Table 4.

Additive x additive (A1 x A2) epistatic interactions detected by QTLNetwork for spike shattering scores (1–9 scale), interacting QTL intervals (QTL1 and QTL2), and levels of significance (P value) for QTL identified in the Carberry/Thatcher and Carberry/AC Cadillac doubled haploid populations evaluated near Swift Current, Canada in different years

	QTL1	Interval 1	Position, cM	QTL2	Interval 2	Position, cM	A1 x A2 effect	P Value
Carberry/Thatcher
Centre Farm 2016	4B	BS00081631_51-Tdurum_Contig55414_154	96.16–120.58	5A	Wsnp_Ex_C1880_3545329 - Wsnp_Ex_C18107_26909127	187.62–189.67	0.25	< 0.001
Centre Farm 2018	4B	IACX557-Tdurum_Contig64772_417	109.91–121.5	5A	Wsnp_Ex_C18107_26909127 - Wsnp_Ex_C1481_2831499	189.67–198.41	0.39	< 0.001
Field 17 2018	4B	IACX557-Tdurum_Contig64772_417	109.91–116.24	5A	Wsnp_Ex_C16715_25264080 - Wsnp_Ex_C1880_3545329	186.59–187.62	0.25	< 0.001
South Farm 2019	4B	IACX557-Tdurum_Contig64772_417	109.91–116.24	5A	Wsnp_Ex_C18107_26909127 - Wsnp_Ex_C1481_2831499	189.67–198.41	0.33	< 0.001
Location-year mean	4B	IACX557-Tdurum_Contig64772_417	109.91–116.24	5A	Wsnp_Ex_C16715_25264080 - Wsnp_Ex_C1880_3545329	186.59– 187.62	0.28	< 0.001

Carberry/AC Cadillac
Centre Farm 2012	3A	Wsnp_Ku_C44716_51926415-Wsnp_Rfl_Contig2699_2402527	101.45–104.65	4B	Bs00021984_51-Wsnp_Bf482960b_Ta_1_4	107.87–111.2	− 0.16	< 0.001
South Farm 2012	4B	Ex_C101685_705 - Tdurum_Contig41902_1524	111.33–121.56	5A	Wsnp_Ex_C3772_6866645 - Wsnp_Ex_C31672_40435001	180.73–190.13	0.13	< 0.005
	5A	Wsnp_Ex_C3772_6866645 - Wsnp_Ex_C31672_40435001	180.73–190.13	7D	Rac875_C10636_525 - Ku_C17958_576	12–23.78	− 0.18	< 0.001
	7A.2	Bs00071425_51 - Bs00063458_51	152.99–156.82	7D	Rac875_C10636_525 - Ku_C17958_576	12–23.78	− 0.12	0.006
Centre Farm 2013	1A	Rac875_C60514_90-Bobwhite_C7337_717	119.46–120.12	4B	Ex_C101685_705–Tdurum_Contig41902_1524	111.33–121.56	− 0.07	0.013
	4B	Excalibur_C29141_864 - Excalibur_C17607_542	98–104.81	5A	Wsnp_Ex_C18107_26909127 - Wsnp_Ex_C1481_2831499	198.63–205.24	0.17	< 0.001
	5A	Wsnp_Ex_C18107_26909127 - Wsnp_Ex_C1481_2831499	198.63–205.24	7D	Ku_C17958_576 - Excalibur_C13094_523	23.78–30.35	− 0.07	0.015
South Farm 2013	2D	Rac875_C10626_2089 - Bs00022941_51	22.39–23.07	5A	Wsnp_Jd_C43389_30288993 - Cap8_Rep_C4852_130	206–206.16	− 0.08	0.028
	3A	Excalibur_C63733_173 - Wsnp_Ku_C44716_51926415	99.2–101.45	4B	Bs00021984_51 - Wsnp_Bf482960b_Ta_1_4	107.87–111.2	− 0.09	0.017
	3A	Excalibur_C63733_173 - Wsnp_Ku_C44716_51926415	99.2–101.45	5A	Wsnp_Ex_C3772_6866645 - Wsnp_Ex_C31672_40435001	180.73–190.13	− 0.1	0.007
	4B	Bs00021984_51 - Wsnp_Bf482960b_Ta_1_4	107.87–111.2	7D	Ku_C17958_576 - Excalibur_C13094_523	23.78–30.35	− 0.1	0.006
	4B	Bs00021984_51 - Wsnp_Bf482960b_Ta_1_4	107.87–111.2	5A	Wsnp_Ex_C3772_6866645 - Wsnp_Ex_C31672_40435001	180.73–190.13	0.2	< 0.001
	5A	Wsnp_Ex_C3772_6866645 - Wsnp_Ex_C31672_40435001	180.73–190.13	7D	Ku_C17958_576 - Excalibur_C13094_523	23.78–30.35	− 0.16	< 0.001
Field 16 2014	4B	Excalibur_C29141_864 - Excalibur_C17607_542	98–104.81	5A	Wsnp_Ex_C18107_26909127 - Wsnp_Ex_C1481_2831499	198.63–205.24	0.09	< 0.001
	5A	Wsnp_Ex_C18107_26909127 - Wsnp_Ex_C1481_2831499	198.63–205.24	7A.2	Kukri_C33036_348 - Rac875_C17000_731	139.97–142.61	0.08	< 0.001
Location-year mean	4B	Excalibur_C29141_864 - Excalibur_C17607_542	98–104.81	5A	Wsnp_Ex_C18107_26909127 - Wsnp_Ex_C1481_2831499	198.63–205.24	0.11	< 0.001
	5A	Wsnp_Ex_C3772_6866645 - Wsnp_Ex_C31672_40435001	180.73–190.13	7D	Ku_C17958_576 - Excalibur_C13094_523	23.78–30.35	− 0.09	< 0.001
	7A.2	Bs00063458_51 - Tplb0036a12_207	156.82–157.34	7D	Ku_C17958_576 - Excalibur_C13094_523	23.78–30.35	− 0.06	0.015