Development and Breeding of Herbicide‐Resistant Sorghum for Effective Cereal‐Legume Intercropping
Sanyuan Tang, Jiayang Shi, Xuefeng Li, Mingliang Yang, Chao Li, Dan Zhang, Sen Yang, Cuo Mei, Zuyong Luo, Lu Zhang, Wan‐Ke Zhang, Chunrui Zhang, Chen-Bo Zhu, Xianlin Ma, Ran Xia, Yuhang Chen, Jinsong Zhang, Qingshan Chen, Shouyi Chen, Qi Xie, Feifei Yu
Abstract
Weeds bring a serious challenge to crop production, and herbicides is the most effective and economic way to manage it in field. Sorghum is a critical crop for staple food, fodder, and biofuel. However, the lack of herbicide-resistant sorghum germplasm severely impedes its production. Here, we conducted a large-scale screening and identified 13 sorghum mutant lines resistant to imidazolinone (IMI) herbicides. Two unique mutation sites in SbALS (acetolactate synthase), thus namely Sbals-1 (A93T) and Sbals-2 (S624N) are discovered, both enhance sorghum tolerance to imazamox. Notably, under high concentrations of imazamox, sbals-1 presented a superior growth phenotype and elevated SbALS activity than sbals-2, a difference that can be attributed to the predicted protein structures. Breeding with Sbals, both grain- and grass-type sorghum, shows great weed control and field performance. The herbicide imazamox resistance is further evaluated in a soybean population for sorghum-soybean strip intercropping, identifying 123 highly resistant soybean varieties. Field intercropping tests indicated health growth of both soybean and sorghum lines post-imazamox treatment, which enhance field clearance of weed. This study, therefore, provides valuable insights not only for herbicide-resistant sorghum breeding but also for the successful implementation of efficient and sustainable cereal-legume intercropping systems.