STUDY ON THE EMBRYOGENESIS OF CROSSES OF TETRAPLOID WITH DIPLOID IN CUCUMBER

To investigate the reasons behind the seeding difficulty, pollination and embryonic developments of cucumber from crosses of autotetraploid with diploid (4x×4x, 2x×2x, 4x×2x, 2x×4x) were studied.
Results showed: 1) pollen germination rate on the stigma of self-pollinated tetraploid (4x×4x) were the lowest, and in 2x×2x, 2x×4x, the percentage of pollen germination on stigma were higher; 2) tetraploid plant have a higher abnormal embryo sacs rate (from 17.0s to 24.90%) than that of diploid (from 4.8 to 6.5%); 3) the fertilization process of self-pollinated diploid, self-pollinated tetraploid, crosses of tetraploid with diploid (4x×2x) were from 24 to 36 h, from 48 to 60 h, from 36 to 48 h respectively.
No fertilization was observed in crosses of diploid with tetraploid (2X×4X). The fertilization rates of self-pollinated tetraploid were lower (19.17 to 25.39%) than that of 4x×2x (30.25 to 48.08%); 4). The embryo developments of self-pollinated diploid and tetraploid were normal, whereas in 4x×2x, the embryo development was abnormal and developed very slowly, which were the key reason of sterility.
Therefore, no mature triploid seeds have been obtained; and 5) In 4x×2x, the obvious degeneration of the endosperm was the important factor of the slow embryo development.

IV International Symposium on Cucurbits

Yike Han, Shengli Du, Shuming Wu, Cuihong Hu, Aimin Wei, Guihua Zhang, Nan Liu

cucumber, tetraploid, fertilization, embryogenesis

https://doi.org/10.17660/ActaHortic.2010.871.77