MUTATION FREQUENCIES IN BARLEY AFTER METHYL METHANESULFONATE TREATMENTS

Abstract

Spike mutation frequencies induced in barley embryos by treatment of grains with methyl methanesulfonate (MMS) and ethyl methanesulfonate (EMS) solutions were determined. M2 seedlings were scored for chlorophyll-deficient mutations. When 0.024[image] MMS solutions were applied for 2-4 hr. spike-mutations frequencies of 12 - 31% were obtained in greenhouse-grown M1 plants. In field-grown plants the highest spike-mutation frequency observed was 22%. It was concluded that favorable germination and seedling-growth conditions must be provided for the recovery of high frequencies of mutated spikes. Equimolar solution (.024[image]) of EMS and MMS applied for 2 hr. induced spike mutations at rates of 4.2% and 12.4% respectively. Possible reasons for this difference in effects are discussed.