高温胁迫下菊花嫁接苗中保护酶活性的变化

Response of protective enzymes activities in grafted chrysanthemum to heat stress

【目的】探讨嫁接对菊花耐热性的影响机理及对菊花不同器官耐热性的影响。【方法】比较40℃高温胁迫下菊花嫁接苗和不同生育期扦插苗的叶片、根系和茎段中超氧化物歧化酶(SOD)、过氧化物酶(POD)、过氧化氢酶(CAT)活性的变化与差异。【结果】菊花嫁接苗根茎叶中3种保护酶活性均显著高于扦插苗。与扦插苗相比,嫁接苗叶片、根系和茎段中SOD、POD和CAT活性分别平均提高11.6%,378.0%,260.1%;125.5%,131.3%,203.1%;90.1%,98.0%,90.5%。嫁接苗叶片中以SOD活性最大,均值达375U/g;根系中以POD活性最大,均值达605.87U/g;茎段中3种保护酶活性差异较小,以POD活性略高。【结论】嫁接是提高菊花耐热能力的一项有效措施,嫁接苗根茎叶的耐热性差别显著。

[Objective] This study investigated the effects of grafting on heat resistance of different or- gans of chrysanthemum. [Method] The activities of superoxide dismutase （SOD）, peroxidase （POD） and catalase （CAT） in leaves,roots and stems of grafted and cutting seedlings of chrysanthemum were studied at temperature of 40 ℃. [Result] The SOD,POD,and CAT activities in leaves,roots and stems of grafted chrysanthemum seedlings were significantly higher than that of cutting ones. The average SOD,POD,and CAT activities in leaves,roots and stems increased by 11.6% ,378.0% and 260.1% ;125.5%,131.3% and 203.1% ;and 90.1% ,98.0% and 90.5%,respectively. In leaves of grafted seedlings,SOD activity had the largest value of 375 U/g. In roots of grafted seedlings,POD activity had the largest value of 605.87 U/g. In stems of grafted seedlings, POD activity was slightly higher than the other two. [Conclusion] Grafting is an effective cultivation method to improve the resistance of chrysanthemum to heat stress. The heat resist- ances of different organs are significantly different.