大鸭梨与苹果梨F_1代染色体数目鉴定

Observation on Chromosome Number of F_1 Generation from Pear Cultivars 'Dayali' × 'Pingguoli'

用去壁低渗法对大鸭梨与苹果梨Ｆ１代１６个单株的染色体数目进行了鉴定。结果发现，４个单株为四倍体（２ｎ＝４ｘ＝６８），占观察总数的２５％；１０个单株为三倍体（２ｎ＝３ｘ＝５１），占观察总数的６２．５％；１个单株为二倍体（２ｎ＝２ｘ＝３４）；１个单株为非整倍体。多倍体出现率为８７．５％，表明大鸭梨与苹果梨杂交组合在多倍体育种中具有特殊价值。

Observations on chromosome number of 16 seedlings derived from pear cultivars 'Dayali' x 'Pingguoli' were made by Removal of Cell Wall and Hypotonic method and it was found that 4 seedlings, 25 % of the total seedlings, were tetraploid (2 n=4 x = 68); 10 seedlings,62. 5 % of the total seedlings,were triploid (2 n = 3 x = 51 ); 1 seedling was diploid (2 n = 2 x = 34); I seedling was aneuploid. The ratio of polyploid produced was 87. 5 %,which has shown that crossing combination between Dayali and Pingguoli has special value in pear polyploid breeding.