Use of GEM Germplasm for Improving Drought Tolerance, Grain Mold, and Earworm Resistance Wenwei Xu

1. 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

2. 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

3. Constraints for Texas Corn Production • Water * Low rainfall in West Texas

4. More than 50% of Texas corn is produced in the irrigated fields.

5. Constraints for Texas Corn Production • Water * Low rainfall in West Texas * Declining water level of the Ogallala Aquifer * Increasing pumping costs

6. 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

7. Constraints for Texas Corn Production • Water • Heat stress *Leaf firing *Tassel blasting

8. Constraints for Texas Corn Production • Water • Heat stress • Corn earworm

10. Aflatoxin B1 (C17 H12 O6) Aspergillus flavus Constraints for Texas Corn Production • Water • Heat stress • Corn earworm • Aflatoxins

11. 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.

12. Materials and Methods - 71 GEM Breeding Crosses Drip Irrigation system for drought tolerance study

13. Stay green rating 1 = 100% green, 2 = 75%, 3 = 50%, 4 =25%, 5 = 0% green leaves

14. Corn Earworm Resistance • Larval penetration from ear tip toward the ear base • Ten ears per replication

15. Top 10 GEM breeding crosses for CEW resistance under well-irrigated conditions in Lubbock, TX in 2002-2003. Pedigree TROP% DTP CEW EL MOLD YBU ANTIG01:N16 50 78 4.8 21 2.7 138 ANTIG03:N12 50 76 5.5 20 3.3 148 BG070404:D27 50 83 5.5 19 3.7 127 BR51501:N11a 50 78 4.7 20 3.8 115 CML329:N18 50 75 5.1 22 3.0 122 CUBA84:D27 50 83 5.0 21 4.5 125 DK212T:N11a 50 75 5.3 19 4.0 106 DK888:N11a 50 78 4.4 18 4.5 101 DKXL380:N11a 50 76 4.5 18 3.7 81 SCROGP3:N1411a 25 75 5.1 18 3.3 119 B73 x Mo17 0 74 7.5 20 4.7 93 P34K77 0 70 5.9 18 3.7 146 P3223 0 77 4.9 18 3.3 169 Mean 75 6.8 19 4.8 110

16. Nine GEM breeding crosses with above average CEW resistance as measured by CEW ear penetration (cm) in 2002. Crosses CEW Crosses CEW Checks CEW BG070404:D27 4.0 DK888:N11a 4.2 B73 x Mo17 9.3 BR51501:N11a 4.6 ANTIG03:N12 4.8 P34K77 6.3 CUBA84:D27 5.0 DKXL380:N11a 5.1 P3223 6.3 BR51675:D27 5.2 DK212T:N11a 5.2 ANTIG01:N16 5.4

17. Top 10 yielding GEM breeding crosses under well-irrigated conditions in Lubbock, TX in 2002-2003. Pedigree TROP% DTP PHT CEW MOLD YBU ANTIG03:N12 50 76 229 5.5 3 148 ANTIG03:N1216 25 75 226 7.0 6 139 ANTIG01:N16 50 78 233 4.8 3 138 AR16026:N12 50 72 220 7.1 5 139 AR03056:N0902 25 73 224 7.2 5 132 CHIS775:N1920 25 74 225 7.0 6 133 CH05015:N1204 25 71 220 7.5 4 132 PRICGP3:N1218 25 76 241 7.4 5 138 SCRO1:N13 50 73 251 6.2 4 135 UR11002:N0308b 25 73 233 6.4 5 141 B73xMo17 74 229 7.5 5 93 P34K77 70 213 5.9 4 146 P3223 77 227 4.9 3 169 Mean 75 227 6.8 5 110

18. Lubbock College Station Location Irrigation Seasonal WW LI rainfall Etter 23.0” 18.6” 13.0” Halfway 23.6” 13.4” 7.0” Lubbock 16.0” 12.3” 8.0” Corpus Christi Dumas 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

19. WW (bu/a) LI (bu/a) % Entry ET HF LB LB HF MeanCKs 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 238 165 183 107 128 164 100 74 229 (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 98 70 231 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 95 76 240

20. Entry Yield Moist Aflatoxin PHT CEW bu/a % ppb cm cm (AR01150:N0406)F9A2 x B110 152 14 12 293 2 B110 x (SCROGP3:N1411a)F7 153 14 13 294 3 S1W x CML343 120 16 3 266 2 Tx202 x CML343 123 15 15 268 2 S2B73 x NC300 142 14 1 291 2 C3W64A x B110 136 15 66 265 4 C2A554 x B110 124 15 5 249 3 Mo18W x Mp313E (CK2) 125 17 13 292 3 Mp716 x Mp92:673 (CK3) 95 18 1 283 1 P31B13 (CK1) 154 13 14 267 1 Mean 132 15 14 277 2 CV% 11 3 ns 2 35 LSD 0.05 19 1   7 1 Yield and other agronomic traits at Mississippi State, MS in 2003 (Dr. W. Paul Williams, USDA-ARS)

21. 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 9279 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. Aflatoxin and Yield at Corpus Christi and Beeville, TX in 2003.

22. (SCROGP3:N1411a)-1

23. 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 W W 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 1007 4.3 4.3 B104 Y R 84 140 13 91 4 3.8 4.0 Mean 83 164 11 26 5 3.7 3.4 LSD 0.05 3 20 29 27 3 1.2 1.0 Days to pollen shedding (DTP), plant height (PHT), leaf firing (LF, %), CEW resistance, and stay green rating of selected inbred lines.

24. 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 (AR01150:N0406)F8A2, (FS8A(T):N1801)F7-2 (SCROGP3:N1411a)F8 • Continue inbred line development from other GEM breeding crosses.

27. 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):

28. Constraints for Texas Corn Production • Water • Heat stress • Corn earworm • Aflatoxins • Spider mites