Table 2.
Flow cytometry seed analyses of functional pathways for seed formation in different Ranunculus hybrid types
| Hybrid type | No. of individuals | No. of seeds | Seed class | Peak index Mean ± SD | Range of peak indexes | Maternal : paternal genomes in the endosperm1 | Functional paths (%) ± SD |
|---|---|---|---|---|---|---|---|
| 2x syn | 15 | 501 | Sex | 1.55 ± 0.08 | 1.38–1.79 | 2m : 1p | 100.0 ± 0.0 |
| – | Apo | – | – | –2 | 0.0 ± – | ||
| 3x syn | 10 | 58 | Sex | 1.64 ± 0.14 | 1.30–1.88 | c. 2m : 1p | 95.1 ± 7.6 |
| 2 | Apo | 2.45 ± 0.05 | 2.42–2.49 | c. 4m : 1p3 | 3.3 ± 5.6 | ||
| 1 | BIII | 1.69 ± – | – | c. 4m : 1p3 | 1.6 ± 0.0 | ||
| 6x nat | 10 | 214 | Sex | 1.65 ± 0.13 | 1.48–1.99 | 2m : 1p | 29.1 ± 12.4 |
| 520 | Apo | 2.62 ± 0.21 | 2.33–3.07 | 2m : 1p or 4m : 1p | 70.9 ± 12.4 |
syn, synthetic; nat, natural; Functional paths, effective reproductive pathways within each analysed hybrid type; SD, standard deviation of the sample or among genotypes; sex, sexual derived seeds; apo, asexual derived seeds; BIII, seed derived from fertilisation of an unreduced embryo sac.
Genome contributions inferred from embryo sac structure, ploidies of embryo and endosperm tissues (Fig. 3; Table 3), expected gamete ploidies and observed chromosome numbers of F2 individuals (Supporting Information Table S6). Due to aneuploid gametes, only approximate genomic contributions are inferred for triploid individuals.
The expected ratio derived from an unreduced embryo sac would be 4m : 1p.
According to embryo ploidy and peak index, a near 1.5x male gamete has fertilised the polar nuclei.