TABLE 2.

Effect of number of subpools per tail (S) under the FPD on characteristics Δ and SD of the confidence interval for QTL location, comparisonwise error rate (P-value), and statistical power, according to number of families (F), number of daughters per family (N), and standardized allele substitution effect at the QTL (d/σ), using simulated data

			Δ			SD			P-value			Power at P = 0.05
F	N	d/σ	S = 4	S = 6	S = 8	S = 4	S = 6	S = 8	S = 4	S = 6	S = 8	S = 4 (%)	S = 6 (%)	S = 8 (%)
1	1920	0.3	10.4	10.1	10.3	4.7	4.0	3.5	0.056	0.007	0.005	—	79	89
		0.2	14.1	14.0	13.7	14.6	12.0	10.7	0.083	0.043	0.028	—	32	56
		0.15	11.0	10.3	11.1	11.6	8.8	6.7	0.156	0.135	0.110	—	—	—
3	960	0.3	4.7	3.8	3.5	5.4	4.9	3.2	0.003	0.003	0.002	59	89	94
		0.2	10.3	12.1	12.0	11.4	7.1	6.9	0.030	0.021	0.023	30	52	52
		0.15	14.6	14.7	14.9	19.2	15.7	13.2	0.195	0.203	0.208	—	—	—
3	1920	0.3	2.9	3.1	3.2	1.9	1.5	1.2	0.001	0.001	0.001	94	99	99
		0.2	5.7	5.2	5.4	4.4	3.4	3.0	0.003	0.002	0.003	56	82	92
		0.15	10.7	10.1	10.1	6.9	5.6	5.1	0.028	0.024	0.011	46	72	76
5	960	0.3	2.7	2.9	2.9	2.6	1.8	1.6	0.001	0.001	0.001	87	99	99
		0.2	5.7	5.8	5.4	5.3	4.3	3.3	0.013	0.009	0.006	44	63	71
		0.15	14.3	15.1	14.9	12.0	9.6	8.4	0.081	0.070	0.067	—	—	—

P-values and power were calculated using the permutation test based on Σ(A_f)² (see text). Power was calculated for the threshold of the statistics corresponding to P-value = 0.05 (shown only for situations where the observed experimentwise P-value did not exceed 0.05). Characteristics Δ and SD of the confidence interval for QTL location were obtained from the jackknife iterations. Parameters of the simulations: chromosome length 120 cM. A single QTL was situated at position 40 cM. Number of markers M = 13. Proportion of population selected to each tail, 0.10. One subpool per tail was excluded in each jackknife. Values represent mean of 10 simulation data sets; for every data set 1000 permutations of subpools and 100 jackknife iterations were made to estimate P-value, power, Δ, and SD.