低温胁迫对嫁接苦瓜幼苗抗氧化系统的影响

Effects of Low Temperature Stress on Antioxidant System of Grafted Bitter Gourd Seedlings

为研究低温胁迫对嫁接苦瓜幼苗生长及活性氧代谢系统的影响,以翠柳2号苦瓜为接穗,以苦砧2号(黄籽南瓜)和中原共荣(白籽南瓜)为砧木,利用靠接法进行嫁接,在人工气候箱内模拟低温胁迫条件,并对嫁接苦瓜幼苗的冷害指数和抗氧化系统的生理生化物质活性或含量进行测定。结果显示:在低温环境中,苦瓜嫁接苗与自根苗冷害指数以及抗氧化系统相关指标都会受到显著的影响。低温胁迫处理苦瓜自根苗的冷害指数显著升高,苦瓜嫁接幼苗冷害指数显著低于自根苗,说明嫁接可以显著提高苦瓜幼苗的对低温的耐受力。嫁接苗抗氧化酶活性以及抗氧化物质含量明显高于自根苗,而丙二醛(MDA)含量、过氧化氢(H_2O_2)以及超氧阴离子(O_2^(*-))的产生速率则显著低于自根苗,该结果说明嫁接能够降低低温胁迫所引起的活性氧积累和膜质过氧化对细胞膜造成的损伤。研究表明,低温胁迫下,苦瓜嫁接幼苗的抗氧化酶、抗氧化剂含量提高,可以维持AsA-GSH循环系统稳定性,降低了H_2O_2、MDA的累积以及产生速率,从而减轻活性氧对苦瓜幼苗的伤害,保护细胞膜结构的稳定性,增强了苦瓜幼苗的抗低温能力。

In order to study the effects of low temperature stress on the growth and active oxygen metabolism of grafted bitter gourd seedlings, Chui-liu 2 bitter gourd scions were grafted to Bitter Anvil 2 （yellow seed pumpkin） and Zhongyuan co-prosperity （white seed pumpkin） rootstocks The results showed that the cold injury index and the antioxidant system-related indexes of the grafted seedlings and the self-rooted seedlings were significantly affected in the low temperature environment. The chilling injury index of bitter gourd treated by low temperature was the highest, which indicated that grafting could effectively improve the tolerability of bitter to low temperature. But the MDA,I-1202, and were the lowest than those of the self-rooted seedlings. The results showed that the content of antioxidant enzymes and antioxidant activities were significantly higher than those of self-rooted seedlings under low temperature stress. Studies showed that under low temperature, the antioxidant enzymes and antioxidants in the grafted seedlings of Balsam pear increased tomaintain the stability of AsA-GSH circulatory system, and the accumulation of H202, MDA and the increase ofproduction rate reduced to alleviate the damage of reactive oxygen species to bitter gourd seedlings, and to protect the stability of cell membrane, and enhance the ability to resist low temperature.