Development of EMS Mutagenized Wheat Mutant Lines Resistant to Fusarium Crown Rot and Fusarium Head Blight

Abstract Plant breeding relies on genetic variation to produce new and improved cultivars. One way to obtain novel traits is by inducing mutations. The present study aimed to create a Fusarium crown rot (FCR) and Fusarium head blight (FHB)-resistant mutagenized wheat population using ethyl methane sulphonate (EMS) and identify mutant resistance to FCR and FHB, which could provide a starting point for resistance breeding. The optimal mutagenesis conditions were determined based on the germination percentage. This study used six Chinese wheat cultivars, namely Jimai22, Hengguan35, Shixin828, Gaoyou2018, Keiwei20, and Keiwei18, to create a mutant population by treating them with EMS. For Shixin828, the optimal condition was 0.8% EMS with a 50-55% germination rate. For Hengguan35 and Jimai22, it was 0.6% EMS. For Gaoyou2018 and Kewei20, it was 0.8% and 0.4-0.6%, respectively. The FCR disease index of the mutant lines (M1) ranged from 10.00 to 77.67. For M2, the number of individual mutant plants demonstrating resistance to FCR varied from 76 to 102. In M3, 570 healthy plants were obtained using various EMS concentrations. The mutant line Kewei18 demonstrated the most resistance to FCR, FHB, and Deoxynivalenol (DON) infection. Kewei20 mutants had a higher FHB susceptibility than other mutants. Overall, mutants from the Kewei18 genetic background displayed better disease resistance to both diseases and DON contamination than natural plants. Mutants with or moderate resistance to FCR and FHB could be used in breeding and genetic studies to identify FHB and FCR-resistant Quantitative Trait Locus (QTL) in wheat.