Broadening the genetic base of Brassica juncea by introducing genomic components from B. rapa and B. nigra via digenomic allohexaploid bridging
Jiaqin Mei,
Jin Liu,
Fang Yue,
Yangui Chen,
Jiayi Ming,
Zhiyong Xiong,
Fengqun Yu,
Jiana Li,
Wei Qian
Affiliations
Jiaqin Mei
College of Agronomy and Biotechnology, Southwest University, Chongqing 400716, China; Academy of Agricultural Sciences, Southwest University, Chongqing 400716, China; State Cultivation Base of Crop Stress Biology for Southern Mountainous Land of Southwest University, Chongqing 400715, China
Jin Liu
College of Agronomy and Biotechnology, Southwest University, Chongqing 400716, China; Academy of Agricultural Sciences, Southwest University, Chongqing 400716, China; State Cultivation Base of Crop Stress Biology for Southern Mountainous Land of Southwest University, Chongqing 400715, China
Fang Yue
College of Agronomy and Biotechnology, Southwest University, Chongqing 400716, China; Academy of Agricultural Sciences, Southwest University, Chongqing 400716, China; State Cultivation Base of Crop Stress Biology for Southern Mountainous Land of Southwest University, Chongqing 400715, China
Yangui Chen
College of Agronomy and Biotechnology, Southwest University, Chongqing 400716, China; Academy of Agricultural Sciences, Southwest University, Chongqing 400716, China; State Cultivation Base of Crop Stress Biology for Southern Mountainous Land of Southwest University, Chongqing 400715, China
Jiayi Ming
College of Agronomy and Biotechnology, Southwest University, Chongqing 400716, China; Academy of Agricultural Sciences, Southwest University, Chongqing 400716, China; State Cultivation Base of Crop Stress Biology for Southern Mountainous Land of Southwest University, Chongqing 400715, China
Zhiyong Xiong
Key Laboratory of Herbage and Endemic Crop Biotechnology, School of Life Sciences, Inner Mongolia University, Hohhot 010070, Inner Mongolia, China
Fengqun Yu
Agriculture and Agri-Food Canada, Saskatoon Research and Development Center, 107 Science Place, Saskatoon, SK S7N 0X2, Canada
Jiana Li
College of Agronomy and Biotechnology, Southwest University, Chongqing 400716, China; Academy of Agricultural Sciences, Southwest University, Chongqing 400716, China; State Cultivation Base of Crop Stress Biology for Southern Mountainous Land of Southwest University, Chongqing 400715, China
Wei Qian
College of Agronomy and Biotechnology, Southwest University, Chongqing 400716, China; Academy of Agricultural Sciences, Southwest University, Chongqing 400716, China; State Cultivation Base of Crop Stress Biology for Southern Mountainous Land of Southwest University, Chongqing 400715, China; Corresponding author.
A narrow genetic base has hindered improvement of Brassica juncea (AjAjBjBj). In this study, large-scale genomic components were introduced from diploid ancestor species into modern B. juncea using a digenomic hexaploid strategy. The hexaploids AjAjArArBjBj and AjAjBjBjBnBn were first developed from B. juncea × B. rapa (ArAr) and B. juncea × B. nigra (BnBn), and then crossed with dozens of B. nigra and B. rapa, respectively. Both types of hexaploid showed high pollen fertility and moderate seed set throughout the S1 to S3 generations, and could be crossed with diploid progenitor species under field conditions, in particular for the combination of AjAjBjBjBnBn × B. rapa. Thirty AjArBnBj-type and 31 AjArBnBj-type B. juncea resources were generated, of which the AjArBnBj type showed higher fertility. Of these new-type B. juncea resources, 97 individual plants were genotyped with 42 simple sequence repeat markers, together with 16 current B. juncea accessions and 30 hexaploid plants. Based on 180 polymorphic loci, the new-type B. juncea resources and current B. juncea were separated clearly into distinct groups, with large genetic distance between the new-type B. juncea resources and current B. juncea. Our study provides a novel approach to introducing large-scale genomic components from diploid ancestor species into B. juncea.
