为确定适宜人参Panax ginseng叶面喷施的Zn浓度范围,采用田间试验的方法,研究喷Zn浓度对人参生长、皂苷含量及叶片吸收Zn速率的影响.结果表明,人参叶片可有效吸收叶面供给的无机态Zn2+,并可运至根部.在20～20000 mg/L质量浓度范围内,人参叶片吸收Zn的速率和数量与喷施浓度呈显著正相关(P＜0.01,R2＞0.9),而且随着喷施浓度的升高,从叶片向根部运输Zn的数量也升高.喷施适宜质量浓度(200和2000 mg/L)Zn2+可显著改善人参的Zn营养状况,促进人参生长和皂苷积累,增强叶片过氧化物酶(POD)和过氧化氢酶(CAT)活性.喷施浓度过高,人参叶片受到伤害,丙二醛(MDA)含量增加,CAT活性降低,但人参根皂苷含量显著升高,可能与环境胁迫刺激次生代谢产物积累有关.适宜人参叶面喷施的Zn质量浓度范围是200～2000 mg/L.%In order to identify appropriate Zn concentration range of foliar spraying for ginseng, effects of zinc spraying concentration on growth, ginsenoside content and zinc absorption efficiency by leaves of ginseng were studied through field experiments. Results showed that ginseng leaves can efficiently uptake Zn2 + of foliar applied, and transformation of Zn from leaves to roots was found. The amount of Zn uptake by leaves had significant (P 0. 9) positive correlation with applied Zn mass concentration range from 20 - 20 000 mg/L. As spraying concentration increased, the amount of zinc transferred from leaves to roots was also enhanced. Increment of fresh mass and ginsenoside content of root were found when appropriate Zn nutrient solution(200 and 2 000 mg/L) was applied, and peroxidases (POD) and catalase (CAT) activities increased when applied rate was 200 mg/L, but spraying 2 000 mg/L Zn2+ led to POD activity increase and CAT activity decrease compared to control. Although malondialdehyde ( MDA) content increased, CAT activity decrease and leaf burn were observed when 2 000 mg/L was supplied to ginseng leaves, and ginsenoside significantly increased in root. This may be due to of environmental pressure induced by secondary metabolite accumulation. Appropriate Zn mass concentrations of foliar application in ginseng ranged from 200 -2 000 mg/L.
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