乌头酸对尖孢镰刀菌百合专化型抑制作用分析

乌头酸是兰州百合一种重要的根系分泌物，为探究乌头酸对尖孢镰刀菌（Fusarium oxysporum）百合专化型的作用效果，测定外源乌头酸对F.oxysporum生长及抗氧化酶活性基因表达量的影响。结果表明，浓度为1.175~1 175 mg·L^-1时，乌头酸对F.oxysporum的生长具有抑制作用，且随着浓度增加，抑菌作用显著。浓度为1 175 mg·L^-1时，与CK相比，乌头酸对F.oxysporum抑菌率、产孢量抑制率和孢子萌发抑制率分别达到91.95%、77%、93%。乌头酸处理引起菌丝体电导率增大，随着浓度和时间的增加，SOD、POD活性呈现先增加后降低的趋势。SOD酶合成基因在转录水平上于11.75~1 175 mg·L^-1处理下调表达， 1.175 mg·L^-1处理时SOD酶合成基因出现上调，与CK差异不显著。POD酶合成基因在转录水平上所有处理均下调表达。可见，乌头酸可以作为化感抑制剂应用于植物土传病害的防治。

Analysis of Inhibitory Effect of Aconitic Acid against Fusarium oxysporum f.sp.lilii

Aconitic acid is an important root exudate from Lanzhou lily.In order to explore the effect of aconitic acid on Fusarium oxysporum f.sp.lilii, the growth of F.oxysporum and the genes expression of its antioxidant enzyme activity were determined in this study.The results showed that aconitic acid significantly inhibited the fungal growth under concentration range of 1.175-1 175 mg·L^-1,and with increase of concentration,the antifungal effect was significant.Compared with CK,at 1 175 mg·L^-1 concentration level,the inhibition rate of hyphae,spore production,and the spore germination reached 91.95%,77% and 93%,respectively.In addition,mycelial conductivity increased under aconitic acid treatment.With the increase of concentration and time,the activities of SOD and POD showed rising trend at first and then falling treand.The SOD enzyme synthesis gene expression was down-regulated under 11.75-1 175 mg·L^-1 treatments,and SOD enzyme synthesis gene was up-regulated under 1.175 mg·L^-1 treatment,there was no significant differences compared with CK,Moreover,the POD enzyme synthesis gene was down-regulated under all above treatments.The results suggested that aconitic acid should be used as an allelopathic inhibitor to control soil-borne diseases.