四倍体水稻HD659的选育及其遗传稳定性分析OA

[Objective]This study aims to develop superior polyploid rice germplasms using meiotically stable materials and systematically ana-lyze their genetic stability,thereby providing both material foundation and theoretical basis for overcoming the breeding bottleneck of polyploid rice.[Method]The pedigree selection method was employed to screen elite individual plants from the tetraploid rice HN16CX160-4x popula-tion.After continuous strict self-pollination and purification over multi-generation,the target material HD659-4x was obtained.Ploidy identifica-tion was conducted through root tip chromosome counting and flow cytometry.Major agronomic traits were investigated and statistically analyzed for three consecutive years(2018-2020)in Wuhan.Genetic stability was assessed using SSR molecular markers,and grain quality analysis was performed on sister lines.[Result]A new tetraploid rice line HD659-4x(2n=4x=48)was successfully bred.This line belongs to an indi-ca-japonica intermediate conventional rice type,featuring a moderately loose plant architecture with flag leaf angles ranging from 35° to 45°.It exhibits strong tillering ability,1 000-grain weight of approximately 38 g,seed setting rate of about 79.53%,average tiller number of 10.4,and a plot yield equivalent to 9 548.9 kg/hm2,demonstrating stable high-yield potential.SSR marker analysis revealed high genetic consistency and excellent stability across materials from three consecutive generations(2018-2020).Grain quality analysis indicated that the four sister lines generally exhibited ordinary rice quality,but contained superior variations in quality traits that could serve as foundational materials for quality improvement.[Conclusion]HD659-4x is a genetically stable tetraploid rice line with superior agronomic traits,serving as an excellent chassis material for polyploid rice breeding.It holds significant breeding application value and is expected to accelerate the development of tetraploid rice cultivars.