Ethyl Methanesulfonate 處理에 依한 벼의 分蘖別突然變異率 및 分離比

Chlorophyll Mutation Rate and Segregation Ratio of Tillers after the Treatment of Rice Seed with Ethyl Methanesulfonate

In order to examine whether there exist any differences in mutation rate and segregation ratio among the tillers, rice seeds were treated with EMS and sown directly on the beds inducing the full growth of lower tillers which are liable to perish when transplanted. There were no regularities or tendencies in mutation rate and segregation ratio among the tillers in the order of main culm, lower primary tillers, upper primary tillers and secondary tillers as was expected when the mutation rate and segregations ratio are considered based on the number of initial cells in the shoot primordia of the mature seed embryo. Some workers, based on the M₂ segregation ratio of mutagen-treated cereal crops, contend that main calms have more initial cells of four or so while the upper primary tillers have one cell, resulting in certain definite tendencies in mutation rate and M₂ segregation ratio in the tiller system. Present results are contradictory with the above-mantioned hypothesis.