摘要： 大豆炭腐病是大豆重要病害,高温、干旱的气候条件有利于病害的发生。本试验研究了引起大豆炭腐病病原菌菜豆壳球孢分离物的生物学特性。结果表明,该病原菌生长的温度范围为15～40℃,最适温度为35℃;pH范围为3～12,最适pH值为5;在含有120 mmol/L KClO3的PDA培养基上呈致密型生长类型。用蔗糖、PEG 6000和NaCl作为胁迫剂研究干旱胁迫对该病原菌生长影响,结果表明,一定浓度的蔗糖(100～500 mmol/L)、PEG 6000(10%～30%)和NaCl(100～300 mmol/L)均有利于病原菌菌丝生长;低水势环境对菌核的形态有一定的影响,且不利于菌核的产生。综合以上结果,大豆炭腐病病菌喜好高温、偏酸性和低湿环境。

关键词: 大豆炭腐病, 菜豆壳球孢, 生物学特性

Abstract: Soybean charcoal rot caused by Macrophomina phaseolina(Tassi) Goid causes heavy damage,and is generally considered to be enhanced by some combinations of heat stress and water deficit.The biological characteristic of M.phaseolina was studied in this study.The growth of mycelia preferred to 35℃and pH of 5,which could grow from 15℃ to 40℃,from pH value scale from 3 to 12 on PDA medium.When growing on a minimal medium containing 120 mmol/L potassium chlorate,the colonies of the tested isolates was dense,and showed these isolates were chlorate resistant genotype.The influence of osmotic potential on growth of the mycelia and morphology of microsclerotia in vitro was also studied using the PDA adjusted by sucrose,PEG 6000 and NaCl.The growth of the mycelia was promoted when the osmotic potential reduced caused by 100-500 mmol/L of sucrose,10%-30% of PEG 6000 and 100-300 mmol/L of NaCl.However,morphology of microsclerotia were affected at different osmotic potentials,and germination was drastically reduced with further reduction of osmotic potential.Results of this study showed that M.Phaseolina can grow quickly under the low acidic,high temperature and dry environment conditions.

Key words: Soybean charcoal rot, Macrophomina phaseolina, Biological characteristic

中图分类号: 

• S435.651