Effects of variety degeneration on yield formation, quality traits and 2-acetyl-1-pyrroline biosynthesis in high-quality Japonica rice

The main purpose of the present study was to study the degeneration of the high-quality japonica rice varieties during long-term cultivation, with a focus on changes in yield, rice quality and indices related to 2-acetyl-1-pyrroline (2-AP) biosynthesis, to provide a scientific basis for the comprehensive purification and improvement of high-quality rice varieties. By selecting the lines from the populations of Nanjing 9108 and Nanjing 46 at Liyang, it was found that the mutant lines showed significant differences in the yield and yield components, processing and appearance quality, cooking and flavor quality, rapid viscosity analyser profile characteristics and 2-AP content. Molecular marker detection can be used as a primary method for seed purity identification. The results revealed that the 2-AP content was positively correlated with proline activity, ProDH activity and δ-OAT activity but negatively correlated with BADH2 activity. Through stepwise discriminant analysis, it was determined that 1000-grain weight and trough viscosity could be used as core indicators for discriminating line variations.