遮荫对半夏叶片光合色素与保护酶活性的影响

对半夏进行不同程度遮荫处理,研究了其生长过程中叶组织的光合色素含量、叶绿素a/b值、保护酶体系(SOD、POD、CAT)活性和丙二醛(MDA)含量的变化及其生理特性.结果表明:不同处理的半夏在生长过程中,光合色素的含量呈先升后降的趋势;与全光照相比,遮荫处理的叶绿素含量较高,叶绿素a/b值较低,类胡萝卜素含量在生长发育中早期较低而后期较高;SOD、POD、CAT活性呈由低到高再降低的趋势,MDA含量持续升高;遮荫处理的SOD、POD活性和MDA含量均低于全光照处理,CAT活性则表现为先高于后低于全光照处理.适度的遮荫可以提高半夏叶绿素的含量,降低膜系统受到的伤害,改善半夏的倒苗状况,为半夏叶片的生长提供较好的环境.

Effect of Shading on the Photosynthetic Pigment and Protective Enzyme Activities in Pinellia ternata Leaves

The photosynthetic pigment contents,chlorophyll a/b rate,malondialdehyde(MDA) contents,and superoxide dismutase(SOD),peroxidase(POD),catalase(CAT) activities in the leaves of Pinellia ternata(Thunb.) Breit.which was under different light intensities during their growth were studied.The results showed that contents of photosynthetic pigment increased first and then decreased in the process of leaf senescence.Being treated with shading,contents of chlorophyll were higher,chlorophyll a/b rate was lower,contents of carotenoid were lower at prophase and metaphase growth stages,while higher at the evening developmental stages.SOD,POD and CAT activities increased first and then decreased,while MDA contents always increased.SOD,POD activities and MDA contents under shading treatment were lower than full light treatment.CAT activities were higher at prophase and metaphase growth stages,while lower at the evening developmental stages.The moderate shading can improve contents of chlorophyll,reduce contents of MDA,improve the status of sprout tumble and provide better condition for the development of P.ternata.