海岸和内陆沙地砂引草(Messerschmidia sibirica)对自然环境和沙埋处理适应的生理差异

Physiological Difference in Messerschmidia sibirica Grown in Inland and Coastal Sand Land in Nature Environment and under Sand Burial

砂引草(Messerschmidia sibirica)是一种耐盐、耐旱固沙地被植物,既能生长在海岸沙地并成为优势植物,也在内陆干旱沙地有分布。本文以科尔沁内陆沙地和烟台海岸沙地生长的砂引草为试验材料,研究了两沙地土壤化学特性、水温特性及在自然状况和沙埋胁迫条件下两沙地砂引草叶片丙二醛(MDA)含量、抗氧化酶活力和渗透调节物含量的变化特征。结果表明:(1)海岸沙地土壤含盐量较内陆沙地高5倍,但土壤地表温度略低。(2)在自然和沙埋条件下,两沙地砂引草叶中MDA含量较低。(3)生活在内陆干旱高温沙地上的砂引草,在自然和沙埋处理中叶片平均脯氨酸和可溶性糖含量均高于海岸沙地砂引草,自然状况下,其叶片平均脯氨酸和可溶性糖含量分别较海岸沙地的高25%~50%和高3.5倍。(4)海岸沙地砂引草在自然和沙埋处理5d和10d中,其叶片平均超氧化物歧化酶(SOD)、过氧化物酶(POD)、过氧化氢酶(CAT)活力均大于内陆沙地砂引草,且两者差异显著(p<0.05),自然状况下海岸沙地砂引草叶片SOD、POD、CAT平均活力分别较内陆高14%、140%和118%。(4)两沙地砂引草对沙埋胁迫的生理响应类似,随着沙埋强度的增加砂引草沙上叶片MDA含量变化不大,SOD和CAT活力和脯氨酸含量增加,可溶性糖含量下降。研究表明,砂引草具有在不同环境下利用不同渗透调节剂维护水分代谢平衡、提高抗氧化酶活力抑制膜脂过氧化维持氧自由基代谢平衡的生理调控能力,该生理可塑性可能是其具有较宽生态幅的生理基础。

Messerschmidia sibiricais a ground cover plant with higher resistance to salt,drought and sand-fixation,and is a dominant plant in coastal sand land(CSL)and also grow in inland sand land(ISL).In this paper,M.sibirica grown in Horqin Sandy Land(ISL)and coastal sand land in Yantai were used as material.The soil chemical properties and temperature and water content in both two sand lands,and malondialdehyde(MDA)content,the activities of antioxidative enzyme and osmoregulation substance contents in leaves of M.sibirica were measured in nature environment(NE)and under sand burial(SB).The results showed that:(1)The soil in CSL had higher in Na+content by 5times than that of ISL,but had lower surface temperature than ISL.(2)The leaves of M.sibiricafrom both sand lands kept lower MDA content in NE and under SB.(3)The leaves of M.sibirica grown in ISL with drought and higher temperature had higher contents in proline and soluble sugar than that of CSL in NE and under SB.For instance,in NE,the contents of proline and soluble sugar in leaves of M.sibirica from ISL were higher by 25%-50%,and 3.5 times than that from CSL.(4)The leaves of M.sibirica grown in CSL had higher activities of superoxide dismutase(SOD),peroxidase(POD),catalase(CAT)than that of ISL in NE and under SB for 5 days and 10 days,for instance,in NE,it had higher in the activities of SOD,POD,CAT by 14%,140% and 118% than that from ISL.(4)Both M.sibirica grown in ISL and CSL had same response to SB.The content of proline and activities of SOD and CAT increased,and content of soluble sugar decreased in the leaves above sand with increasing of sand burial depth.It suggest that M.sibirica had a higher ability of physiological regulation by changing osmotic regulator in maintaining water metabolism balance,and increasing activities of antioxidative enzyme to inhibition of lipid peroxidation,which would be foundation of physiological plasticity for it to have a wider ecological amplitude.