Abstract: Three cucumber inbred lines with different types of bitterness (foliage and f ruit are all bitter : BiBiBtBt , only foliage is bitter : BiBibtbt , foliage and fruit are not bitter : bibibtbt) were used as materials in the experiment , the separate ratios of phenotype in their descendant s were investigated. The results showed that the gene Bi and bi which cont rolled foliage bitterness was independent of Bt and bt which cont rolled fruit bitterness. The homogeneous gene bi was recessive epistatic to the gene Bt . The fruits were also bitter when the gene Bi and bi was heterozygous even in the absence of Bt , but the extent of bitterness is lighter than that caused by the gene Bt and the proportion of bitter fruit was lower.

Key words: Cucumber, Bitterness, Inheritance