Table 3. Results of population- and individual-level hybridization detection analyses using HyDe (Blischak et al. 2018).

For each putative allotetraploid (Hybrid), Parent 1 and Parent2 are Crataegus subg. Sanguineae diploids^1,3 and C. subg. Americanae tetraploids², respectively (Table 1). Outgroups were the apple, C. monogyna (s21), C. germanica (s07), and C. brachyacantha (s10) accessions (Table 1). Results are shown for C. douglasii and C. rivularis at the population level, and then the individual level (Table 1), where $\hat{\mathrm{\gamma }}$ is the admixture statistic, tested for H₀: γ = 0 versus H₁: γ > 0.

Parent1	Hybrid	Parent2	Z-score	P-value	$\hat{\gamma }$
SANG1	C. douglasii	AMER2	7.287	1.594 × 10-13	0.67244
SANG1	s03dou	AMER2	7.815	2.776×10-15	0.60647
SANG1	s16dou	AMER2	6.017	8.938 ×10-10	0.75688
SANG1	s19dou	AMER2	7.676	8.216 ×10-15	0.64428
SANG3	C. rivularis	AMER2	10.001	0.0	0.73466
SANG3	s20riv	AMER2	10.011	0.0	0.69301
SANG3	s04riv	AMER2	9.751	0.0	0.77420
SANG3	s12riv	AMER2	10.178	0.0	0.72819

Notes.

¹C. suksdorfii s15, s24.

²C. chrysocarpa s06, s17, C. macracantha s11, s18.

³C. saligna s13, s14.