Superior rice variety YJ144 with improved rice blast resistance, yield, and quality achieved using molecular design and multiple breeding strategies.

Unlabelled: Yanfeng 47 (YF47) is an elite rice variety cultivated in China on nearly 2 million hectares over the past 20 years. However, YF47 is highly susceptible to rice blast (), one of the most destructive rice diseases. In this study, we developed novel TPAP (tetra-primer ARMS-PCR) functional markers for the genes , , and , all of which afford broad-spectrum resistance to blast. A collection of 91 rice germplasms with similar ecological characteristics to YF47 were screened, and Wuyunjing 27 (WYJ27) with and alleles and P135 with the allele were identified. Furthermore, the corresponding positive , , and alleles were transferred into YF47 using single, mutual, and backcrosses, together with molecular marker-assisted selection (MAS) and anther culture technology. These genetic materials, carrying one, two, or three functional alleles, were generated within 3 years, and compared to YF47, they all showed improved resistance to naturally inoculated rice blast. Further improved lines (IL) 1 to 5 (all containing , , and alleles) were evaluated for yield performance, and when no fungicide was applied, all lines except IL-4 showed increased traits compared with those of YF47. IL-5, renamed Yanjing 144 (YJ144), showed yield increases in the Liaoning province regional variety comparison test and superior appearance quality compared to YF47. Our work provides a molecular design strategy for pyramiding multiple beneficial genes to rapidly improve rice blast resistance, yield, and quality using multiple breeding strategies.

Supplementary Information: The online version contains supplementary material available at 10.1007/s11032-021-01259-4.