Abstract:
The mutual dependance of Mj fertility and Ma mutations in rice was
studied after treatment with gamma rays and EMS. The frequency of chlorophyll
mutations increased with decrease in seed fertility when M, ears were selected
at random. However, at the lowest fertility class the mutation frequency was low.
This reduction is attributed to the elimination of mutants in the high sterility class.
The mutation yield can therefore be significantly enhanced by selecting M1 ears of
low fertility. The segregation ratio of mutants increased as fertility decreased.
Mutation spectrum was however not influenced by M1 fertility. This makes selection
for fertility quite ineffective in altering the mutation spectrum.