Fig. 3

Dual functions of S1TPR in S1 HS. a F₁ hybrids from crossing RP-s with NIL-g exhibited typical semi-sterile pollen and spikelets. b The pollen and spikelets of the mutant F₁ (mF₁) plants from crosses between RP-s and the CRISPR-knockout mutant s1tpr (tpr) in NIL-g (g^mg^m) were fully fertile. c The F₁ plants from a cross between the S1TPR^t (TPR^t, ss/TT) and tpr (g^mg^m) lines exhibited semi-sterile pollen and spikelets. Bars in (a–c) represent 50 μm for pollen and 5 cm for panicles. d A proposed model for the segregation of the S1 alleles and transgenes in the F₂ progeny of the TPR^t × tpr cross. The F₁ male and female gametes containing the T allele (gray background) are fertile, and those without T (white background) generally abort. The color codes are consistent with the genotype of the individuals in the F₂ population. Black represents homozygous TPR^t; green represents homozygous S1-s; pink represents heterozygous mutated S1; light blue represents homozygous mutated S1-g^m. e Segregation rates of the S1 alleles and transgenes (T) in the F₂ plants shown in (a–c). ***P < 0.001 in the Χ² test. Source data of (e) are provided as a Source Data file