西瓜幼苗抗氧化系统对淹水胁迫的响应  

Response of antioxidant defense system in watermelon seedling subjected to waterlogged stress

作　　者：刘文革[1] 阎志红[1] 王川[1] 张红梅[1] 

机构地区：[1]中国农业科学院郑州果树研究所,郑州450009

出　　处：《果树学报》2006年第6期860-864,共5页Journal of Fruit Science

基　　金：国家863计划子课题项目(2004AA241170);河南省自然科学基金项目(0511030800);河南省重点科技攻关项目(05230011800)。

摘　　要：为了研究西瓜植株在淹水情况下对淹水胁迫的响应,以蜜枚(M2x)和京牟(JM2x)2个二倍体西瓜品种为试材,在盆栽条件下研究了淹水胁迫对西瓜叶片受害指数、生理生化特性的影响。结果表明,西瓜幼苗在淹水胁迫下,真叶发黄失绿,随着淹水时间延长,茎开始腐烂,出现气生根,30d后淹水解除,植株生长无法恢复。西瓜幼苗叶片SOD活性在淹水初期下降,随着西瓜幼苗对淹水胁迫的适应,SOD开始回升,在胁迫8d后超出对照。淹水胁迫后西瓜幼苗叶片POD活性一直是上升趋势且高于对照。可溶性蛋白质含量受涝害后都比对照降低。随着淹水胁迫增加,PRO降低幅度加大。MDA含量受淹水胁迫后都比对照上升,MDA含量先降,后升高,再降低,然后大幅度升高。根据试验结果推断西瓜叶片伤害顺序为,SOD活性受抑制→活性氧增生→SOD、POD活性、PRO含量增加→清除活性氧→淹水胁迫加深→活性氧再增加→MDA积累→保护酶活性降低→质膜受损。京牟西瓜品种的耐淹水能力强于蜜枚。Two watermelon lines were pot-cuhured and then waterlogged in 4 leaf stages and were used for studying mechanism of antioxidant defense system in watermelon seedling subjected to waterlogged stress. The effect of waterlogged stress on damage index of seedling leaf, physiological and biochemical characteristics of watermelon were studied. The results showed that the true leaf became yellow and lack of chlorophyll after waterlogged. The seedling stem was rotten and aerial root were produced after waterlogged stress as to adapt to the stress evolution. The plant had not developed after waterlogged for 30 days. SOD activities of leaf of two watermelon lines decreased at beginning and then increased, until to approach the control, and the extent of increased SOD of JM2x were higher than M2x. It demonstrated that seedling of watermelon possessed a significantly larger self-regulating ability. In contrast, POD activities of all were higher than the control, the extent of increased of JM2x were higher than that of M2x; PRO contents of all treatment after flooding stress was lower than the control, the extent of decreased of JM2x were higher than that of M2x ; MDA contents of all were higher than the control after submergence, the MDA contents in tolerance increased firstly, then decreased ; In contrast, the MDA contents of M2x in sensitive decreased slightly at flint, then increased significantly. According to the changes of SOD and POD activities, PRO and MDA contents after submergence,the changes of leaf damage were concluded：restrain SOD activities→oxidative increase SOD, POD activities and PRO contents increase→eliminate oxidative→submergence stress→oxidative increase again→MDA accumulate→SOD POD activities decrease→damage to cellular membrane. The resistance to waterlogged stress of JM2x was higher than that of M2x.

关 键 词：西瓜 幼苗 淹水胁迫 抗氧化系统 

分 类 号：S651[农业科学—果树学]