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

CLC Number: 

• S435.651