Gynoecy in cucumber is govern of single dominant gene. If we cross homozygous gynoecious inbred line with monoecious line we will get F1 progeny as gynoecious. Further there will be segregation in the ratio 3:1 (gynoecy:monecy) in F2 generation.

Thank you. Dr. Pratap sir.

                                            Im targeting both the characters (gynoecious and parthenocarpy). what may be the F1 progeny.

Refer to this article to know the inheritance of gynoecious and parthenocarpy.

ACTA HORTICULTURAE SINICA 2008, Vol. 35 Issue (10): 1441-1446

Inheritance of Parthenocarpy in Gynoecious Cucumber (Cucumis Sativus L.)

For the results of producing hybrid from Gynoecious x Monoecious:

1. Please refer to the attached article of hybrid cucumber breeding (on page 4). It introduces 4 types of hybrid productions: Gynoecious x Monoecious hybrids, Gynoecious x Gynoecious hybrids, Gynoecious x Hermaphroditic hybrids, and Gynoecious x Andromonoecious hybrids.

2. It says: seed from Gynoecious x Monoecious of hybrid usually is blended with seed from a monoecious cultivar added in a proportion of about 10%. 

For the inheritance of parthenocarpy:

1. It was first reported in 1969 by Peterson (see attachment):

"The inheritance of parthenocarpy in cucumber is conditioned by an incomplete dominant gene P. In the homozygous condition PP produces parthenocarpic fruits early, with the first developing generally by the fifth node. Heterozygous Pp plants produce parthenocarpic fruits later than homozygous plants and fewer in number. The homozygous recessive pp produces no parthenocarpic fruits."  [ http://link.springer.com/article/10.1007%2FBF00021987 ]

2. In the attached second paper (Japan group), it confirmed the earlier report. The 'parthenocarpy' trait is governed by an Incomplete dominant gene P. (see attached paper, p. 175-176].

3. So, from these results, you can predict parthenocarpic trait in your hybrid.

  Dr. Yuan-Yeu Yau. Thank You for your suggestions.

Dear Bommesh if u will made cross between gynoecious parthenocarpic inbred lines with monoecious non parthenocarpic inbred lines the resulting F1 progeny plants will be sub-gynoecious (means staminate flowers will be their in some plants but pistillate flowers are more thn the staminate and such kind of plants we include in gynoecious category) as well as pure gynoecious plants. Upon selfing of F1 plants these will segerate in 3:1 (3 pure gynoecious and subgynoecious: 1 monoecious plants). Therefore this ratio suggests that gynoey in cucumber is under the control of single dominant gene.

Thank you, Gograj Jat