Marker-assisted selection strategy to pyramid two or more QTLs for quantitative trait-grain yield under drought

Rice

Table 5 Mean comparison of QTL classes of grain yield (kg ha⁻¹) across BC₁F₃ to BC₁F₇ generations under reproductive-stage drought stress and irrigated non-stress control conditions in MR219 background at IRRI, Philippines

QTL class	QTL	2013DS		2014DS		2015DS
		NS	RS	NS	RS	NS	RS
		BC₁F₃	BC₁F₃	BC₁F₅		BC₁F₇	BC₁F₇
Population size
		214	214	620	620	70	70
A	qDTY _12.1	6229 a	654 b	6967 b	301 a	–	–
B	qDTY_12.1 + qDTY_2.2	6633 b	761 bc	7364 ac	598 b	5986 a	540 c
C	qDTY_12.1 + qDTY_3.1	6652 ac	1072 d	7532 cd	794 e	7111 c	672 d
D	qDTY _2.2	6760 ab	904 cd	7079 ba	669 bc	6957 c	393 b
E	qDTY_2.2 + qDTY_3.1	7158 bc	1112 d	7243 cd	663 c	6843 bc	679 d
F	qDTY_2.2 + qDTY_3.1 + qDTY_12.1	6799 ab	642 b	7106 ad	442 b	6674 bc	578 cd
G	qDTY _3.1	6488 a	890 c	7374 ac	568 c	6923 bc	537 bcd
X	Parent	5917 ab	13 a	6519 b	0 ab	6148 ab	0 a
Trial mean		6705	781	7173	505	6663	486
F- value		2.0	11.76	9.45	19.39	7.76	6.18
p-value		0.05	< 0.0001	< 0.0001	< 0.0001	0.0004	<.0001

The letter display are QTL class labels ordered by mean grain yield of QTL class. Means followed by the same letter (within a column) are not significantly different, DS dry season, WS wet season, NS non-stress, RS reproductive-stage drought stress, X recipient parent (no QTL)