Abstract:

Using the model of the major gene plus polygene of quantitative traits, a joint analysis of multi-generations from crossing a highly parthenocarpic gynoecious lines‘6401’with two non-parthenocarpic inbred lines‘6429’and‘6426’was carried out to investigate the inheritance of the parthenocarpy in cucumber. Results showed that the inheritance of parthenocarpy in gynoecious cucumbers with different genetic backgrounds was fitted into the same genetic model. Inheritance of parthenocarpy is expressed as incompletely recessive, fit the E-1-1 model, and controlled by two additive-dominant-epistatic major genes and additive-dominant polygenes. Dominant effect of the first major gene and dominant × dominant interaction between the two major genes as well as polygene effects were higher in those two cross combinations. The heritabilities of B₁、B₂、F₂ from cross ‘6401×6429’were 51.36%, 72.31% and 76.78% , respectively, while the heritabilities of B₁、B₂、F₂ from ‘6401×6426’were 20.50%, 75.39% and 74.58% respectively. These results indicated that breeding of gynoecious cucumber with highly parthenocarpy should choose parents that both are highly parthenocarpy.

Key words: cucumber, gynoecious, parthenocarpy, inheritance