滨麦对海岸沙丘环境异质性的生理适应分析

Characteristics Analysis of Physiological Adaptation of Leymus moillis Grown in Different Slope of Coastal Dunes to Heterogeneous Environment

本实验以烟台海岸沙丘为试验地,以距海岸高潮线不同距离的沙丘迎风坡(10,30,50 m)和背风坡(7 0m)生长的滨麦(Leymus mollis(Trin.)Hara)为材料,通过在夏季高温、无风时对沙丘不同坡向样地环境因素和滨麦叶片叶绿素的含量、丙二醛(MDA)含量、超氧化物歧化酶(SOD)、过氧化物酶(POD)、过氧化氢酶(CAT)以及渗透调节物(可溶性糖、脯氨酸)含量的测定和分析,以探讨不同坡向滨麦适应异质环境的生理调节机制.研究表明,迎风坡近高潮线(10m)处风速较高、温度低、土壤盐度和含水量高.相比之下,背风坡(70 m)风速较低、温度高、土壤盐度和含水量低,高温干旱是生长抑制因子.生活在海岸不同样地异质环境的滨麦在抗氧化酶种类和渗透调节物种类上存在差异.近高潮线迎风坡(10 m)滨麦叶绿素含量高、MDA含量高、SOD和CAT活力高、可溶性糖含量高;背风坡(70 m)生长的滨麦叶片叶绿素含量低、MDA含量低、SOD和CAT活力也低,POD的活力却很高、脯氨酸含量高.在近海岸高盐环境中生长的滨麦通过提高可溶性糖含量,SOD和CAT活力维护氧自由基代谢平衡,而在高温干旱环境中生长的滨麦通过提高脯氨酸含量和POD活力维护氧自由基代谢平衡.可见,滨麦在长期适应迎风坡高盐环境和背风坡高温干旱环境生长中,在抗氧化酶种类和渗透调节物种类方面存在差异,表现出明显的抗逆生理调节可塑性.滨麦抗逆生理可塑性调控作用在其适应海岸异质环境中起重要作用.

Leymus mollis grown on different sand dunes of 10 m,30 m,50 m( windward slope) and 70 m( leeward slope) far from the high tide on the coastal of Yantai was chosen to be a material used for this study. The environmental ecological factors and the contents of soluble sugar,proline,chlorophyll and the activities of antioxidant enzymes( SOD,POD and CAT) in the leaves of L. mollis grown in different location away from high tide line were measured to understand the adaptive mechanisms in biochemical and physiology for L. mollis to heterogeneous environment. The results showed that there was different environment between windward slope and leeward slope of coastal dune. On windward slope closed to high tide line(10 m),it was higher in sea-wind speed,salt content,water content. On leeward slope of coastal dune( 70 m),it was higher in temperature,and lower in water content and salt content. The leaves of L. mollis grown in windward slope(10 m) had higher contents of chlorophyll,MDA and soluble sugar,and higher activities of SOD and CAT. In contrast,the leaves of L. mollis grown in leeward slope(70 m) had lower contents of chlorophyll,MDA and proline,and lower activities of SOD,CAT and higher activities of POD. It indicated that there were markedly differences in kinds of antioxidant enzymes and osmosis-regulating substances between the leaves of L. mollis grown in windward slope and leeward slope. It presented that different environment between windward slope and leeward slope made L. mollis grown on both side slope form different adaptive mechanism,which showed L. mollis have strong regulative ability of physiological plasticity. The characteristics of physiological plasticity played very important role for L. mollis in adapting coastal environment of heterogeneity.