Use of GEM Germplasm for Improving Drought
Tolerance, Grain Mold, and Earworm Resistance
Wenwei Xu
Agricultural Research and Extension Center
Texas A&M University
Lubbock, TX 79403
Presentation Outline
• Research rationale
• Evaluation of GEM breeding crosses
• Development of inbred lines using GEM breeding crosses
• Yield trials of top crosses from GEM inbred lines
Constraints for Texas Corn Production
• Water
* Low rainfall in
West Texas
More than 50%
of Texas corn is
produced in the
irrigated fields.
Constraints for Texas Corn Production
• Water
* Low rainfall in West Texas
* Declining water level of the Ogallala
Aquifer
* Increasing pumping costs
Constraints for Texas Corn Production
• Water
* Low rainfall in West Texas
* Declining water level of the Ogallala
Aquifer
* Increasing pumping costs
==> Drought tolerant corn
==> Early season corn
Constraints for Texas Corn Production
• Water
• Heat stress
* Leaf firing * Tassel
blasting
Constraints for Texas Corn Production
• Water
• Heat stress
• Corn earworm
9-M ar
4-M ay
1-Jun
Sample Date at Weekly Intervals
16-Nov
2-Nov
19-Oct
Heliothisvirescens
5-Oct
Lowest Abundance Year
C. 1995
1984 Abundance
600
Confidence Limit
400
800
200
14-yr Average
0
D. 1984
200
60
150
40
100
50
20
0
0
Average Number of Moths per Trap
Helicoverpa zea
21-Sep
7-S ep
24-Aug
10-Aug
27-Jul
13-Jul
29-Jun
15-Jun
Lubbock
4-M ay
18-May
20-Apr
6-Apr
B. 1988
23-Mar
A. 1984
9-M ar
16-Nov
2-Nov
19-Oct
Heliothisvirescens
5-Oct
Helicoverpa zea
21-Sep
7-S ep
2400
24-Aug
10-Aug
27-Jul
13-Jul
0
29-Jun
15-Jun
1-Jun
18-May
1600
20-Apr
6-Apr
23-Mar
Average Number of Moths per Trap
3200
Highest Abundance Year
1000
800
Constraints for Texas Corn Production
• Water
• Heat stress
• Corn earworm
• Aflatoxins
Aflatoxin B1 (C17 H12 O6)
Aspergillus flavus
Objectives of 2003 GEM Project
• To evaluate 71 GEM breeding crosses for drought
tolerance, grain mold resistance, and CEW resistance (2nd
year);
• To conduct yield trials of the top crosses of the inbred
lines derived from GEM germplasm (2nd year);
• To continue inbred line development from GEM breeding
crosses;
• To make top crosses of the
GEM inbred lines for 2004 trials.
==> Develop multiple stress
tolerant corn.
Materials and Methods - 71 GEM Breeding Crosses
Drip Irrigation
system for
drought tolerance
study
Stay green rating
1 = 100% green, 2 = 75%, 3 = 50%, 4 =25%, 5 = 0% green leaves
Corn Earworm Resistance
• Larval penetration from ear tip toward the ear base
• Ten ears per replication
Top 10 GEM breeding crosses for CEW resistance under wellirrigated conditions in Lubbock, TX in 2002-2003.
Pedigree
TROP%
ANTIG01:N16
50
ANTIG03:N12
50
BG070404:D27
50
BR51501:N11a
50
CML329:N18
50
CUBA84:D27
50
DK212T:N11a
50
DK888:N11a
50
DKXL380:N11a
50
SCROGP3:N1411a
25
B73 x Mo17
0
P34K77
0
P3223
0
Mean
DTP
78
76
83
78
75
83
75
78
76
75
74
70
77
75
CEW
4.8
5.5
5.5
4.7
5.1
5.0
5.3
4.4
4.5
5.1
7.5
5.9
4.9
6.8
EL
21
20
19
20
22
21
19
18
18
18
20
18
18
19
MOLD
2.7
3.3
3.7
3.8
3.0
4.5
4.0
4.5
3.7
3.3
4.7
3.7
3.3
4.8
YBU
138
148
127
115
122
125
106
101
81
119
93
146
169
110
Nine GEM breeding crosses with above average CEW resistance as
measured by CEW ear penetration (cm) in 2002.
Crosses
BG070404:D27
BR51501:N11a
CUBA84:D27
BR51675:D27
ANTIG01:N16
CEW
4.0
4.6
5.0
5.2
5.4
Crosses
DK888:N11a
ANTIG03:N12
DKXL380:N11a
DK212T:N11a
CEW
4.2
4.8
5.1
5.2
Checks
B73 x Mo17
P34K77
P3223
CEW
9.3
6.3
6.3
Top 10 yielding GEM breeding crosses under well-irrigated
conditions in Lubbock, TX in 2002-2003.
Pedigree
TROP%
ANTIG03:N12
50
ANTIG03:N1216
25
ANTIG01:N16
50
AR16026:N12
50
AR03056:N0902
25
CHIS775:N1920
25
CH05015:N1204
25
PRICGP3:N1218
25
SCRO1:N13
50
UR11002:N0308b
25
B73xMo17
P34K77
P3223
Mean
DTP
76
75
78
72
73
74
71
76
73
73
74
70
77
75
PHT
229
226
233
220
224
225
220
241
251
233
229
213
227
227
CEW
5.5
7.0
4.8
7.1
7.2
7.0
7.5
7.4
6.2
6.4
7.5
5.9
4.9
6.8
MOLD
3
6
3
5
5
6
4
5
4
5
5
4
3
5
YBU
148
139
138
139
132
133
132
138
135
141
93
146
169
110
Yield Trials of Top Crosses of GEM Lines
• 32 single crosses: 15 GEM lines x public lines
• 4 checks: P34K77, P3223, Garst 8348 and Garst 8285
• 3 locations in TX: Etter, Halfway, and Lubbock
• Well-irrigated and limited-irrigation conditions
• Two-row plots (15’ x 40” or 15 x 30”), 2 reps
Location
Irrigation
Seasonal
WW
LI
rainfall
Etter
23.0”
18.6”
13.0”
Halfway
23.6”
13.4”
7.0”
College Station
Lubbock
16.0”
12.3”
8.0”
Corpus Christi
Dumas
Lubbock
WW (bu/a)
HF LB
LI (bu/a)
LB
%
Entry
ET
HF Mean CKs DTP PHT
(AR01150:N0406)F8A1 x B110
267 224 175
92 144 181 110 76 243
(AR01150:N0406)F8A1 x B113
236 214 170
98 124 169 103 73 227
(AR01150:N0406)F8A2 x B110
260 252 193
88 142 187 114 76 247
(AR01150:N0406)F8A2 x B113
238 165 183 107 128 164
(AR03056:N0902)F8-1 x B110
256 198 171 109 101 167 102 74 212
(FS8A(T):N1801)F7-2 x B113
229 207 163
93 128 164 100 74 231
(FS8A(T):N1801)F7-2 x B110
259 229 208
73 159 186 113 74 242
(FS8B(T):N11a)F7-2 x B110
188 231 176 102 142 168 102 75 248
B110 x (SCROGP3:N1411a)F7
197 220 183
93 124 163 100 75 257
B110 x (SCROGP3:N2017)F7
250 197 171
96 120 167 102 76 242
P34K77
226 173 155 120 130 161
Garst 8348
258 159 182 110 115 165 100 72 229
P3223
258 207 174 117 117 175 107 77 237
Garst8285
216 195 151 114 101 155
100 74 229
98 70 231
95 76 240
Yield and other agronomic traits at Mississippi State, MS in
2003 (Dr. W. Paul Williams, USDA-ARS)
Entry
Yield Moist Aflatoxin PHT
bu/a
%
ppb
cm
(AR01150:N0406)F9A2 x B110 152
14
12
293
B110 x (SCROGP3:N1411a)F7 153
14
13
294
S1W x CML343
120
16
3
266
Tx202 x CML343
123
15
15
268
S2B73 x NC300
142
14
1
291
C3W64A x B110
136
15
66
265
C2A554 x B110
124
15
5
249
Mo18W x Mp313E (CK2)
125
17
13
292
Mp716 x Mp92:673 (CK3)
95
18
1
283
P31B13 (CK1)
154
13
14
267
Mean
132
15
14
277
CV%
11
3
ns
2
LSD 0.05
19
1
7
CEW
cm
2
3
2
2
2
4
3
3
1
1
2
35
1
Aflatoxin and Yield at Corpus Christi and Beeville, TX in 2003.
Hybrids
Yield (bu/a)
Aflatoxin
BV
CC
(ppb)
S1W x CML343
73
44
49 de
Tx202 x CML343
68
41
54 cde
S2B73 x NC300
92
79
31 e
C3W64A x B110
78
76
42 e
C2A554 x B110
72
84
59 cde
NC340 x S1W
71
34
96 bc
(AR01150:N0406)F9A2 x B110
83
83
88 bcd
B110 x (SCROGP3:N1411a)F7
86
59
240 a
P31B13 (RM 117)
85
92
161 ab
DK XL296
74
57
47 de
Mean
78
65
87
LSD 0.05
14
8
Rainfall during the crop season was 11.68 and 7.8 inches at BV and CC. At BV, 4.72-inches of total rainfall was received from
Hurricane Claudette on July 16, 40 days after flowering. When the first hybrid was at mid-silk, corn kernels colonized with a
high aflatoxin-producing isolate of A. flavus (NRRL3357) were distributed between all rows.
(SCROGP3:N1411a)-1
Days to pollen shedding (DTP), plant height (PHT), leaf firing (LF, %),
CEW resistance, and stay green rating of selected inbred lines.
Lines
Ear
DTP PHT LF LF CEW Stay Green
K C
LB
HF
LBD
HFD
(AR01150:N0406)-A1
Y W
83 161
0
20
6
3.0
3.8
(AR01150:N0406)-A2
Y R
83 164
2
0
5
3.5
3.8
FS8A(T):N1801-1
Y W
79 133
3
0
7
4.8
2.8
SCROGP3:N1411a-1
Y W
85 191
0
0
4
2.0
2.0
S1W
WW
85 179
0
0
2
2.8
2.8
C3S1B73-3
Y R
83 148 18
6
2
5.0
4.0
B76
Y R
83 156
0
0
6
3.3
3.3
B73
Y R
84 188
40 100
7
4.3
4.3
B104
Y R
84 140
13
91
4
3.8
4.0
83 164
11
26
5
3.7
3.4
29
27
3
1.2
1.0
Mean
LSD 0.05
3
20
Future Research Effort
• Top crosses were made between GEM inbred lines with
Holden’s lines (LH185, LH198, LH200, LH247, and LH283)
and public lines for 2004 field trials.
• Release proposals for the inbred lines:
(AR01150:N0406)F8A1
(FS8A(T):N1801)F7-2
(AR01150:N0406)F8A2,
(SCROGP3:N1411a)F8
• Continue inbred line development from other GEM
breeding crosses.
9-M ar
5-Oct
Sample Date at Weekly Intervals
5-Oct
16-Nov
2-Nov
19-Oct
Heliothisvirescens
21-Sep
Lowest Abundance Year
2400
1987 Abundance
600
Confidence Limit
14-yr Average
400
800
200
0
0
D. 1984
200
60
150
40
100
50
20
0
0
Average Number of Moths per Trap
Helicoverpa zea
7-S ep
24-Aug
10-Aug
27-Jul
13-Jul
29-Jun
15-Jun
1-Jun
Halfway
4-M ay
18-May
20-Apr
6-Apr
B. 1988
23-Mar
A. 1987
9-M ar
16-Nov
2-Nov
Highest Abundance Year
19-Oct
Heliothisvirescens
21-Sep
Helicoverpa zea
7-S ep
24-Aug
10-Aug
27-Jul
13-Jul
1600
29-Jun
15-Jun
1-Jun
18-May
4-M ay
20-Apr
6-Apr
23-Mar
Average Number of Moths per Trap
3200
1000
C. 1993
800
Water-level changes in the
High Plains (Ogallala) aquifer
from 1980 to 1996:
• Ogallala aquifer covers 8
states: CO, KS, NE, NM, OK,
SD, TX, WY.
• Water level has declined:
0.25’/year in 1940-80.
0.18’/year in 1980-96.
* Irrigated acres by ground
water (in millions):
1949 1959
1969 1978 1980 1990
2.1
9.0
6.1
12.9
13.7
95%
Constraints for Texas Corn Production
•
•
•
•
Water
Heat stress
Corn earworm
Aflatoxins
• Spider mites