番茄早疫病菌抗啶酰菌胺菌株细胞膜透性变化

为探究番茄早疫病菌Alternaria solani对啶酰菌胺产生抗性后膜透性的变化,采用菌丝生长法、可见分光光度法、电导率法和荧光猝灭法分别测定了抗、感菌株对NaCl渗透压的敏感性、胞内可溶性蛋白和糖的含量、膜渗透率及对啶酰菌胺的吸收量。结果表明:抗性(R-Bos)菌株在2.5 g/L NaCl浓度中生长最快,敏感(S-Bos)菌株则在5 g/L NaCl浓度中生长最快;在0~10 g/L NaCl浓度下,R-Bos菌株的生长明显快于S-Bos菌株,在20~80 g/L NaCl浓度下生长无显著差异;R-Bos菌株的可溶性蛋白和可溶性糖含量显著增高,分别达61.9%~105.2%和133.1%~161.9%;用啶酰菌胺处理菌株后,所有菌株的渗透率上升,膜透性增大,但R-Bos菌株的渗透率始终低于S-Bos菌株;且R-Bos菌株对啶酰菌胺的吸收量明显减少,为48.3%~49.9%。推测番茄早疫病菌对啶酰菌胺产生抗性后,胞内保水能力提高,对渗透压表现出耐受性,同时膜透性降低使得对药剂的吸收能力下降。

Variation of cell membrane permeability of early blight pathogen Alternaria solani resistant to boscalid

To explore the variation of cell membrane permeability when early blight pathogen Alternaria solani developed the resistance to boscalid, the sensitivity to osmotic pressure of NaCl, the contents of soluble protein and soluble sugar in the cell, the penetrance of membrane, and the absorption of boscalidresistant strains (R-Bos) and boscalid-sensitive ones (S-Bos) were determined with the methods of mycelial growth, visible spectrophotometry, electrical conductivity, and fluorescence quenching. The results showed R-Bos and S-Bos strains grew fastest at concentration of 2.5 g/L and 5 g/L NaCl, respectively. R-Bos strains grew faster than S-Bos strains from 0 to 10 g/L NaCl concentration, and there was no difference between them from 20 g/L to 80 g/L NaCl concentration. The contents of soluble protein and soluble sugar in R-Bos strains were higher than those in S-Bos ones, which increased to 61.9%-105.2% and 133.1%-161.9%, respectively. The permeability of all strains rose after the treatment of boscalid. But the permeability of R-Bos strains was always lower than S-Bos one. R-Bos strain absorption boscalid lower and then declined to 48.3%-49.9%. Therefore, it was speculated that when A. solani became resistant against boscalid, the high water retention capacity could make the resistant pathogen endure the osmotic pressure, and the low membrane permeability might lead to the boscalid was absorbed less.