Fig. 1. In vivo maternal haploid induction in rice through parthenogenesis gene ToPAR. A, Schematic representation of vector constructed for the ectopic expression of ToPAR in egg cells. GFP, Green fluorescent protein; T, Terminator. B, Genotyping analysis of eeTP (ectopic expression of ToPAR) plants. eeTP-1 to -30 represent eeTP lines; CY84, Chunyou 84, wild type; M, Marker. C, Plant and panicle morphology of CY84 and eeTP-8. Scale bars are 20 cm for plant and 5 cm for panicle. D, Seed-setting rates of CY84 and eeTP lines. E, Identification of haploids using 12 InDel (insention/deletion) markers. 16A and C84 are two parental materials; 1 and 2 represent two haploid plants. F, Haploid induction rates (HIRs) and seed-setting rates of eeTP-8 and eeTP-14. G, Flow cytometric analysis of ploidy levels in CY84 and progeny of eeTP. PI, Propidium iodide. H, Comprehensive whole-genome sequencing of 16A, C84, CY84, and its haploids (-1 and -2). The single nucleotide polymorphisms of 16A, C84, and CY84 are highlighted in red, blue, and yellow, respectively, across the 12 chromosomal blocks. 16A and C84 were served as the reference controls. Chr, Chromosome. I, Morphological comparison of diploid and haploid offspring, including plant and panicle morphology. Scale bars are 20 cm for plant and 5 cm for panicle. In D and F, data are Mean ± SD (n ≥ 3). ns, No significance; *, P < 0.05; **, P < 0.01; ***, P < 0.001 determinded by the Student’s t-test.