水稲品種しまねにしきに生じた変異体について

In 1976 many rice plants bearing a mutant character, "brittle culm" were found in the population of rice variety "Shimanenishiki", grown on the seed farms in Shimane Prefecture.
The culms and leaves of this mutant were very brittle or fragile, and were easily breakable between fingers. No other morphological characters differed from the common variety, except the drooping flag leaf.
The cross experiments between the mutant and the common variety showed that F_1 was normal and F_2 segregated into two classes of phenotype, normal and brittle, which is close to monogenic segregation of 3 : 1.
The results indicate that the present mutant character, "brittleness", behaves as single recessive to the normal tough culm character.