豫楸1号4种砧木嫁接苗在干旱胁迫下保护酶系统的变化

Study on Systematic Changes of Protective Enzyme in Four Kinds of Grafting Stocks of Catalpa bungei "Yu-1" under Drought Stress

用盆栽自然干旱法对豫楸1号4种砧木嫁接苗进行干旱胁迫。在胁迫过程中,测定了超氧化物歧化酶(SOD)、过氧化物酶(POD)、过氧化氢酶(CAT)活性的变化。结果表明:在干旱胁迫下,豫楸1号4种砧木嫁接苗保护酶活性(SOD、POD、CAT)均随着干旱胁迫增加而呈现先上升后降低的变化趋势,其中POD、CAT的活性变化滞后于SOD。金丝楸砧木嫁接苗的保护酶值比其他嫁接苗大。金丝楸砧木嫁接苗的SOD值与梓树嫁接苗呈0.05水平显著差异,其CAT活性与灰楸嫁接苗、梓树嫁接苗呈0.05水平显著差异。从保护酶活性变化可以看出,SOD、CAT在清除氧离子自由基方面起到关键作用,豫楸1号4种砧木嫁接苗抗旱能力强弱依次为金丝楸嫁接苗>自砧苗>灰楸嫁接苗>梓树嫁接苗。

The activity of SOD,POD,CAT of four stocks grafted seedlings of Catalpa bungei ＂Yu-1＂ were systematic determined by natural drought way. The result showed： in the condition of drought stress, the protective enzyme activity（SOP,POD,CAT）of four stccks grafted seedlings of Catalpa bangei ＂Yu-l＂ presented the changing tendency that rises at first and reduces later with drought stress growing stronger. The changing of SOD were more early than POD and CAT. The protective enzyme activity of seedlings with Catalpa bungei as stccks was higher than the other three kinds of seedlings, and SOD had obvious difference（ P 〈 0.05） with grafted seedlings with Catalpa ovata. The drought tolerance of the four kinds of grafted-seedlings is in the order that grafted seedlings with Catalpa bungei 〉 grafted seedlings with serf 〉 grafted seedlings with Catalpa ovata 〉 grafted seedlings with Cata/pa fargesii.