Example of Commercial Hybrid Maize Program

1
Example of Commercial Hybrid Maize Program Su.
1 Grow 45 F2 or BC1 populations (S0 generation)
that have been formed in previous years Select
S0 plants in each population based on plant type
and disease and insect resistance Self and
testcross 50 selected S0 plants (essentially
random since before pollination/maturitycws) in
each population to an inbred or sc tester Thus
you initiate 2250 inbred lines and produce 2250
test cross hybrids
2
Example of Commercial Hybrid Maize Program Su.
2 Discard not more than 5 F2 or BC1 populations
based on performance data of the parents during
Su. 1. (i.e., 45 5 40 parents remaining or
2000 potential inbred lines) Grow 2000 S0
testcrosses in unreplicated trials at 3
locations. (How many seed do you need?) In each
S1 family (or line should be 2000) self 3 plants
to produce S2 subfamilies. DISCARD S1 families
that appear inferior. Select the best 200 S2
families, or lines, based on their S0 test cross
hybrid performance
3
Example of Commercial Hybrid Maize
Program Wi Cross 600 selected S2 families, or
lines, to each of 2 inbred testers Self these
600 S2 families to produce S3 families Su
3 Evaluate 1200 S2 testcross hybrids in
unreplicated trials at 6 to 10 locations Select
5 to 10 S3 families based on their S2 testcross
performance Wi Self the selected S3 families to
obtain S4 seeds NOTE, families are now referred
to as inbred lines
4
Example of Commercial Hybrid Maize Program Su
4 Cross each new inbred with 5 to 10 elite
inbred lines Self the S4 to produce the S5 seed
of new inbreds Su 5 Yield trials of experimental
hybrids at 15 to 50 locations (How many seeds do
you need?) Self the S5 to produce the S6 Su
6 Yield trials of advanced hybrids at 20 to 50
locations (advanced hybrids are those created by
crossing the new inbreds with 5 to 10 elite
inbreds in Su 4 that preformed well in Su. 5)
(How many seeds do you need?) On-farm strip
tests (12 rows x 1000 feet long) at 30 to 50
locations (How many seeds do you need?)
5
Example of Commercial Hybrid Maize Program Su
7 On-farm strip tests of precommercial hybrids
at 50 to 1500 locations (How many seed do you
need?) Fall Release 0 to 2 new hybrids for
commercial production
6
Wisconsin Quality Synthetic A synthetic corn
population, referred to as the Wisconsin Quality
Synthetic (WQS), has been developed by the UW
corn breeding program over the past fifteen years
to have high-quality stover and high forage
yield. Briefly, WQS is a broad-based synthetic
with a maturity of approximately 100 to 110RM. As
a silage, WQS was selected to have low neutral
detergent fiber (NDF), high in vitro true
digestibility (IVTD), and high in vitro NDF
digestibility (IVNDFD). It is approximately 50
Lancaster background (H99 and Mo17) and 50
broad-based high-quality germplasm from northern
temperate regions. Inbreds derived from WQS
combine well with inbreds derived from the Stiff
Stalk Synthetic.