锰胁迫对不同砧木苹果幼树锰吸收分配及抗氧化系统的影响

Effects of Mn Stress on Mn Uptakes and Antioxidant System of Young Apple Trees of Different Rootstocks

研究山荆子、八棱海棠和辽砧2号/山荆子3种砧木富士苹果在400 mg·kg-1锰胁迫条件下树体的生理响应和锰积累特征。结果表明,400 mg·kg-1锰胁迫下,3种砧木的富士苹果幼树叶片先后出现中毒症状,其中山荆子砧的幼树中毒最重,辽砧2号/山荆子砧次之,八棱海棠砧的最轻。400 mg·kg-1锰显著抑制了山荆子和辽砧2号/山荆子砧富士苹果幼树的生长,增加了锰在地上部的积累,却促进了八棱海棠富士苹果幼树地下生物量增加和锰在地下部的积累。过量锰导致山荆子和辽砧2号/山荆子苹果叶片自由基和丙二醛含量大量增加,超氧化物歧化酶活性和抗坏血酸含量增加较小,抗氧化物酶活性变化不明显。八棱海棠砧富士苹果幼树受锰胁迫后叶片抗氧化酶超氧化物歧化酶、抗氧化物酶、过氧化氢酶和抗氧化物质AsA活性显著提高,与锰胁迫前相比叶片自由基含量没有显著差异,丙二醛含量增加幅度较小。

To make clear the physiological responses of apple trees grafted on three rootstocks under high level of manganese stress. The physiological responses and manganese accumulation of three rootstocks on 400 mg · kgq manganese stress were studied. The results showed that toxic symptom happened in new leaves of all apple trees grafted on three rootstocks, which was the most serious in Malus baccata （Linn.） Borkh., followed by Liaozhen 2 inter stock, the most lightly in Malus prunifolia （Willd.） Borkh. Under 400 mg ~ kg-1 Mn stress, the growth of apple trees on Malus baccata （Lirm.） Borkh. and Liaozhen 2 inter stock were restrained significantly, but the growth of apple trees and Mn accumulation in underground parts on Malus prunifolia （Willd.） Borkh. were promoted, the contents of ROS and MDA were declined sharply, the SOD activity and AsA content increased slightly in apple leaves on Malus baccata （Lirm.） Borkh. and Liaozhen 2 inter stock. There were no significant difference of ROS content and a little rise of MDA content because of the much larger increases of antioxidant enzymes of SOD,POD, CAT and antioxidants such as AsA under the high level of Mn stress. The rootstocks of Malus prunifolia （Willd.） Borkh. had higher endurance to manganese toxcity, and Malus baccata （Lirm.） Borkh. and Liaozhen 2 inter stock were relatively lower.