Improvement in the quality of the water-saving and drought-resistant rice ‘Huhan 1516’ via molecular markers

To improve the rice quality of the water-saving and drought-resistant rice variety 'Huhan 1516' and cultivate high-yield, high-quality new lines of water-saving and drought-resistant rice. In this study, we used 'Meixiangzhan 2', which carries the flavour gene <i>Badh2</i>, as the donor parent and 'Huhan 1516', which contains the rice blast resistance gene <i>Pi2</i>, as the recipient parent and comprehensively utilized molecular marker-assisted selection (MAS) and the WDR 6K microarray detection system for selection. In addition, resistance identification and rice quality testing were conducted. A total of four improved lines of 'Huhan 1516' (YN13, YN14, YN15, and YN16) were ultimately selected. The results show that the resistance to bacterial blight in the improved strain significantly increased, while the resistance to rice blast and agronomic traits were comparable to those of 'Huhan 1516', with a background recovery rate of 92.6%-95.4%. Compared with that of 'Huhan 1516', the content of amylose decreased from 17.8% to 15.4%-16.5%, and the differences in gel consistency and alkali spreading value were not significant. There was a reduction in chalkiness and the chalky grain percentage, with transparency changing from level 2 to level 1. Additionally, the content of the aromatic compound 2AP significantly increased to 0.44-0.71 mg/kg, leading to a marked improvement in eating quality. The successful development of the improved line not only meets the market demands for high-yield, high-quality, water-saving, and drought-resistant rice varieties but also expands the application potential of 'Huhan 1516'. Furthermore, this study provides theoretical support and material resources for the breeding of high-quality, water-efficient, and drought-tolerant rice.