Evaluation of Advanced GEM Lines
for Multiple Insect Resistance and
Fumonisin Concentration
Martin Bohn
Crop Sciences
University of Illinois
Objectives
Evaluate GEM lines for their
resistance against WCR as well as
first and second generation ECB.
Evaluate GEM lines for their
resistance against Fusarium species.
Determine the association between
insect resistance and fumonisin
concentration in GEM germplasm.
Objectives
Study the genetic basis of insect
resistance in maize against both
insect species by diallel crosses and
testcrosses, and
Initiate a recurrent selection program
aimed to develop new maize lines with
improved multiple insect resistant
(MIR).
Approach
Maize
WCR
ECB
GEM-Pop. (25%)
GEM-Pop. (100%)
Materials and Methods
“Population”
“Inbred”
15 Entries
20 Entries
Location:
Urbana
Design:
α – lattice, 4 replications
Plot size:
Population – 4 row plots
Inbreds
- 2 row plots
Row size:
1.50m × 0.75m
10-12 plants hand planted
WCR eval.:
Trap crop
ECB eval.:
1ECB – 180 eggs / plant
2ECB – 180 eggs / plant
Materials and Methods: WCR
Node-Injury Scale (0.00 – 3.00)
(Oleson and Tollefson, Iowa State Uni.)
1.50
No. of full
nodes eaten
% of a node
eaten
0.00
3.00
Materials and Methods: ECB
Leaf Damage Rating
1 = no visible leaf feeding
9 = long lesions on most
leaves
Source: D. Barry
Stalk Damage Ratings
1 = no stalk breakage
9 = stalk breakage beneath
the ear
Number of Larvae
Source: T. Magg
Results: Populations
Root Damage Ratings (0.00 – 3.00)
0.60
MIN
0.88
1.00
MEAN 1.40
MAX
1.74
1.80
DKXL212:N11a01
UR10001:N1708b
UR10001:N1702
CH05015:N1204
DKB844:S1612
NGSDCRW1(S2)C4-15-2S2(S1)
FS8A(T):N1804
FS8A(S):S0907
CASH:N1410
AR17056:N2025
AR16026:S1719
AR13035:S11b04
AR17056:S1216
UR13085:N0204
AR16026:N1210
LSD(5%) = 0.99
http://www.ent.iastate.edu/pest/rootworm/nodeinjury/nodeinjury.html
Results: Inbreds
Root Damage Ratings
(0.00 – 3.00)
MIN
0.50
0.56
MEAN
1.08
1.50
MAX
1.73
2.00
LSD(5%) = 0.74
CUBA117:S1520-153
AR17056:N2025-728
B64
CUBA117:S1520-182
AR17056:N2025-#5
AR17056:N2025-522
CUBA117:S1520-52
CUBA117:S1520-41
CUBA117:S1520-156
AR17056:N2025-546
AR17056:N2025-508
AR17056:N2025-#2
AR17056:N2025-532
B37
Mo17
AR17056:N2025-#4
NGSDCRW1(S2)C4-15
AR17056:N2025-#1
AR17056:N2025-#3
B73
http://www.ent.iastate.edu/pest/rootworm/nodeinjury/nodeinjury.html
Results: ECB
Evaluation of inbreds derived from
GEM populations (25% exotic) for
various ECB resistance traits.
LDR
SDR1
SDR2
1ECB
2ECB
Mean
SE
Min
Max
3.97
2.34
3.96
2.51
3.46
0.68
0.82
0.64
0.84
0.78
3.18
1.82
3.04
1.85
2.45
5.25
2.96
5.44
3.52
4.54
SE = Standard error
Results: ECB
Evaluation of GEM populations (25%
exotic) for various ECB
resistance traits.
LDR
SDR1
SDR2
1ECB
2ECB
Mean
SE
Min
Max
4.73
4.18
2.90
4.10
3.41
0.23
0.60
0.71
0.46
0.65
2.73
2.38
2.14
2.79
2.33
7.62
6.54
4.50
7.26
5.06
SE = Standard error
Summary
Results confirm: Populations AR17056:N2025 and
CUBA117:S1520 are possible sources of WCR
resistance.
Four inbreds derived from populations
AR17056:N2025 (2) and CUBA117:S1520 (2) showed
significantly (P < 0.05) lower root damage ratings
than the resistant check.
Significant (P < 0.01) differences between entries
were found for leaf damage ratings. Some inbreds
and populations showed intermediate levels of
resistance against the first generation ECB.
Differences between entries for stalk damage
ratings and number of larvae were not significant.
Activities in 2004
Repeat experiment!
Screen more GEM germplasm!
Conduct diallel study!
Initiate recurrent selection
programs!
Acknowledgements
Mike Gray
Sue Ratcliffe
Kevin Steffey
And to the “rest” of crew:
Brad Engel
Ricardo Fonseca