Aneuploid Production from Crosses with Diploid and Triploid in Apple Tree
2009
Zhang, C.H. (Kangwon National University, Chuncheon, Republic of Korea) | Park, S.M. (Kangwon National University, Chuncheon, Republic of Korea), E-mail: [email protected]
The occurrence frequency of aneuploid seedlings in progenies of open pollinated apple triploid, 3x × 2x, 2x × 3x, and 3x × 3x crosses was investigated, and their potentials for genetic studies and breeding were evaluated. The results showed that in the cross combination of open pollinated triploid, 2x × 3x, 3x × 2x, and 3x × 3x, somatic chromosome numbers of the 242 seedlings ranged from 34 to 68. The aneuploid seedlings having chromosome numbers from 36 to 43 appeared with high frequencies, and the seedlings having 38 chromosomes showed the highest frequency. Of these seedlings, four single trisomic seedlings (2n = 2x + 1 = 35) were detected. Three of the 242 seedlings with 54 (3x + 3), 55 (3x + 4), and 68 (4x) chromosomes were considered to have originated from the unreduced gametes (2x + 3, 2x + 4, and 3x) of triploids. Embryos obtained from open pollinated triploid were a little lighter than those of open pollinated diploids. The embryos which were lower than 15 mg did not germinate, due to their abortion. The leaf size of aneuploid seedlings was especially small. Triploid is a valuable material for producing aneuploids, and aneuploid has great potentials on cytogenetic and genetic studies in apple breeding because of its special characteristics.
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