埃塞俄比亚芥与诸葛菜属间杂种的基因组原位杂交分析

Genomic Analysis of Intergeneric Hybrids between Brassica carinata and Orychophragmus violaceus by Using in Situ Hybridization

用幼胚培养方法重新获得的埃塞俄比亚芥BrassicacarinataA.Braun,2n=34与诸葛菜Orychophragmusviolaceus L.O.E.Schulz,2n=24的属间杂种仍为混倍体2n=14～34,2n=34细胞的频率最高;绝大多数花粉母细胞PMCs表现正常的17个二价体配对和17∶17的分离.基因组原位杂交分析结果表明,在所有体细胞和PMCs中不含有整条的诸葛菜染色体,2n=34的体细胞和PMCs中包含了来自黑芥B.nigra L.Koch,2n=16的16条染色体.这些具有完全或部分埃塞俄比亚芥染色体组成的细胞,可能来源于以前提出的杂种细胞在有丝分裂中完全或部分亲本染色体组分开和染色体复制,并伴随诸葛菜染色体的消除.

Intergeneric hybrids between Brassica carinata (2n=34, BBCC),regenerated with embryo rescue and Orychophragmus violaceus (L.) O.E. Shchulz (2n=24, OO) were still mixoploids (2n=14～34) of which the ones of 2n=34 occurred most frequently. Most pollen mother cells had 17 bivalents at diakinesis and showed 17∶17 segregation at anaphase Ⅰ. The genomic analysis by in situ hybridization revealed that all the ovary cells and pollen mother cells did not contained any intact chromosomes of Orychophragmus violaceus and the somatic cells and pollen mother cells of 2n=34 carried 16 chromosomes of B. nigra (L.) Koch (2=16). The cells carrying complete and partial genome of Brassica carinata probably originated from the separation and reproduction of complete or partial parental genome of formerly proposed hybrid cells in mitosis in connection with the elimination of Orychophragmus violaceus chromosomes. The results of the study provided the evidences to the phenomenon of parental genome separation.