7种杀菌剂对姜瘟病菌Z-AQ-2菌株的抑菌活性

青枯菌4号生理小种引起的姜瘟病是我国生姜生产上的巨大障碍。本研究以分离自5种不同寄主的8株青枯菌为研究对象,采用最小抑制浓度法(MIC)评价了它们的铜抗性水平,发现分离于山东安丘的4号小种Z-AQ-2菌株的铜抗性水平最高,为1.6mmol/L;采用生长速率法测定了7种常用杀菌剂对Z-AQ-2菌株的室内毒力,结果表明:3%中生菌素可湿性粉剂对姜瘟病菌的抑菌活性最高,其EC50为5.2mg/L,其次为6%寡糖·链蛋白可湿性粉剂,EC50为21.2mg/L,20%叶枯唑可湿性粉剂在3种不含铜的农药中EC50值最高,为58.7mg/L,4种铜制剂抑菌效果相对较差,EC50为51.5~148.7mg/L;进一步采用Colby法评价了叶枯唑与氢氧化铜、叶枯唑与中生菌素以及中生菌素与氨基寡糖素的混用效果,结果表明:三组药剂的混用均可产生增效或加成效果。

Antibacterial activity of seven bactericides to Ralstonia solanacearum strain Z-AQ-2

Bacterial wilt of edible ginger caused by Ralstonia solanacearum race 4 is a severe threat to the production of ginger. Eight R.solanacearum strains isolated from 5 plant species were selected to investigate their copper resistance phenotype. The results showed that the strain Z-AQ-2 of R. solanacearum race 4 had the highest resistance to copper compounds, with the MIC value of 1.6 mmol/L. The study also examined the bacteriostatic activity of seven bactericides commonly used in the field. The results showed that 3% zhongshengmycin WP had the highest inhibition rates among the seven bactericides, with the EC50 value of 5.2 mg/L, followed by 6% oligosaccharins WP and 20% bismerthiazol WP, with the EC50 values of 21.2 mg/L and 58.7 mg/L, respectively. We evaluated the bacteriostatic activity of bismerthiazol plus copper hydroxide, bismerthiazol plus zhongshengmycin, and oligosaccharins plus zhongshengmycin by the method of Colby and the results showed that all the three mixtures had good synergism effect.