利用异源六倍体(A^rA^rA^nA^nC^nC^n)与甘蓝种间杂交合成甘蓝型油菜的新方法

A new method of synthesizing Brassica napus by crossing B. oleracea with the allohexaploid derived from hybrid between B. napus and B. rapa

利用亲本种的遗传变异是改良油菜的重要途径,本研究提出一种利用甘蓝拓宽甘蓝型油菜遗传多样性的新方法。以甘蓝型油菜(AnAnCnCn)品种中双11号为母本,与白菜型油菜(ArAr)品系SWU07杂交,经染色体加倍获得异源六倍体(ArArAnAnCnCn),再与甘蓝(CoCo)杂交,创建出具有亲本种遗传成分的新型甘蓝型油菜(ArAnCnCo)。该六倍体连续3个世代核型稳定,各世代中的自交和自由授粉结实率无显著差异,花粉育性在94.6%～98.8%之间,3个世代自交平均结实率为每角果5.47粒,自由授粉平均结实率为每角果7.93粒;各世代六倍体(ArArAnAnCnCn)与不同类型甘蓝杂交平均结实率分别为每角果0.05、0.04、0.05粒,世代间无显著差异,且六倍体与栽培、野生甘蓝杂交结实性无显著差异,可交配性不受六倍体世代及甘蓝类型的影响。尽管该六倍体与甘蓝可交配性较低,但仍可在田间条件下成功杂交,获得新型甘蓝型油菜(ArAnCnCo),表明以ArArAnAnCnCn六倍体为桥梁与甘蓝杂交,是一种有效导入甘蓝遗传成分、创建新型甘蓝型油菜的新方法。

It is an important way to improve Brassica napus(A^nA^nC^nC^n)try using its parental species.Here a hexaploid method was proposed to synthesize B.napus by crossing B.oleracea(C^oC^o)with the hexaploid derived from the interspecific hybridization between B.napus and B.rapa.The hexaploid(A^rA^rA^nA^nC^nC^n)was developed by crossing B.napus cv.‘Zhongshuang 11’with B.rapa cv.‘SWU07’,and followed by chromosome doubling.And the hexaploid was crossed with various types of B.oleracea to develop new type B.napus.The hexaploid exhibited stable karyotype in three successive generations.There was no significant difference for seed setting rate between open-pollination and selfing-pollination in generations.The pollen fertility ranged from 94.6% to 98.8%.The average seed-setting rate was 5.47 and 7.93 seeds per pod for the open-pollination and selfing-pollination in three successive generations,respectively.The average crossability was 0.05,0.04,and 0.05 seeds per pod in three successive crossing generations between the hexaploid and B.oleracea,respectively.There was no significant difference in pod setting rate and seed setting rate among the hybrids between the hexaploid and the diverse types of B.oleracea.A few seeds were obtained by crossing B.oleracea with hexaploid A^rA^rA^nA^nC^nC^n in the field,suggesting that the method of hexaploid is use ful to introgress the genomic components of parental species into B.napus.