The study of triploid progenies crossed between different ploidy grapes
The cross between different ploidy grape was one of the effective ways to obtain new seedless cultivars, in this study, through testing the changes of the ovule weight and observing its anatomical structure, the period and mode of ovule abortion in crosses between diploid and tetraploid grape cultivars were studied, reciprocal cross was also conducted between them, the results indicated that the proper sampling period is one of the most important factors of the grape in ovule culture, unlike the seedless cultivars, the embryo abortion did not occur at the same time for most seeded cultivars crossed with different ploidy plants, the ovule abortion was only individual behavior. The period of ovule abortion was correlated with the mature period of the female parent. The abortive embryo of early-maturing cultivars occurred at five weeks after pollination, then the mid-maturing ones and latematuring ones were at six and nine weeks after pollination comparatively. The reciprocal crossing results showed that this crossing form has great mating obstruction and the situation was more serious when tetraploid cultivars were used as female parent. Few seeds from 2X×4X had good germinability, while those from 4X×2X had lost their germinability and no seedlings were obtained, the highest germination rate and seedling survivals rate were obtained when the ovule was excised 60 days after pollination, it is easier to harvest hybrid progeny when using diploid as female parent.
Key words: Vitis vinifera, ovule culture, hybridization, polyploidy, reciprocal cross.