外源硒对梨树叶片衰老和光合同化物积累的影响  

Effects of Exogenous Selenium on Leaf Senescence and Photo-assimilates in Pear Leaves during the Senescing Period

作　　者：刘群龙[1] 宁婵娟[1] 郝燕燕[1] 吴国良[2] 郝国伟[3] 牛铁泉[1] 

机构地区：[1]山西农业大学园艺学院,山西太谷030801 [2]河南农业大学园艺学院,郑州450002 [3]山西省农业科学院果树研究所,山西太谷030815

出　　处：《水土保持学报》2014年第6期314-318,共5页Journal of Soil and Water Conservation

基　　金：国家梨产业体系建设专项(Nycytx-29-30);河南省重大科技攻关项目(092101110600);山西省科技产业化环境建设项目(2006071024);山西省星火计划项目(20090510012)

摘　　要：采用叶面喷施方式,研究不同浓度(0,5,10,20mg/L)Na2SeO3处理对7年生砀山酥梨叶片衰老及其光合作用的影响。结果表明:与对照相比,5mg/L硒可降低梨树叶片衰老进程中的质膜相对透性以及丙二醛(MDA)和脯氨酸含量,提高其净光合速率(Pn)以及谷胱甘肽(GSH)、抗坏血酸(AsA)和淀粉含量;至采样后期,5 mg/L硒使质膜相对透性以及MDA和脯氨酸含量分别较对照极显著降低18.05%,36.24%和39.42%,GSH含量显著提高25.43%,AsA含量极显著提高13.44%,从而使叶片衰老延缓,并使采样后期叶片Pn和淀粉含量分别较对照极显著提高59.98%和36.58%。随喷硒浓度增加,硒的过氧化作用逐渐显现和增强,至采样后期,20mg/L硒使质膜相对透性以及MDA和脯氨酸含量分别较对照显著提高14.34%,16.89%和8.97%,GSH和AsA含量分别极显著降低32.39%和15.68%,从而使叶片衰老加速,并使采样后期叶片Pn较对照极显著降低59.89%。硒对衰老叶片还原糖和可溶性糖含量影响不显著。因此,对梨树喷硒时,从延缓叶片衰老、提高叶片Pn和光合同化物积累等方面考虑,应以5mg/L为宜。Pyrus bretschneider cultivar‘Dangshan Suli＇trees of seven-years-old were used as materials and different concentrations of sodium selenite（0,5,10,20mg/L）were sprayed to the trees for analyzing the effects of selenium on leaf senescence and its photosynthesis.The results indicated that：Compared with the control,the Se dosage of 5mg/L could reduce the membrane permeability,the malondialdehyde（MDA）and proline content,increased the net photosynthetic rate（Pn）,as well as the glutathione（GSH）,ascorbic acid（AsA）,and starch content.Compared with the control,the lower Se dosage（5 mg/L）was sprayed,the membrane permeability,the MDA and proline content of the later leaves were decreased very significantly by18.05%,36.24% and 39.42% respectively,the GSH content were increased significantly by 25.43%,the ASA content were increased very significantly by 13.44%,thus the functional period of the leaves was postponed,the Pnand the starch content of the later leaves were increased by 59.98%and 36.58%respectively.With increasing Se concentration,antioxidation was gradually weakened and peroxidation was gradually enhanced.On the contrary,compared with the control,when higher Se dosage（20mg/L）was sprayed,the membrane permeability,the MDA and proline content of the later leaves were increased significantly by14.34%,16.89% and 8.97%,the GSH and AsA content were decreased very significantly by 32.39% and15.68%respectively,thus leaf senescence was accelerated and the Pnof the later leaves was decreased very significantly by 59.89%.However,the effect of selenium on the reducing and soluble sugar content was not significant.So,when spraying Se to the pear trees,the dosage of 5mg/L was the most appropriate concentration in order to delay leaf senescence,increase the Pnand its photo-assimilates.

关 键 词：梨树 硒 衰老 抗氧化剂 光合同化物 净光合速率 

分 类 号：Q945.11[生物学—植物学] S661.2[农业科学—果树学]