【摘要】 以1年生火力楠幼苗为试材,通过甜菜碱（BT）、氯化钙（CaCl₂）、茉莉酸甲酯（MeJA）和水杨酸（SA）4种外源物质进行处理,研究其对300 mmol·L^-1 NaCl胁迫下火力楠幼苗相对电导率、叶绿素、可溶性糖和蛋白质量分数、过氧化氢酶（CAT）、过氧化物酶（POD）、超氧化物歧化酶（SOD）活性的影响。结果表明:（1）单盐胁迫下火力楠幼苗的相对电导率、SOD活性显著升高,可溶性糖质量分数和CAT活性升高,POD活性先升高后下降,叶绿素、可溶性蛋白质量分数下降。（2）喷施适宜浓度的不同外源物质后叶片相对电导率显著降低,可溶性糖和可溶性蛋白质量分数明显增多,CAT、POD、SOD活性显著增强,叶绿素质量分数变化不大。（3）利用隶属法进行综合评价结果显示4类外源物质缓解火力楠幼苗盐伤害作用效果排序由大到小为MeJA、SA、CaCl₂、BT。喷施外源3 mmol·L^-1 MeJA最能减少盐胁迫对火力楠幼苗的伤害,其次为100 mg·L^-1 SA、5 mmol·L^-1 CaCl₂处理。更多还原

【Abstract】 With the one-year-old seedlings of Michelia macclurei, which were treated with different concentrations of exogenous betaine（BT）, calcium chloride（CaCl₂）, methyl jasmonate（MeJA） and salicylic acid（SA）, we studied the effects of exogenous substances on the relative conductivity（RC）, the content of chlorophyll（SPAD）, soluble sugar（SS）, soluble protein（SP） and the activity of antioxidant enzymes（SOD, POD, CAT） of M. macclurei under 300 mmol·L^-1 NaCl stress. The leaf relative conductivity, SOD activity significantly increased, SS and CAT increased, POD activity increased first and then decreased, the contents of SPAD, SP decreased under 300 mmol·L^-1 NaCl stress alone. After spraying suitable concentrations of four exogenous substances, RC of leaves decreased significantly, but the contents of SS and SP increased and SOD, POD, CAT activity increased significantly, the content of SPAD changed little. Subordinate function values analysis results show that the effects of four kinds of exogenous substances on alleviating salt injury of M. macclurei seedlings were ranked in descending order of MeJA, SA, CaCl₂ and BT. The 3 mmol·L^-1 MeJA produced the best effects of reduce damage, followed by 100 mg·L^-1 SA and 5 mmol·L^-1 CaCl₂.更多还原