Selection of Hypo- and Hyper-tetraploid Seedlings from Abnormal Cotyledons Seedlings Obtained during Crossing of Tetraploid Grapes (Mtis Complexes)

摘要

We observed abnormal morphology of cotyledons occurring in seedlings derived from open-pollinated and cross-pollinated tetraploid grapes and selected aneuploids, especially hypo- and hyper-tefraploid in seedlings with abnormal morphology of cotyledons. Five types of morphologically abnonnal cotyledons were observed. In open-pollination of four tetraploid grapes, the frequency of abnormal cotyledons was 1.6% (49 of 3029 seeds). Percentage of aneuploids in the seedlings of abnormal cotyledons was 20.4%(10 of 49 seedlings). Aneuploids in open-pollination consisted of three (4n = 4x-2), four (4n = 4x-l), and three (4n = 4x+l) seedlings. In cross-pollination of tefraploids, the frequency of abnormal cotyledons was 3.4% (59 of 1729 seeds). Percentage ofaneuploids in the seedlings with abnormal cotyledons was 22.0%) (13 of 59 seedlings). Aneuploids from cross-pollination of tefraploids consisted of two (4n = 4x-2), nine (4n = 4x-l), one (4n = 4x+l), and one (4n = 4x+3) seedlings. According to the results, although the abnormal cotyledon morphology of seedlings obtained from crossing between tetraploid grapes appeared at low rate (2.3%), aneuploid seedlings occurred at high rate (22.0%o); therefore, it indicated that this selection sfrategy might be very efficient in the initial seedling stage.