甜菜属近缘种三种间杂种及其后代减数分裂行为观察

本文观察了岔根甜菜(Beta Patula Ait)、叶用甜菜(B.cicla)及普通甜菜(B.vulgaris)三种间杂种的F_1、F_2及F_3的减数分裂行为。各代减数分裂终变期,染色体联会成9个二价体。中期Ⅰ有棒状结合,也有环状结合。F_1、F_2、F_3各代中期出现单价体频率分别为0.23、0.18、1.13。后期Ⅰ出现染色体桥、落后等异常现象,各代频率分别为0.93、2.2和3.26。后期Ⅱ各代异常频率为0.41、0.75和0.32。异常四分体频率各代分别为0.16、0.13和0.66。异常频率有随世代增长而增加的趋势。结果表明,B.patula、B.cicla及B.vulgaris三个种的染色体组基本上是同源的。本文还讨论了杂种减数分裂稳定性及遗传育种上利用的可能性。

Meiosis Behavioural Observation on the Interspecific Hybrids and Their Progenies among Three Close Relational Species of the Genus Beta

The behaviour of meiotic division in F1, F2 and F3 of interspecific hybrids among Beta patula Ait.(2n=18) , B. cicl L. (2n=18) and B. vulgaris L. (2n=18) was observed by this paper. During diakinesis, the chromosomes synapsed to become nine bivalents in all generations, During 1st metaphase (MI) , it showed as bars and ring chromosomes. It appeared mouovalent rates 0.23, 0.18 and 1.13 in F1, F2 and F3 generations respectively. During 1st anaphase (AI) , it showed to be abnormal phenomena such as chromosome bridges , lagging etc, their rates were 0,91, 2.2 and 3.26 in all generations respectively. During 2nd anaphase (A II ) , abnormal rates showed to be 0.41 0.75 and 0.32 respectively. Abnormal tetrad rates in different generations were 0.16, 0.13 and 0.36 respectively. Abnormal rates tend to increase with the transfer from gene tion. to generation. The results showed that the genome; of B.patula, B.cicla and B. vulgaris were almost homologous. The meiosis stability of the hybrids and availability of application ia the genetic and breeding were discussed in this paper.