Harpin或BTH诱导厚皮甜瓜抗菌物质的研究

Preformed antifungal compounds induced by Harpin and BTH treatments in leaves of muskmelons

以50mg/L Harpin或100mg/L BTH作为诱抗剂,分别研究两者对植物生长期间合成抗菌物质的影响,分布于叶片的抗菌物质以甲醇-二氯甲烷浸提,薄层层析色谱(TLC)分离,并以A.alternata为指示菌,对其抑菌带的抗菌物质进行气相色谱-质谱联用(GC-MS)分析。结果表明:甜瓜叶片中存在着邻苯二甲酸二异丁酯、邻苯二甲酸二(2-乙基)己酯、邻苯二甲酸二丁酯、9,12,15-三烯十八酸等多种预存抗菌物质;经Harpin或BTH诱抗剂诱导后,抗菌物质的种类和含量均显著增加;诱抗剂处理不仅可诱导甜瓜植株固有的抗菌物质如邻苯二甲酸二异丁酯、邻苯二甲酸二丁酯、1,3,5-环庚三烯、9,12,15-三烯十八酸等含量增加,而且可诱导合成新的棕榈酸、棕榈酸甲酯、9,12,16-三烯十八醛、邻苯二甲酸丁酯等多种可能的抗菌物质;Harpin或BTH诱抗剂限制了Erysiphe cichoracearum菌丝在叶片中的侵染,显著降低了甜瓜白粉病和霜霉病的田间病情指数。

The elicitor treatments of Harpin at 50 mg/L and BTH at 100 mg/L were used to study the effect on accumulation of antifungal compounds in muskmelon leaves during growth period. The compounds were extracted with methanol-dichlormethane and separated with thin layer chromatography （TLC）. Alter- nariaalternata was regarded as indicator fungal. Antifungal compounds distributed in inhibition zones were identified by gas chromatography and mass spectrum （GC-MS）. The results indicated that preformed anti- fungal compounds existed in leaves, such as bis （2-methylpr） 1,2-benzenecarboxylic acid, bis （2-ethylhex- yl） dioctyl ester, 1,2-benzenedicarboxylic acid, dibutyl ester, 1,2-benzenecarboxylic acid, methyl ester and 9,12,15-octadecatrienoic acid. The types and contents of antifungal compounds significantly were increased by elicitor treatments that induced not only original antifungal compounds but also novel ones. Both Harpin and BTH treatments restrained Erysiphe cichoracearum infecting leaves and significantly decreased disease indexes of powdery mildew and downy mildew in muskmelons.