DMS-TD: A powerful genetic tool for outcross breeding in rice

This is the authors' abstract. We don't add key points for this paper.

Rice hybrid breeding relies heavily on manual emasculation, a labor-intensive process characterized by high rates of false hybrids and low operational efficiency, limiting its applicability for intelligent design breeding. To address these constraints, we engineered a dominant male sterility system based on TDR , designated DMS-TD, through ectopic co-expression of rice tapetum degeneration regulatory gene TDR and a red fluorescent protein gene DsRed2 . DMS-TD plants exhibited complete and stable male sterility across diverse genetic backgrounds and environments. Furthermore, the sterility trait was stably inherited by the progeny. Fluorescent marker–assisted seed sorting facilitated the segregation of DMS-TD seeds and fertile seeds before sowing. In field trials, DMS-TD plants achieved natural outcrossing rates of 32.63 ± 7.51%, producing hybrid seeds with intact hull structures, enhanced mildew resistance, and increased seed viability. Importantly, DMS-TD significantly enhanced hybridization efficiency by eliminating the need for manual emasculation. Based on this system, we generated both low-cadmium, multi-resistant germplasm resources via multigene stacking and indica – japonica hybrid intermediates through recurrent selection cycles. This genetic tool overcomes the limitations of existing dominant male-sterile materials and provides an automation-compatible pollination receptor for hybrid rice breeding, which could accelerate the transition toward automation and intelligent design breeding.