Preliminary Study on the Ethyl Methane Sulfonate Mutagenesis and Phenotypic Variation of Moringa oleifera Lam.

PurposeTo obtain the variety PKM-1 of Moringa oleifera Lam. with excellent traits and provide basic research materials to support the follow-up genetic improvement and breeding of M. oleifera, the ethyl methane sulfonate (EMS) mutagenesis was exploited to generate mutants.

MethodsSeeds of the PKM-1 from M. oleifera were subjected to be treated with five EMS mass fractions (0, 0.7%, 0.9%, 1.1%, and 1.3%) along with time periods 10 or 12 hours. The effects of EMS treatment on the seed emergence and seedling growth were analyzed, and the optimal combination for PKM-1 EMS mutagenesis was then determined, and the phenotypic variation characteristics of the mutagenesis in the offspring M₁ and M₂ were analyzed.

ResultsThe seedling emergence rate and relative seedling emergence rate of M. oleifera were extremely significantly reduced with EMS treatment (P<0.01). The higher the EMS mass fraction, the longer the initial germination time. The seeds emergence and the root growth of PKM-1 were both inhibited by EMS treatment. With the increase of EMS mass fraction, the root length gradually became shorter and the seedling height was either inhibited to some extent. The relative emergence rate and seedling formation rate of M. oleifera seeds treated with 1.1% EMS mass fraction for 10 hours were 58.60% and 57.07%, respectively, demonstrating the best mutagenesis effect. Furthermore, 700 M. oleifera seeds were treated by EMS mutagenesis. A total of 88 mutant materials of M₁ generation were obtained, with a mutation frequency of 33.33%; and 132 M₂ generation mutant materials were obtained, and the variation frequency was 43.14%. The genetic frequency of mutant traits among M₁-M₂ generation was 10.26%. The number of new mutant lines in M₂ generation was 68, and the variation frequency was 35.98%.

ConclusionThe optimal parameters for EMS mutagenesis of M. oleifera seeds were 1.1% EMS with 10 hours treatment. Nine phenotypic variation materials of M₁ and 11 phenotypic variation materials of M₂ were generated, which laid a foundation for obtaining stable genetic mutants of M. oleifera in the next M₃.