉含量在叶和根中均显著增加。研究表明,虽然淹水对香附子产生了一定的伤害,但香附子能够通过调节体内各种保护酶活性和渗透调节物质含量来增加对水淹的抵御能力,而且根部高浓度淀粉含量也为香附子耐受水淹胁迫提供了稳定的能量供应。

In order to explore the adaptation mechanism of Cyperus rotundus seedlings to the water level change in the hydro-fluctuation belt of the Three Gorges Reservoir area,we conducted a simulation experiment to study the physiology response to different submerged environments induced by the water level change.Four treatments were set,i.e.,no submergence（CK）,root submergence（T1）,semi-plant-submergence（T2）,and whole plant submergence（T3）.The results indicated that：（1）After treated for 45 days,chlorophyll a,chlorophyll b,carotenoid and total chlorophyll in all submergence treatments tended to be decreased,while chlorophyll a/b still kept the CK level.（2）Submergence had no significant effects on the contents of soluble protein,proline and soluble sugar in T1 and T3,but it significantly increased the contents of proline and soluble sugar in T2.（3）With the increase of submergence time,the content of MDA was gradually increased in all submergence treatments,and was significantly different compared with CK after 15-day submergence.（4）The activities of antioxidant enzyme（such as SOD,CAT and APX）in all submergence treatments had some increase during the submergence,however,the activities of SOD and CAT in T3 were gradually reduced as the submergence continue to increase.（5）After treated for 45 days,the starch concentrations in leaves and roots in all submergence treatments were higher than that in CK.This study indicates that although submergence have some adverse effects,C. rotundus can increase the physical defense to the submergence by adjusting a variety of inner protective enzyme activities and the contents of osmotic adjustment substances.Meanwhile,the accumulation of large amount of starch in root can offer a stable energy supply for tolerance to submergence.