Rj. Summerfield et al., Characterization of the photoperiodic response of post-flowering development in maturity isolines of soyabean [Glycine max (L.) Merrill] 'Clark', ANN BOTANY, 82(6), 1998, pp. 765-771
Plants of all eight isolines of three maturity genes tall combinations of t
wo alleles at the three loci E-1/e(1), E-2/e(2), E-3/e(3)) of soyabean [Gly
cine max (L.) Merrill] were grown in four different photoperiods (12, 13, 1
4 or 15 h d(-1)) at 30/24 degrees C from first flower opening to harvest ma
turity. Photoperiod, isoline, and their interaction, affected significantly
(P < 0.01) the duration between first and last flowering, and reproductive
duration. The interactions between genotype and photoperiod were sufficien
tly strong that considerable differences in these durations were detected a
mong isolines in the least-inductive environment(l5 h d(-1)) whereas differ
ences were negligible in the most-inductive regime (12 h d(-1)). There was
a negative linear relation between photoperiod and both rate of progress fr
om the appearance of the first to the last flower, and rate of progress fro
m first flowering to harvest maturity; sensitivity to photoperiod varied (P
< 0.05) six- and live-fold, respectively, among the extreme isolines (e(1)
e(2)e(3) and E1E2E3). The three dominant alleles E-1, E-2 and E-3, singly,
had comparatively little effect on post-flowering traits, but considerable
epistasis (particularly between E-1 and E-2) was detected for sensitivity t
o photoperiod in respect of rates of progress from the appearance of the fi
rst to the last flower, and from first flower to harvest maturity. Thus the
large variations detected for these traits are the consequence of gene x g
ene (x gene) x environment interactions. (C) 1998 Annals of Botany Company.