. 2018 Aug 24;13(8):e0203080. doi: 10.1371/journal.pone.0203080

Table 2. Effects of seed water content (SWC) and cryopreservation (LN) on normal seed germination in Populus davidiana and P. koreana.

Seed water content (SWC, %)	Normal germination (%)
	P. davidiana		P. koreana
	-LN	+LN	-LN	+LN
After seed cleaning	97 ± 3.3		87 ± 9.7
3	96 ± 3.3^{ns z}	84 ± 7.3^c	28 ± 5.7^c	27 ± 7.6^c
6	95 ± 5.0	100 ± 0.0^a	63 ± 6.8^a	67 ± 9.2^a
9	100 ± 0.0	95 ± 3.8^ab	75 ± 10.5^a	78 ± 12.4^a
12	98 ± 2.3	98 ± 2.3^ab	76 ± 7.3^a	72 ± 6.5^a
18	97 ± 3.8	93 ± 6.8^ab	43 ± 10.1^b	43 ± 11.0^b
21	96 ± 0.0	90 ± 5.2^bc	36 ± 5.7^bc	38 ± 2.3^bc
24	96 ± 4.6	90 ± 5.2^bc	38 ± 12.0^bc	38 ± 5.2^bc
Significance
SWC	^***		^***
LN	^**		ns
SWC × LN	^*		ns

Values are means of four replicates ± SD (n = 4). Different letters indicate statistically significant differences among seed water content within non-treated (-LN) or cryopreserved (+LN) seeds at p<0.05, according to Duncan’s multiple range test in each species. ^zNo significant different between non-treated (-LN) and cryopreserved (+LN) seeds in both species.

*, **, and *** indicate significant difference at p<0.05, p<0.01, and p<0.001, respectively, and ns indicates non-significance.