Table 4. QTLs detected in the Grand Rapids × Iceberg population by mixed-model based composite interval mapping performed on final ratings of the seven experiments.

QTL	LG	Position in cM	Range in cMa	ab ± S.E.	Significancec
qDM2.1	2	63.6	62.6 – 63.7	0.117 ± 0.022	> 6.0
qDM5.1	5	29.6	28.6 – 29.8	0.147 ± 0.022	> 6.0
qDM9.1	9	30.1	29.1 – 31.1	−0.088 ± 0.024	3.5

^aRange of the QTL support interval calculated by QTLNetwork software.

^bAdditive main effect (± standard error) of the QTL. Positive values indicate that alleles for elevated resistance originate from cv. Iceberg, while negative values indicate that alleles for elevated resistance originate from cv. Grand Rapids.

^cSignificance of the QTL expressed as negative common logarithm of P value.