Use of appropriate nursery environments will maximize gain from select
ion for yield of wheat (Triticum aestivum L.) in the target population
of environments of a breeding program. The objective of this study wa
s to investigate how well-irrigated (low-stress) nursery environments
predict yield of lines in target environments that varied in degree of
water limitation, Fifteen lines were sampled from the preliminary yie
ld evaluation stage of the Queensland wheat breeding program and teste
d in 26 trials under on-farm conditions (Target Environments) across n
ine years (1985 to 1993) and also in 27 trials conducted at three rese
arch stations (Nursery Environments) in three years (1987 to 1989). Th
e nursery environments were structured to impose different levels of w
ater and nitrogen (N) limitation, whereas the target environments repr
esented a random sample of on-farm conditions from the target populati
on of environments, Indirect selection and pattern analysis methods we
re used to investigate selection for yield in the nursery environments
and gain from selection in the target environments, Yield under low-s
tress nursery conditions was an effective predictor of yield under sim
ilar low-stress target environments (r = 0.89, P < 0.01). However, the
value of the low-stress nursery as a predictor of yield in the water-
limited target environments decreased with increasing water stress (mo
derate stress r = 0.53, P < 0.05, to r = 0.38, P > 0.05; severe stress
r = -0.08, P > 0.05), Yield in the stress nurseries was a poor predic
tor of yield in the target environments, Until there is a clear unders
tanding of the physiological-genetic basis of variation for adaptation
of wheat to the water-limited environments in Queensland, yield impro
vement can best be achieved by selection for a combination of yield po
tential in an irrigated low-stress nursery and yield in on-farm trials
that sample the range of water-limited environments of the target pop
ulation of environments.