Investigating genetic relationship of with via virtual allopolyploidy and hexaploidy strategy.

Unlabelled: is an important economic crop of the world; however, the narrow genetic base of this crop has tremendously decreased its crop productivity. As an ancestral species of , is of great importance in widening the genetic diversity of . In the present study, 42 SSR markers were employed to screen the genetic diversity among 83 , 16 , and other Brassica accessions. The molecular characteristics of 498 virtual lines were deduced based on the bands of and via a virtual allopolyploid strategy, and then compared with natural accessions. It was found that had rich genetic diversity and could be classified into four subgroups, of which subgroup B-III and subgroup B-IV exhibited the closest and the most distant genetic relationship with , respectively. To verify this, a hexaploidy strategy was applied to generated synthetic from 20 accessions, resulting in 45 new-type genotypes. The genetic analyses detected that synthetic derived from in subgroup B-III was close to natural , while synthesized with from subgroup B-IV exhibited wide genetic diversity and was most distant with current . This study revealed a great potential of in widening genetic diversity of particularly using in subgroup B-IV, and is helpful in better understanding of the genetic relationship between and .

Supplementary Information: The online version contains supplementary material available at 10.1007/s11032-020-01197-7.