人参锈腐菌对人参根系分泌物中4种氨基酸的化学趋向性响应

Chemotaxis Response of Cylindrocarpon destructans to Four Amino Acids from Ginseng Root Exudates

为研究人参锈腐菌(Cylindrocarpon destructans)对人参根系分泌物中4种氨基酸的化学趋向性响应,采用平板法测定人参锈腐菌在3种趋化参数(浓度、pH、温度)下对4种氨基酸的化学趋向性响应;采用菌丝干重法和孢子萌发悬滴法测定优化趋化条件下的菌丝生长量和孢子萌发率。结果表明:人参锈腐菌对4种氨基酸的化学趋向性响应的优化培养温度为25℃;浓度和pH影响人参锈腐菌对4种氨基酸的化学趋向性响应,人参锈腐菌对低浓度(2.5 mg/L)的弱酸性(pH 6)丝氨酸以及中性(pH 7)缬氨酸、丙氨酸有最大化学趋向性响应,对中浓度(25 mg/L)的弱酸性(pH 6)苏氨酸有最大化学趋向性响应,趋化性指数(CMI)分别为1.1064,1.1175,1.3074,1.1127,孢子萌发率(SGR)分别为52.67%,56.67%,62.33%,68.67%,菌丝生长量(MG)分别为0.5422,0.5878,0.5700,0.5967 mg/mL。综上,人参锈腐菌对供试4种氨基酸具有化学趋向性响应,且在优化趋化条件下SGR和MG均有提高。

The chemotaxis response of C.destructans to four amino acids of ginseng root exudates was studied.Three chemotactic parameters(concentration,temperature,and pH)were determined by plate assay to study the chemotaxis response of C.destructans to four amino acids.The hyphae dry weight method and the spore germination hanging drop method were used to determine the mycelial growth and the spore germination rate under the optimized chemotactic conditions.The results showed that the optimized cultivation temperature of C.destructans chemotaxis response to four amino acids was all 25 o C.The chemotaxis response of C.destructans to four amino acids was differ⁃ent under conditions of different concentration and pH value.The chemotaxis response reached the highest under the weak acid(pH 6)serine and neutral(pH 7)valine and alanine at low concentration(2.5 mg/L),while weak acid(pH 6)threonine at medium concentration(25 mg/L),the date of chemotactic migration index(CMI)was 1.1064,1.1175,1.3074 and 1.1127 and spore germination rate(SGR)was 52.67%,56.67%,62.33%and 68.67%,and mycelial growth(MG)was 0.5422,0.5878,0.5700 and 0.5967 mg/L.The C.destructans showed that Cylindrocarpon destructans exhibits a che⁃motaxis responses to the four amino acids tested,and both SGR and MG are improved under the opti⁃mized chemotactic conditions.