Table 1.

Gene density, No. of PGRS, ω ratios range, mean ω ratio, and median ω ratio in poplar and willow genome

Chromosome	P. trichocarpa						S. suchowensis
	Genes/Mb	No. of PGRS	PGRS/Mb	ω ratios range	Mean ω ratio	Median ω ratio	Genes/Mb	No. of PGRS	PGRS/Mb	ω ratios range	Mean ω ratio	Median ω ratio
I	93.7	2066	40.9	0.000–2.493	0.312	0.278	100.4	1000	38.0	0.000–0.904	0.273	0.253
II	104.5	1382	54.7	0.000–2.020	0.312	0.282	113.5	822	50.6	0.000–1.398	0.275	0.250
III	102.7	1122	51.4	0.000–2.493	0.311	0.273	114.2	710	58.0	0.000–1.177	0.281	0.255
IV	97.7	1020	42.0	0.000–2.114	0.303	0.275	106.0	605	45.1	0.009–0.943	0.261	0.249
V	100.6	1302	50.3	0.000–1.705	0.305	0.276	113.6	768	55.2	0.000–1.123	0.282	0.254
VI	100.8	1305	46.8	0.000–1.228	0.305	0.276	114.0	741	44.9	0.000–0.863	0.270	0.253
VII	94.4	635	40.7	0.000–1.282	0.304	0.272	103.8	314	38.1	0.000–0.859	0.279	0.252
VIII	116.4	1289	66.2	0.000–1.702	0.311	0.277	119.9	775	64.4	0.000–0.953	0.276	0.253
IX	131.8	892	68.9	0.000–2.114	0.304	0.274	122.4	518	54.0	0.000–0.943	0.263	0.251
X	113.2	1289	57.1	0.000–1.702	0.311	0.277	121.7	775	54.7	0.000–0.953	0.276	0.253
XI	91.9	700	37.8	0.008–1.779	0.315	0.279	91.2	357	32.2	0.008–0.904	0.276	0.248
XII	92.5	669	42.4	0.000–1.054	0.304	0.276	94.0	279	38.3	0.000–0.733	0.272	0.247
XIII	99.1	614	37.6	0.000–1.569	0.313	0.281	98.7	338	31.4	0.022–0.798	0.277	0.248
XIV	104.9	774	40.9	0.000–2.020	0.312	0.281	119.4	419	39.7	0.000–1.398	0.267	0.248
XV	97.2	656	42.9	0.000–1.054	0.301	0.274	110.8	386	44.4	0.000–0.763	0.267	0.239
XVI	99.5	677	46.7	0.000–1.228	0.304	0.277	121.4	710	53.7	0.000–1.177	0.281	0.255
XVII	96.6	530	33.0	0.013–1.353	0.318	0.292	98.5	270	31.6	0.009–0.749	0.268	0.249
XVIII	90.0	641	37.8	0.000–1.216	0.308	0.276	97.7	312	38.2	0.013–0.734	0.278	0.252
XIX	84.1	395	24.8	0.010–1.271	0.318	0.288	89.4	223	27.1	0.022–0.798	0.265	0.242
SDR	85.3	26	11.9	0.010–1.271	0.317	0.233	79.7	11	14.9	0.092–0.396	0.237	0.223
Genome wide	100.2	8991	22.8	0.000–2.493	0.309	0.277	108.8	5161	22.5	0.000–1.398	0.274	0.252