Taking dry seeds of bitter gourd inbred line‘ Jiangmendading’ as materials，setting up
combinations of treatments with different EMS concentrations（ 0，0.3%，0.6%，0.9%，1.2% and 1.5%） and
different mutagenesis times（2，4，6 hours），this study determined the suitable conditions for EMS mutagenesis of
bitter gourd seed through statistical data of seed germination vigor and rate and observation on M₀ plant phenotypes．
Results showed that EMS concentration，mutagenesis time and their interaction had significant impact on
germination vigor and rate of bitter gourd seed．According to the principles of semi-lethal condition，8 hours of
soaking with water followed by 2 hours with 1.5% or 1.2% EMS treatment were the suitable conditions for EMS
mutagenesis of bitter gourd seed．Field planting and phenotype observation of 129 M₀ plants after 2 hours with
1.2% or 1.5% EMS treatment revealed that the mutation frequency of bitter gourd plant phenotypes were 5.12% and
7.85%，respectively，and the phenotypic variations often occurred in leaf and fruit，indicating that the selected
conditions were suitable for studying EMS mutagenesis of bitter gourd seed．These results have laid a foundation for
further using EMS mutagenesis technology to construct mutant library and create new bitter gourd materials．