啶酰菌胺与咪鲜胺复配对核盘菌的联合毒力测定

Combined virulence of boscalid and prochloraz to Sclerotinia sclerotiorum

为筛选防治向日葵菌核病的有效药剂,明确不同杀菌剂复配对核盘菌的联合毒力,测定了啶酰菌胺与咪鲜胺复配对核盘菌菌丝生长、菌核的萌发及生理代谢的影响。试验结果表明,不同比例啶·咪复配对核盘菌均有良好的抑制作用,二者复配比例为1:1时,增效系数为1.7657,增效作用最强;啶·咪复配能够有效抑制核盘菌的生长,降低菌核的萌发率和子囊盘形成率,其效果明显优于两单剂;啶·咪复配处理下,核盘菌草酸的分泌量和细胞壁降解酶的活性显著降低,核盘菌的Ss-oah1、Ss-pg1和Ss-pg3等3个致病相关基因的表达量与空白对照相比分别下调了69.90%、55.00%和71.30%。结果表明,啶酰菌胺与咪鲜胺复配,能有效抑制核盘菌的生长,降低核盘菌的致病力,是防治向日葵菌核病的有效复配药剂。

To clarify the combined virulence of fungicides for preventing Sclerotinia sclerotiorum infection on sunflower,we studied the efficacy of mixture of boscalid and prochloraz on suppression of mycelial growth,sclerotial germination and expression of pathogenesis-related genes in S.sclerotiorum.Results showed that the mixtures of the fungicides boscalid and prochloraz with different ratios had a demonstrable synergistic inhibition on S.sclerotiorum.When boscalid mixed prochloraz at ratio 1:1,the synergistic inhibition was the strongest with synergy ratio of1.7657.The mixture of boscalid and prochloraz could effectively inhibit the growth of S.sclerotiorum,reduce the germination rate of sclerotia.The formation rate of ascomycetes and its effect were significantly better than boscalid or prochloraz.The oxalic acid excreted by S.sclerotiorum and its activity of cell wall degrading enzymes were significantly reduced by treated with the mixture of boscalid and prochloraz.Compared with controls,the expression of 3pathogenic genes Ss-oah1,Ss-pg1 and Ss-pg3 of S.sclerotiorum were respectively reduced 69.90%,55.00%and71.30%.As a result,the mixture of boscalid and prochloraz could effectively inhibit S.sclerotiorum growth and reduce the pathogenicity of S.sclerotiorum.