在前期巨桉挥发性物质鉴定及其林龄效应研究的基础上, 结合预备实验选择含量较高且随林龄变化较为明显的两种挥发性化合物 (正癸烷和2, 2, 4, 6, 6-五甲基庚烷), 研究其对受体植物 (萝卜Raphanus sativus、绿豆Vigna radiata、莴苣Lactuca sativa) 萌发、生长及四种生理指标的影响.结果显示:1) 两种化感物质对三种受体植物种子萌发均具有抑制作用, 且随浓度升高而增强.两物质对三种受体植物根长呈低促高抑现象且随浓度的增加抑制作用逐渐增强.正癸烷对三种受体植物苗高具有低浓度促进高浓度抑制作用;2, 2, 4, 6, 6-五甲基庚烷对萝卜和莴苣苗高具有低促高抑的作用, 对绿豆苗高呈现高浓度显著抑制作用.正癸烷对萝卜、绿豆苗/根鲜重比随浓度增加呈现不显著或促进作用, 对莴苣苗/根鲜重比作用不显著;2, 2, 4, 6, 6-五甲基庚烷对萝卜和绿豆的苗/根鲜重比呈现低浓度无显著变化高浓度促进作用, 而对莴苣苗/根鲜重比影响不显著.2) 正癸烷和2, 2, 4, 6, 6-五甲基庚烷对莴苣、2, 2, 4, 6, 6-五甲基庚烷对萝卜的SOD活性含量无显著影响, 这两种物质对其它受体植物的SOD、CAT活性均具有低浓度促进或影响不显著, 高浓度时显著抑制作用.两物质对三种受体植物MDA含量具有低浓度抑制或无显著变化, 高浓度促进作用.两种化感物质对三种受体植物幼苗根系活力 (TTC) 均呈现低浓度促进或影响不显著高浓度抑制作用.%On the basis of identification of volatile compounds across a range of E.grandis plantation ages and through preliminary experiments, two volatile compounds (Decane and 2, 2, 4, 6, 6-Pentamethyl-heptane) were selected to evaluate their effects on the seed germination, seedling growth and four physiological indexes of three target plants (Raphanus sativus, Vigna radiate, Lactuca sativa).The results showed that the two volatile compounds exerted inhibitory effects on the seed germination of three target plants, and the inhibitory effects were strengthened with the increasing concentrations.The roots length was stimulated at lower dose but was inhibited at higher concentrations, and the effects were strengthened with the increasing concentrations.The shoot height of three target plants under the treatment of decane was stimulated at lower concentrations, and was inhibited at higher dose.Under 2, 2, 4, 6, 6-pentamethyl-heptane treatment, the shoot height of Raphanus sativus and Lactuca sativa was stimulated at lower concentrations and was inhibited at the higher concentrations, but that of Vigna radiate was inhibited significantly at the higher concentrations.There were no obvious effects of 2, 2, 4, 6, 6-pentamethyl-heptane on the seedling/root fresh weight ratio of Raphanus sativus and Vigna radiate at lower concentration but represented significantly stimulative effects at higher concentrations, but the effect on seedling/root fresh weight ratio of Lactuca sativa was not obvious with the increasing concentrations.2) The SOD activities of Lactuca sativa under the treatments of decane and2, 2, 4, 6, 6-Pentamethyl-heptane, and those of Raphanus sativus under the treatment of 2, 2, 4, 6, 6-Pentamethyl-heptane were not significantly changed with the increasing concentrations.All the other treatments stimulated or represented no significant effects on the SOD and CAT activities of target plants at lower concentrations, but the two enzyme activities were inhibited at higher concentrations.The two chemicals were apparently reduced or showed no significant effects on the MDA content of target plants at lower concentrations, but stimulated at higher concentrations.The TTC contents of the three plants were promoted or not obviously affected at lower concentrations, but were inhibited at higher concentrations.
展开▼
