柳杉凋落物自毒作用研究

采用种子萌发法对浙江天目山柳杉Cryptomeria fortunei凋落物的自毒作用进行了研究，以探究这种凋落物的自毒作用对柳杉天然更新障碍的影响。结果表明，柳杉凋落物及其表层土壤浸提液在质量体积比为1 ∶ 10时，对柳杉种子萌发具有抑制作用。随着浸提液比例的降低（1 ∶ 100），抑制作用减弱，甚至消失（1 ∶ 250）。自毒作用强度为未分解凋落物＞半分解凋落物＞表层土壤。而且未分解凋落物浸提液的化感作用强度随着样品含水率的增大而增强。通过高效液相色谱仪测定发现，柳杉凋落物和表层土壤中均含有酚酸类化感物质阿魏酸、肉桂酸和对羟基苯甲酸，而且未分解凋落物中的这3种物质的含量均是最高的。综合推测，这3种化感物质主要来自于未分解的柳杉凋落物。图2表4参22

Autotoxicity of Cryptomeria fortunei litter

To determine the influence of autotoxicity on natural regeneration of Cryptomeria fortunei, seed germination in water extract of C. fortunei litter was researched with treatments of 1 ∶ 10, 1 ∶ 100, 1 ∶ 200, and 1 ∶ 250 （litter water extract volume： distilled water volume）. Results showed that the high extract concentration （1 ∶ 10） restrained C. fortunei seed germination. Restraint intensity declined as the concentration decreased with a restraint intensity order of： undecomposed litter semi-decomposed litter soil. High performance liquid chromatograph （HPLC） was used to analyze autotoxins components of ferulic acid （FA）, cinnamic acid （CA）, and β-hydroxybenzoic acid （β-HA）. Also, autotoxin content identified in undecomposed litter was greater than semi-decomposed litter and soil combined. Thus, undecomposed litter was the primary source of released autotoxins.