辣椒疫霉对双炔酰菌胺抗药性生理生化机制研究

Study on Physiological and Biochemical Resistance Mechanism of Phytophthora capsici to Mandipropamid

本试验对辣椒疫霉亲本菌株和抗性菌株的生理生化指标进行了测定,初步研究了辣椒疫霉对双炔酰菌胺产生抗性的机制。结果表明:辣椒疫霉亲本菌株和抗性菌株的菌丝生长受NaC l和葡萄糖影响较小,且NaC l和葡萄糖不同浓度处理后的所有菌株之间渗透压也均不存在显著性差异,故得知NaC l和葡萄糖均不能为疫霉菌提供营养和抑制其渗透。双炔酰菌胺低浓度处理能够使抗性菌株菌体内渗漏出较多的内含物,但随着处理时间的延长和浓度的提高内含物渗漏反而减少;亲本菌株和抗性菌株菌体内可溶性蛋白含量和β-1,3葡-聚糖酶的活力差异显著:亲本菌株菌体内的可溶性蛋白含量和β-1,3葡-聚糖酶的活力均高于抗性菌株。随着双炔酰菌胺处理时间的延长,亲本菌株和抗性菌株的可溶性蛋白含量和β-1,3葡-聚糖酶的活力都呈下降趋势。由此得出:辣椒疫霉内含物通过细胞膜外渗,致使药液在菌体内的积累减少,最终使到达作用靶标药剂的实际浓度下降;同时菌体的可溶性蛋白含量降低、β-1,3葡-聚糖酶的活力下降可能是对双炔酰菌胺产生抗性的原因。

In order to study on resistance mechanism of P.capsici isolates with parental and resistant to the mandipropamid,determined on physiological and biochemical indexes were done.The results indicated that in the NaCl and glucose concentrations,isolates with parental and resistant for mycelial growth capacity was less affected,and at different concentrations,all strains show no significant osmotic pressure difference.It can be drawn NaCl and glucose on capsici does not have to provide nutritional and osmotic inhibition.Although mandipropamid in low concentrations resistant strains in vivo electrolyte to leak out more,with the treated time and concentration increase,the resistant strains inclusions less leakage.At the same time strains with parental and resistant that soluble protein content and β-1,3-glucanase activity change,parental strains of soluble protein content and cell β-1,3-glucanase activity is higher than resistant strains.With the treated time increase,all strains of the soluble protein content and β-1,3-glucanase activity tended to decrease.It can conclude that the inclusion of P.capsici is leakage through the cell membrane to accelerate metabolism,reduce the accumulation of mandipropamid,so that reach the actual target concentration was decreased.At the same time the body of the soluble protein content and β-1,3-glucanase activity decreased.For these reasons may be resistant mechanism to mandipropamid.