Table 2.

Effects of 2,4-D on spike structure of selected double mutant lines (F₁₀) cultivated under field conditions

Mutant/hybrid	Treatment	n	Phenotypic group
			I	II	III	Others
Hv-tweaky spike 2 (Hv-tw2) (−)	0	282	0	17 ·7 ± 2 ·3	0	0
	2,4-D	288	0	0c	0	0
Hv-tw2 × Hv-Lh N1 (−)	0	420	13 ·3 ± 1 ·7	0 ·7 ± 0 ·4	0	0
	2,4-D	215	1 ·4 ± 0 ·8c	0	0 ·5 ± 0 ·5	0
Hv-tw2 × Hv-Lh N2 (+)	0	326	3 ·1 ± 1 ·0	2 ·8 ± 0 ·9	12 ·0 ± 1 ·8	1 ·5 ± 0 ·7
	2,4-D	322	0 ·6 ± 0 ·4a	1 ·6 ± 0 ·7	11 ·2 ± 1 ·8	1 ·2 ± 0 ·6
Hv-tw2 × Hv-Lh N11 (+)	0	262	20 ·2 ± 2 ·5	10 ·3 ± 1 ·9	15 ·3 ± 2 ·2	0
	2,4-D	210	16 ·7 ± 2 ·6	7 ·1 ± 1 ·8	5 ·2 ± 1 ·5c	0
Hv-tw2 × Hv-Lh N17 (+−)	0	324	9 ·3 ± 1 ·6	9 ·9 ± 1 ·7	18 ·5 ± 2 ·2	4 ·0 ± 1 ·1
	2,4-D	200	6 ·5 ± 1 ·7	15 ·5 ± 2 ·6	15 ·0 ± 2 ·5	9 ·0 ± 2 ·0a
Hv-tw2 × Hv-Lh N19 (+)	0	533	9 ·4 ± 1 ·3	12 ·4 ± 1 ·4	11 ·6 ± 1 ·4	0 ·4 ± 0 ·3
	2,4-D	435	3 ·4 ± 0 ·9c	17 ·2 ± 1 ·8a	2 ·5 ± 0 ·7c	0
Hv-tw2 × Hv-H N21 (+)	0	437	3 ·7 ± 0 ·9	14 ·9 ± 1 ·7	5 ·9 ± 1 ·1	0
	2,4-D	352	2 ·3 ± 0 ·8	2 ·0 ± 0 ·7c	9 ·7 ± 1 ·6	0
Hv-tw2 × Hv-H N6 (+)	0	147	3 ·4 ± 1 ·5	10 ·2 ± 2 ·5	2 ·7 ± 1 ·3	0 ·7 ± 0 ·7
	2,4-D	75	0a	2 ·7 ± 1 ·9a	1 ·3 ± 1 ·3	0

Phenotypic groups: I, with long naked gaps on rachis (Fig. 1A, F); II, with short gaps (Fig. 1G); III, leafy/shoot-like (Fig. 1H, I, K, L); for Hv-wt, Hv-Lh and Hv-H the above variations of spike structure are absent.

(+), (−) as in Table 1.

n, number of tested spikes; n for Hv-wt: 0–201; 2,4-D, 215; for Hv-Lemma hooded (Hv-Lh): 0–155; 2,4-D, 147; for Hv-Hooded (Hv-H): 0–193; 2,4-D, 173.

^a,b,cIn comparison with plants not treated with 2,4-D: ^aP < 0 ·05; ^bP < 0 ·01; ^cP < 0 ·001.