【摘要】 为了研究沼气发酵液抑制西瓜枯萎病（ Ｆｕｓａｒｉｕｍ ｏｘｙｓｐｏｒｕｍ ｆ．ｓｐ ． ｎｉｖｅｕｍ） 的作用机理，使用不同来源和不同浓度的沼气发酵液处理西瓜植株，发现处理的植株体内的苯丙氨酸解氨酶（ Ｐ Ａ Ｌ） 的活性有显著升高，不同来源的沼气发酵液对植株的 Ｐ Ａ Ｌ活性都有不同程度的增加，并与黄腐酸的含量有一定相关性．用黄腐酸处理西瓜植株也可以诱导 Ｐ Ａ Ｌ 的产生更多还原

【Abstract】 In order to study the inhibition mechanism of anaerobically digested slurry to watermelon wilt ( Fusarium oxysporum f. sp. niveum ), the slurries from different sources and at different concentrations were used to treat watermelon seedlings. Phenylalanine ammonia lyase (PAL) activity of the seedlings treated with different sources of slurries increased, compared with CK. The increased PAL activity level was related to the fulvic acid content in the anaerobically digested slurry. The treatment of fulvic acid could induce PAL activity, compared with CK.更多还原