施硒和6-BA对葡萄叶片衰老与活性氧代谢的影响

Effects of selenium and 6-BA on leaf senescence and active oxygen metabolism in grape

【目的】明确氨基酸硒和6-BA对葡萄叶片衰老与活性氧代谢的影响,为延缓叶片衰老技术的提出提供理论依据。【方法】以设施延迟栽培条件下叶片衰老速度不同的‘意大利’和‘无核白鸡心’2个葡萄品种为试材,分别进行叶面喷施氨基酸硒和6-BA处理,以喷施等量清水作为对照,研究施硒及6-BA对叶片衰老期间各功能叶片的叶绿素含量、净光合速率(Pn)、丙二醛(MDA)含量和超氧阴离子自由基(O2·)、过氧化氢(H2O2)含量及过氧化氢酶(CAT)、过氧化物酶(POD)、超氧化物歧化酶(SOD)抗氧化酶活性的影响。【结果】与对照相比,外源氨基酸硒和6-BA处理显著延缓了叶片的叶绿素含量和净光合速率(Pn)的下降,提高了过氧化氢酶(CAT)、过氧化物酶(POD)、超氧化物歧化酶(SOD)的活性,从而减慢了丙二醛(MDA)、超氧阴离子自由基(O2·)、过氧化氢(H2O2)的上升速率,延缓了叶片衰老。2个品种间比较,‘意大利’叶片衰老缓慢,在生育后期仍能维持较高的抗氧化酶活性。【结论】氨基酸硒和6-BA处理可有效提高叶片的抗衰老能力,延长叶片的功能期。

【Objective】To investigate the effects of selenium and 6-BA on leaf senescence and active oxy-gen metabolism in order to provide a theoretical basis for preventing leaves from early aging.【Methods】The two grape varieties Italia and Centenial seedless with different senescence-types cultured in protect-ed and delayed cultivation system were studied. Amino acid selenium and 6-BA were sprayed on thegrape leaves with equivalent clean water as control(CK).The physiological indexes of their leaves,suchas chlorophyll contents and net photosynthetic rate,superoxide radical and hydrogen peroxide contents,malondialdehyde accumulation,superoxide dismutase,peroxidase and catalase activities were deter-mined during natural senescence.【Results】Compared with control(CK),exogenous amino acid seleniumand 6- BA delayed the decrease of chlorophyll content and net photosynthetic rate significantly,in-creased the superoxide dismutase,catalase and peroxidase activities,decreased the content of malondial-dehyde,superoxide radical and hydrogen peroxide and postponed the senescence of functional leaves.There were differences between different senescence-types of grape leaves,the leaves of Italia aged slow-er and antioxidant enzymes maintained higher activities at the late growth stage.【Conclusion】The results indicated that the application of amino acid selenium and 6-BA effectively improved the leaf anti-agingproperties and prolonged the functional period of the leaves.