Efficient Production of Doubled Haploids as Isogenic Line Founders via Double Heat Shock Treatment in Willow Gudgeon (Gnathopogon caerulescens)

Table 4

Comparison of the proportion of doubled haploids in hatched larvae and the successfully induced doubled haploid and yield in each experimental group activated gynogenetically in experiments I and II.

Exp		Experimental group	Timing of HST		N	Hatching stage
			1st	2nd		Rate of induced DHs (%)^†	Yield of DHs (%)^‡
I		GC	—	—	6	0 ± 0^c	0 ± 0^c
	Single HST	F23	23	—	3	0 ± 0^c	0 ± 0^c
		F25	25	—	6	0 ± 0^c	0 ± 0^c
		F26	26	—	3	0.9 ± 1.6^c	0.9 ± 1.6^c
		F27	27	—	6	0 ± 0^c	0 ± 0^c
		F28	28	—	3	0 ± 0^c	0 ± 0^c
		F29	29	—	6	0 ± 0^c	0 ± 0^c
		F31	31	—	3	0.3 ± 0.5^c	0.3 ± 0.5^c
	Double HST	F23S39	23	39	3	9.3 ± 7.2^a	7.5 ± 5.7^a
		F25S41	25	41	6	6.3 ± 4.7^ab	4.7 ± 5.0^ab
		F26S42	26	42	3	1.2 ± 0.5^c	0.6 ± 0.5^c
		F27S43	27	43	6	3.1 ± 3.8^bc	2.8 ± 4.0^bc
		F28S44	28	44	2	1.3^❡	1.3^❡
		F29S45	29	45	6	1.8 ± 2.6^c	1.6 ± 2.2^bc
		F31S47	31	47	3	3.8 ± 5.4^bc	3.2 ± 4.2^bc
II		GC	—	—	3	0 ± 0^b	0 ± 0^b
	Single HST	F26	26	—	3	0 ± 0^b	0 ± 0^b
	Double HST	F26S37	26	37	3	4.1 ± 4.6^a	3.1 ± 2.8^a
		F26S39.5	26	39.5	2	1.8^❡	0.7^❡
		F26S42	26	42	2	1.1^❡	0.3^❡
		F26S44.5	26	44.5	1	2.1^❡	0.7^❡
		F26S47	26	47	1	0^❡	0^❡
		F26S49.5	26	49.5	3	0 ± 0^b	0 ± 0^b
		F26S52	26	52	3	0.2 ± 0.3^b	0.2 ± 0.3^b

, min after fertilisation. N, number of replicates of the attempts. GC, gynogenetic control, which was activated with UV-sperm, but not treated with heat shock. ^†, rate of induced DHs (%), rates of induced doubled haploids in hatched larvae: x × h × z × 100. ^‡, yield of DHs (%), yields of normally doubled haploid hatched larvae: x × y × h × z × 100. “x,” the hatching rate; “y,” the rate of morphologically normal larvae; “h,” the rate of homozygotes among diploids judged by the analysis of microsatellite genotype; “z,” the rate of diploidy determined by analysis of ploidy. The values of the rate of induced DHs and yield of DHs are corrected in consideration of the results of the Gras-Di analysis (×0.739). This means within each column that are not sharing a common superscript are significantly different (). ^❡, the variability was not calculated because the sample size was not sufficient. These experimental data were excluded from the comparison of mean values.