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2004 PROGRAM ACCOMPLISHMENTS AND HIGHLIGHTS

Germplasm releases and development:

• Nine GEM lines from the Ames program are recommended for release to GEM Cooperators for 2005 based on 2 year trial data that included yield, acceptable standability, good yield/moisture ratio (Y/M), and/or favorable Value-Added Traits (VAT).
• Seven lines derived from 50% tropical germplasm were recommended from the Raleigh, NC program (see SCA report, and oral presentation by Goodman)
• Two stress tolerant inbreds (Tx204 and Tx205) derived from the GEM breeding cross (AR01150:N0406) were publically released from Texas A&M (see SCA report by Xu).
• University of Wisconsin inbred “UW EX01,” derived from AR17026:N1019 with outstanding silage productivity and milk production per acre is projected for release in 2005 (see SCA report by Coors).
• Inbred GEMS-0002 manuscript for Crop Science registration was submitted by R.C. Pratt, L.M. Pollak, and K.T. Montgomery.
• A cooperative study on breeding methodology was begun with the University of Delaware (UDEL) and GEM Ames.  Two breeding crosses (one Stiff Stalk and one non-Stiff Stalk) were grown to initiate a breeding methodology study comparing the GEM protocol, mass selection, and a modified single seed descent procedure.

Pathology/Entomology:

• Pathology and entomology collaboration from the private and public sectors included extensive data collection on GEM lines and breeding crosses for anthracnose, Northern Leaf Blight races 1 and 2,  Southern Leaf Blight, Stewart’s Wilt, Goss’s Wilt, Gray Leafspot, common and southern rust, Fusarium ear rot, Aspergillus, European Corn Borer, Corn ear worm, and corn root worm.  Public Cooperator Reports are available at this meeting.  Special recognition and thanks to the extensive efforts of private GEM Cooperators Pioneer Hi-Bred International, and Professional Seed Research.  Results from the private sector will be made available in the near future on our web site.
• In a cooperative study of germplasm from Ames and Raleigh with USDA-ARS in MS, four 50% tropical derived Raleigh, NC inbreds and five 50% tropical breeding cross show promise for Aspergillus ear rot,  aflatoxin resistance, and adaptability  (see SCA report by Clements)
• Collaboration with Raleigh, NC for Fusarium/fumonisin evaluation with Jim Holland and Major Goodman identified potential sources of resistance in 5 Midwest developed GEM lines grown in NC Fusarium nurseries.  NC lines having southern rust resistance were increased in the Ames nursery for future potential sources of resistance.
• Martin Bohn’s research identified consistency over 2 years for sources of germplasm with resistance to first generation (ECB1), and second generation (ECB2) European Corn Borer.  The results for Western Corn Rootworm (WCR) were less consistent due to the intense levels of WCR in 2004.  (See SCA report by Bohn).

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Quality Traits:

• Cooperation between Ames and Raleigh included NIR analysis resulting in identification of two inbreds from NC set “GEMWIN” with high protein. 
• Among the nine recommended Ames lines for 2005 three had above average protein content relative to B73, and one line had good oil content of 4.7%.  Two inbreds had interesting starch thermal properties.
• Mark Campbell’s first year trials were encouraging for identifying GEM topcross high amylose hybrids outperforming a commercial high amylose check (see SCA report by Campbell).
• Paul Scott’s research identified a previous UDEL line DKXL212:N11a-139-1-1-B-B-B, with a well balanced index of amino acids for (Met + Trp + Lys + 0.5 Thr).  (See SCA report by Scott).

Ames Location Highlights:

• Agronomic data migration to Plant Information Sharing Manager (PRISM) data base is complete.  Also related nursery records and pedigrees have now been migrated.

• Ninety-seven experimental hybrids were identified from Midwest yield trials in 2004, having better yields than the mean of the 5 check hybrids.  Twenty-six of these were retest hybrids and 71 from first year trials. 

• GEM breeding crosses (175) were evaluated for phenotypic traits and Midwest adaptability through the collaborative efforts of Ames, Clinton, IL (Golden Harvest), and the UDEL.  Southern observations of breeding crosses were made in Raleigh, NC, and in Lubbock, TX (both reports are presented in Public Cooperator Reports).

• Approximately 14,707 plots (approximately 2,112 entries including checks) were managed or coordinated from the Ames location in 2004.  This was about a 60% increase over 2003 trials.

• Approximately 7,000 nursery rows were grown in Ames in 2004.  This was a 25% increase from 2003.

• Approximately 1,000 rows were planted in isolations on 4 testers, or in hand crossing blocks to make new topcrosses or retest hybrids.

• Two new GEM Cooperators joined GEM from the private sector in 2004.  BASF Plant Science, and Agrotuniche LTD, from Chile.

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GEM Survey:

During the June TSG meeting it was agreed that a web-based survey should be conducted to evaluate the utility of GEM material, and how GEM can better meet the expectations of the GEM Cooperators.  A TSG sub-committee developed a series of about 20 questions with inputs from all TSG members.  The document was approved and distributed this fall to GEM Cooperators, and other breeders and individuals from related disciplines who had familiarity with GEM and/or exotic germplasm research.  We were happy to receive more than 80 responses.   The results of the survey will be presented at the December 2004 Cooperator Meeting in Chicago and will be submitted for publication.

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GEM Line Recommendations for Midwest for 2005 Release:

Nine GEM lines were selected in 2004 having 2-years of favorable data for yield, Y/M, and resistance to stalk and rot lodging.  At least two of these lines have enhanced levels of protein, and/or interesting starch thermal properties.  The lines are from a diverse group of races from accessions originating from Barbados, Chile, Mexico, Thailand, Dominican Republic, Uruguay.  Data presented at the December 2004 Cooperators covers 2-years of performance on several testers.  A handout will be distributed with additional agronomic information such as hybrid ear height, maturity, and flowering date.

Table 1. Recommended Ames GEM Lines for 2005 Release

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Raleigh, NC Location Highlights (from Dr. Major Goodman):

GEM Yield Trial Plots Coordinated by NC State (all 50%-tropical)    

Standard Plots Grown by 15 cooperators:                                                                    9,200

(11 company locations, 2 other universities, 2 USDA-ARS sites)

Standard Plots Grown by NC State (5 locations):                                                         6,342

Additional GEM Plots (all at NC State locations for tester,

CML-type line, GEM inbreds, and breeding cross evaluations):                                    6,712

TOTAL GEM YIELD TRIAL PLOTS COORDINATED BY NC STATE:                    22,234

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GEM Nursery Rows at NC State:

   Selfing:                                                              1,270

   Pairs (most in winter nursery):                               500

   Isolation:                                                              850

17 new Breeding Crosses are being worked.

From two-years’ of direct yield-trials of Breeding Crosses the following looked best (rank order):

 1. PE11:S11a (BR51501)                   11. CML329:N18                 

 2. CL‑00331:N18                               12. BG070404:D27               

 3. FS8B(S):S03                                  13. PE27:D27 (BR51675)         

 4. BR105:S16                                     14. CUBA84:D27                 

 5. DKB830:S19                                  15. PE01:S02                   

 6. FS8B(T):N11a                                16. RN07:N20                   

 7. RN07:S20 (BR51721)                    17. CUBA164:D27                

 8. SE32:N11c (BR52051)                   18. MDI022:N21                 

 9. PASCO14:S11a                             19. FS8B(T):N18                

10. GUAT209:N11c                            20. SCR0GP3:N20                

                                                            21. CL‑G1607:S18               

Perhaps most important, the following were identified as likely being of very low priority (ranked from worst to merely bad):

 1. CML325:N13                     14. NEI9008:S17a              

 2. CHIS462:N08a                   15. CML247:N17c               

 3. CML247:N17a                   16. CML323:S17a               

 4. CML247:N18                     17. NEI9008:S17b              

 5. CUBA117:S15                   18. CHIS740:S14               

 6. CML247:N17b                   19. CML323:S17b               

 7. SANM126:S12                   20. NEI9008:S17c              

 8. DK888:S08a                       21. NEI9008:N08               

 9. FS8B(S):S17b                    22. CML287:N13                

10. DKXL370:S08a                 23. DKXL370:S08c              

11. GUAD05:N06                   24. CL‑G1501:S17b             

12. MDI022:S21                      25. PASCO14:S21               

13. DKXL380:S08a                 26. NEI9004:S28               

Approximately 300 plots were planted for fusarium at Pioneer’s Camden, NC location.

Gray leaf spot was scored for 1400 GEM plots across 3 NC locations.

About 1,000 new GEM topcross families were produced in 2004.

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PUBLIC COOPERATOR WITH SPECIFIC COOPERATOR AGREEMENTS (SCA) IN 2004:

Eleven university and three USDA-ARS projects were funded in 2004 for a total of $194,923. 

Table 2. Public Cooperators Supported In 2004

                                                                                                            Total         $194,923

A short summary of key highlights from each SCA report is included below.  Please see the complete report under Public Cooperator Reports for details about methods, pedigrees, and data tables.

Martin Bohn, University of Illinois: Evaluation of GEM germplasm for multiple insect resistance and fumonisin concentration. The objective of this project (now in second year) is to evaluate and study the genetic basis of resistance of GEM lines and breeding populations for resistance to Western Corn Rootworm (WCR), first and second generation of European Corn Borer (ECB 1 and ECB2 respectively), and the association between insect resistance and fumonisin concentration due to Fusarium sp. Results in 2003 were very encouraging for identifying lines having resistance to root damage (RDR) due to WCR.  In 2004, levels of WCR were very intense and all material (including resistant check, NGSCDRW1) appeared more susceptible than in 2003 (lowest RDR rating 2.14 for GEM inbred AR17056:N2025 Select # 2-B-B).  For ECB, significant differences were found for levels of leaf damage (LDR), and stalk damage (SDR).  Across the three experiments conducted for lines and populations, GEM derived genotypes were as resistant as the checks for ECB1 LDR (check=CML333) and ECB2 SDR (check=De811).   Bohn’s results shown in Table 1 identify interesting sources of temperate and tropical GEM germplasm for lines and breeding crosses for ECB1, ECB2, and possibly for WCR.  The results for fumonisin analysis are pending.

Mark Campbell, Truman State University:  Yield and quality evaluation of Amylomaize VII(>70% amylose) test crosses, continued development of Amylomaize VII inbreds using GEM and related studies. The objective of this study is to develop GEM lines having amylose content of 70% referred to as Amylomaize VII.  Previous studies at Truman State University identified sources of GEM germplasm having modifier genes for amylose content, specifically from GUAT209:S13.  Other non-GEM exotic sources with modifiers include NCR 5357 Zia Pueblo, and Cochiti Pueblo NRC 5298.  Development of amylomaize VII corn general involves two steps.  First germplasm is converted with the recessive amylose extender (ae) allele and secondly, quantitative modifier genes must be fixed as well. Until now, most, if not all amylomaize VII germplasm is owned privately.  The only public source, as far as we know, is at Truman State University in which amylomaize VII germplasm has been developed almost entirely using GEM germplasm or from exotic plant introductions.  In 2004, the first yield trial evaluation was made using 2 proprietary Amylomaize lines as testers in both stiff stalk and non-stiff stalk background.  Yield trials were conducted in Ames, IA (with on site GEM support), and at the University of Missouri’s Greenley Memorial Research Center near Novelty, MO.  A third location of yield data is pending from Kirksville, MO.  Results from the 2 locations have been very promising with some GEM hybrids outyielding the proprietary Amylomaize VII check (although not always significantly).  The best crosses were those between non-stiff stalk amylomaize GEM lines and the proprietary stiff stalk tester (n x s).  Some of the GEM lines that are designated as S may also contain some percentage of non-stiff stalk background coming from the ae donors.  This may explain why some of the S x S type crosses yielded relatively well.  Research is continuing to analyze the amylose content of F2 harvested seed among the promising GEM crosses.

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Marcelo Carena, North Dakota State University: EarlyGEM: Incorporating GEM elite lines in early maize: Phase II The objectives of this project are to determine the suitability of 25% GEM backcross lines for use as grain hybrids in the northern Corn Belt.  In addition, obtain 25% GEM genotypes adapted to North Dakota (Phase I accomplished); top cross BSSS GEM genotypes (BC1:S2) to a commercial tester and evaluate them across northern environments (Phase II); identify and incorporate top inbreds into our inbred development program (Phase III); and determine their potential for release (Phase IV). Selection within original GEM lines was performed not only for earliness but also for disease resistance and other visual traits we could identify while making crosses. Only the best plants were selected for crossing. Stiff Stalk donors (CUBA117:S1520-388-1-B or GEM3 in our designation, CHIS775:S1911b-B-B or GEM13, CUBA117:S15-372-1 or GEM12, and AR16026:S17-66-1-B or GEM21) were identified for backcrossing in 2003.  Sixty-two rows were planted in 2003 breeding nursery in order to produce BC1 populations. F1s were planted side by side with the recurrent parent (early adapted ND lines). We have discarded later-flowering plants and harvested each BC1 plant from each cross separately.  GEM13 x ND2000 showed good adaptation based upon its height and flowering time (67 days after planting). However, F1 plants were not uniform and seedling vigor was below average. GEM12 was also discarded based on poor agronomic traits in the hybrids.  Sixty seeds from each BC1:S0 ear were planted in 2004 breeding nursery on May 7. We decided to make a second round of screening for additional BC1:S0 generations obtained with ND2000 as recurrent parent.  The target was to obtain 100 BC1:S1 ears per population. Rows were screened for seedling vigor (0-9 scale) and checked for uniformity. Plants with below average agronomic characteristics were discarded. Ears were hand-harvested in October 2004. Shelling of individual BC1:S1 lines was performed in November 2004.  GEM S1 selections will be planted across three locations for early generation visual selection in 2005. These locations will include breeding and disease nurseries. S1 selections will be advanced to elite S2 materials and S2 seed from top selected S1 selections will be crossed to LH176xLH177 private tester in the 2005-2006 winter nursery if funds are available or 2006 summer nursery.

Michael Clements, USDA-ARS, Mississippi State, MS:  Evaluations of maize accessions for resistance to Aspergillis ear rot, aflatoxin contamination in grain, and leaf feeding by Southwestern corn borer. The objective of this study is to assess GEM lines and breeding crosses for resistance to aflatoxin accumulation, resistance to Aspergillus ear rot, leaf feeding from southwestern corn borer (SWCB), and for agronomic characteristics suitable for the southern U.S.  Although this is the first year of study, preliminary aflatoxin screening of GEM material began in 2003.  Aflatoxin concentration in grain was not affected significantly by replicates (P= 0.2392), but was affected significantly by genotypes (P<0.0001) in 2003.  Treatment means for aflatoxin concentration in grain among GEM lines and experimental checks ranged from 9 to 2147 ng g^-1 (mean 546 ng g^-1).  Aflatoxin concentration was least from the resistant check, Mp313E.  Aflatoxin concentration from another resistant check, Tuxpan, and four GEM lines developed in Raleigh, NC did not differ significantly (P>0.05) from Mp313E.  All four of these lines had Aspergillus ear rot severity that did not differ significantly (P>0.05) from the resistant check, Mp313E, in 2003 and 2004.  (See table 1 for full pedigrees of GEM lines).  All four lines have agronomic characteristics that are acceptable for southern environments.  Aflatoxin concentration in grain from five breeding crosses (CUBA84:D27, BG070404:D27, ANTIG01:N16, CUBA164:D27, and BR51403:N16) did not differ significantly (P>0.05) from Mp313E x Mo18W.  All five of these breeding crosses had severity of Aspergillus ear rot that did not differ significantly (P>0.05) from Mp313E x Mo18W in 2003 and 2004.  GEM lines will be evaluated for agronomic characteristics and resistance to aflatoxin accumulation in grain as testcrosses developed with commercial inbreds Holden’s LH195 and LH210 in 2005.  Ear to row and recurrent selection programs are currently underway with several of the most promising lines and breeding crosses.  A poster presentation of this work was presented at the Aflatoxin Elimination Workshop in October by Clements.

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Jim Coors, University of Wisconsin:  Development of inbreds, hybrids, and enhanced GEM breeding populations with superior silage yield and nutritional value. The successful identification of GEM lines and their further development for silage yield and quality at the University of Wisconsin has proven successful over the years. Results from 2004 have been particularly encouraging.  Field trial results for 4 groups of experiments designated GEMNEW, GEMADV, GEM198, and GEM244 were presented with interesting results for yield (nutritional quality results are expected next month).  Two lines from GEMNEW were identified with superior forage yields above 9 tons/acre with high dry matter content and were considered adapted to Wisconsin conditions.  One of these lines, FS8B(T):N11a-322-1 x LH198, was a GEM recommended line for grain yield and was released to GEM Cooperators in spring 2004.  DK212T:S11 F2S4 2111-01 x LH185 was released from the Raleigh, NC program and made available publically in 2003.  There are a large number of topcrosses in GEMADV that have considerable potential. One hybrid in particular, AR17026:N1019-65008-2-3-2-1-1 X LH244, had the highest mean forage yield in the trial.  This topcross is designated “UW EX01” in the 2004 UW Corn Extension report, which can be accessed via http://corn.agronomy.wisc.edu. We had similar results for AR17026:N1019-65008-2-3-2-1 X HC33 in 2003. We will formally initiate release of AR17026:N1019-65008-2-3-2-1-1 in December. In 2004 we increased seed quantities for crosses of AR17026:N1019-65008-2-3-2-1-1 with HC33, LH198, LH244, LH332, and TR7245 so that those interested can evaluate this GEM inbred in multiple testcrosses. In 2004, we continued our new breeding effort for the GEM Quality Synthetic (GQS), developed from GEM breeding populations CUBA164:S1517, CUBA164:S15, and CUBA117:S1520. Since GQS is approximately 75% Stiff Stalk, inbred lines from GQS may well produce silage hybrids with high forage yield as well as superior nutritional quality when crossed to inbred lines from our Wisconsin Quality Synthetic, which is a non-Stiff Stalk breeding population. We will continue breeding GQS using the same S2-topcross system used for WQS.

Major Goodman, North Carolina State University: Conducting, coordinating, and developing inbreds from the Southern GEM trails using 50%-tropical maize germplasm. The objectives of this project include the development of families from 50% tropical germplasm, and 8 sub-objectives described in the full report.  In 2004, breeding families were evaluated for per se yield performance in NC and it was concluded that most GEM families are poor candidates for future development in the south (based on 2003 and 2004 data).  Some of the more favorable breeding crosses performed within 10% of the yield of adapted check hybrids and are listed in the report.  Equally important was the identification of breeding crosses that should not be used for development for the south.  Research in the evaluation of testers for the south is continuing.  The stiff stalk tester FR615xFR697 is acceptable for the stiff stalk side but non-stiff stalk Midwest lines are not acceptable for the south.  The recent identification of TR7322xNC320 seems to be an acceptable alternative for non-stiff stalk.  New GEM lines presented in tables 1 and 2 derived from about nine 50% tropical breeding crosses are being made available to GEM Cooperators through Major Goodman.  Other work at Raleigh included disease evaluations for grey leafspot, and southern rust.

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Jim Hawk, University of Delaware:  Inbred line development and hybrid evaluation in GEM breeding crosses. The objective of this project is to identify GEM breeding crosses and lines with desirable agronomic characteristics, resistance to abiotic and biotic stresses, and high consistent yield performance.  UDEL participated in a breeding cross evaluation screening with the GEM location in Ames, IA, and Golden Harvest in Clinton, IL.  One hundred seventy three GEM breeding crosses were evaluated for adaptability, maturity, flowering synchrony, standability, plant and ear height, pest resistance, stay green, grain quality, and drydown.  Results of this study is important for future selection of GEM breeding crosses for development.  Inbreeding was also initiated on ten new Stiff Stalk and two non-Stiff Stalk GEM breeding crosses. Two breeding crosses (one Stiff Stalk and one non-Stiff Stalk) were grown to initiate a breeding methodology study comparing the GEM protocol, mass selection, and a modified single seed descent procedure.  This study is a Cooperative project with GEM in Ames.  Yield tests were conducted on 235 Stiff Stalk lines crossed to LH185 and/or a Pioneer non-Stiff Stalk tester and 103 non-Stiff Stalk lines crossed to a Pioneer Stiff Stalk tester at two irrigated and one dryland locations in Delaware (two reps/location), one location (one rep) at Ames, Iowa and one location (one rep) at Mt Vernon/Fort Branch, Indiana. The lines were also advanced and evaluated per se for agronomic performance. Yield test results are listed in (Tables 3-12).  Several top crosses were identified from derived lines of DK212T:S0620, DK212T:N11a10, and CUBA164:S1511b that had competitive performance, maturity, and standability relative to the checks. The top 10-20% lines will be advanced. S₂ lines from selected breeding crosses will be test crossed and hybrid evaluations will be conducted summer 2005. 

Bruce Hibbard, USDA-ARS, Columbia, MO:  Breeding for corn rootworm resistance in maize. The objective of this research (in second year) is to develop elite populations useful for derivation of corn rootworm (CRW) resistant lines to serve as a basis of future molecular genetics research.  Based on 2003 results, four populations were chosen for extraction of lines for CRW resistance and good agronomics.  These included UR13085:N0215 (4 families), CHIS775:N1912 (14 families), DK212T:S11 (10 families), and BR52051:N04 (7 families)-all lines were increased in 2003-4 winter nursery, and additional subfamilies were evaluated from these materials in 2004 in 3 reps in a maize trap crop field with additional eggs placed mechanically.  The combination of natural infestation and manual infestation provided an extremely high level of root worm pressure in 2004, and overall the level was higher than desired (nearly 2.5 nodes of damage on controls).  The DK212T:S11 population had the highest proportion of roots with damage less than the control.  Each of the other populations had plants with reduced damage compared to the rating of the susceptible check (2.48).  Selected entries in each population were bulk random mated, and some selfed for inbred development.

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Manjit Kang, Louisiana State University: Identifying resistance to infection by Aspergillus flavus and Fusarium in GEM breeding crosses and advanced breeding lines. The purpose of this research was to identify sources of resistance to infection by Aspergillus flavus and Fusarium verticillioides in selected GEM breeding crosses and advanced breeding lines.  A total of 30 breeding crosses and 41 breeding lines were planted in two replications of a randomized complete-block design on April 23, 2003 at the Ben Hur Plant Science Farm near Baton Rouge, LA.  In 2004, the same 30 breeding crosses and 41 lines were planted again for a second year of study.  Results in the report are for 2003 only, and 2004 data is projected to be available with 2 year data analysis in January 2005.  The media-free incubation technique developed by Li and Kang (in press) was used to evaluate genotypes for percent kernel infection (PKI). A total of 144 kernels per replication was evaluated using 48-well culture plates. Surface-sterilized kernels were placed in wells of the plates and plates were sealed with cellophane tape to prevent any contamination.  After a 10-day incubation period, the number of infected kernels was recorded.  Some of the most resistant breeding crosses to Aspergillus ear infection included ANTIG03:N12, UR10001:S1813, and AR16035:S19.  The most resistant lines included DKXL370:N11a20-604-1, and 2152-03 DK888 S11 F2S4.  It was also of interest that two lines were relatively resistant and derived from one of the more resistant breeding crosses, UR10001:S1813-159-3, and UR10001:S1813-257-1.  All of the lines had greater resistance to Aspergillus ear rot than the resistant check, GT-MAS:GK.  Lines having the most resistance based on PKI will be analyzed for aflatoxin content.

Richard Pratt, Ohio State University: Optimization of protein and oil value-added traits and their combination with elite Ames and southern GEM lines. This project was initiated in 2003.  High protein and high oil GEM breeding lines, and their sister lines or other closely related lines with desirable agronomic performance, were identified by examination of existing data sets.  Selected lines arising from both the northern (ISU) and southern GEM (NC State) projects were selected and evaluated at two locations in 2003.  Several lines with high trait values e.g. 14.5% protein in line 02GEM00305 PE001n16F2S2-431-B, and their crosses to other desirable lines, were selected for further examination in the 2004 nursery.  Controlled self-pollination of the F₁s was performed to provide new high-trait X high trait F₂ populations and high-trait X high agronomic performance F₂ populations.  These populations will provide high selectable variation for 1) a favorable balance of agronomic and grain quality traits and 2) extreme trait expression per se.

Selected lines were planted in the field near Wooster, Ohio in replicate tests.   Controlled pollinations were made to provide uniform grain samples and to produce F₂ populations for further trait enhancement. Grain samples have been harvested and dried but compositional analysis has not been performed.  A manuscript was submitted for registration of the inbred GEMS-0002.   Pratt, R.C., L. M. Pollak, and K. T Montgomery. 2004.  Registration of Maize Germplasm Line GEMS-0002.  Crop Science (Submitted).

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Paul Scott, USDA-ARS, Ames, IA:  Amino acid analysis of GEM germplasm. The objective of this study is to determine the environmental stability of the amino acid content

of selected GEM lines, and evaluate the microbial analysis method as an economically feasible method for amino acid determination.  In a preliminary study in 2003, various GEM lines were identified having amino acid content greater than the “normal checks” B73, Mo17, and B73xMo17.  Some lines in 2003 also outperformed the known “high check” line for lysine (B45o2) and methionine (B101).  In the follow-up 2004 study 29 GEM lines outperformed all the normal checks for methionine, one GEM line outperformed the normal check for Tryptophan, and one for lysine.  Encouragingly, one GEM line, DKXL212:N11a-139-1-1-B-B-B, was the top ranked sample in the index ranking (Met + Trp + Lys + 0.5 Thr), outperforming both of the high ranking checks.  This line has unusually well-balanced amino acid content and will be particularly interesting for further study.  Correlation coefficients were highly significant for amino acid content among the 2 years and range were 0.66**, 0.64**, and 0.58** for Lys, Met, and Trp respectively.   Other parts of this project now in progress include variability in F2 families, screening more GEM lines, and methods comparison of microbial analysis with AOAC standard method.  Other amino acids of interest in this study include tryptophan, threonine, leucine, and proline.  

Margaret Smith, Cornell University: Anthracnose stalk rot resistance from exotic maize germplasm. The objective of this study is to develop temperate-adapted maize inbreds with both anthracnose stalk rot resistance and good yield potential from GEM breeding populations.  This study reports the latest results of a multi-year inbred development effort.  Inbreds at the S6 level were previously identified and selected with anthracnose resistance greater than known resistant check inbreds.  In 2004, the inbreds, and hybrid test crosses with public and Holden’s testers were further evaluated for resistance and test cross performance.  Promising inbreds were derived from 4 temperate 25% exotic germplasm populations: FS8B(T):N1802, CH04030:S0906, AR01150:N0406, and GOQUEEN:N1603.  From these populations, a total of 27 lines have been selected based on per se anthracnose stalk rot resistance and testcross yield potential.  The major accomplishment for this project to date is the development of advanced breeding lines (nearly finished inbreds) that are showing strong resistance to anthracnose stalk rot.  Resistance in the best of these materials is comparable to that available in currently released U.S. inbreds.  Simultaneous selection for agronomic performance has identified the better fraction of these resistant selections in terms of yield, maturity, and standability.  A few lines have emerged that appear to have good resistance, both per se and in testcrosses, and good yield potential and agronomic quality.

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Dennis West, University of Tennessee: Breeding lines with exotic germplasm. The objective of this research is to develop new parental maize lines with desirable milling and grain quality characteristics from GEM populations.  In 2004, 793 experimental GEM hybrids were evaluated in 16 yield trials in Tennessee.  These hybrids were crosses between GEM lines and adapted germplasm.  Results from this single replicate trial at Knoxville, TN are shown in table 1.  Several experimental hybrids were competitive with commercial check hybrids included in these trials.  An experimental hybrid in trial W87 (CHIS775:N19 F1S3 x T8) yielded 20 bu/a more than the average of 4 check hybrids.  The best lines from these GEM accessions will be selected for further testing and incorporation into breeding for new value-added parental lines.  Inbreeding and selection was continued in populations resulting from crosses between GEM lines identified in previous trials.

Wenwei Xu, Texas A&M University: Characterization and use of GEM breeding crosses for drought tolerance, grain mold resistance, and corn earworm resistance. The objective of this project is to continue research efforts for: 1) Multi-location yield trials of the topcrosses between the GEM inbred lines and Holden’s (LH185, LH198, LH200, LH247, and LH283) or public tester lines; (2) advancing and characterizing new inbred lines developed from GEM breeding crosses; (3) performing first-year field evaluation of 41 new GEM breeding crosses for drought tolerance, grain mold resistance, and CEW resistance; and (4) characterizing the 16 new recommended lines(released in 2004 to GEM Cooperators) for drought, heat tolerance, and Corn ear worm (CEW) resistance.  Summarizing results: Among the 60 crosses between GEM lines and public lines, Tx204 x B110 and Tx205 x B110 were the best.  Their yield average yield was 213 and 208 bu/a, 9-10% higher than the check means (Table 2).  Inbred lines Tx204 and Tx205 were developed from AR01150:N0406 from my program at Texas A&M in Lubbock.  Inbred lines Tx204 and Tx205 were officially released in August 2004, and are available from Wenwei Xu royalty free. Tx204 has white cobs, while Tx205 has red cobs and shows a better combing ability.  Both lines have above-average early vigor, stress tolerance, upright and dark-green leaves, green silks, 3-5 primary tassel branches, 16-18 rows of semi-dent yellow and long kernels.  Their maturity, plant and ear height are similar to B73. Breeding crosses were evaluated for yield and numerous agronomic traits relating to stress, insect, and grain mold resistance.  A combined analysis of all data from three water treatments was used to make an imperial selection index.  The best five breeding crosses are UR13085:N0204, CML323:N15, BR52051:N0417, UR13010:N0613, AR16026:N1210, AR13026:N08a04, and GUAT209:N11c (Tables 5-7).  Results for evaluation of the 16 released GEM lines indicated that all of these lines were susceptible to CEW.  All lines except the AR03056 lines had good husk coverage.  CHIS740:S1411a-783-2-B-B was highly susceptible to heat stress with 65% plants showed leaf firing. CUBA164:S2012-444-1-B-B, FS8B(T):N11a-110-1-B-B, DKXL370:N11a20-199-2-B-B-B, DKXL370:N11a20-234-2-B-B-B, and UR11003:S0302-937-1-B-B were better than the other 11 GEM releases for most of the stress traits measured.   The best line was CUBA164:S2012-444-1-B-B, it had no leaf firing, low CEW damage, low grain mold, low percent of barren plants, good drought and stay green rating.

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TSG Accomplishments and Highlights:

• The TSG and lobby group was successful in their lobby efforts to Congress which resulted in an appropriation of $201,302 additional funding for GEM.  Their efforts were very appreciated and enabled GEM to expand research capabilities for breeding, testing, and support of Public cooperators.

• In June 2004, the TSG organized a successful interactive meeting in Raleigh, NC involving 3 USDA-ARS scientists from the genomics area.  This was an excellent opportunity to share ideas and explore new areas of research having mutual interest.  Genomic technologies (if feasible) will require new GEM Cooperators /and or partnering to enhance success of identifying allelic diversity for key target traits.  This should include more access to germplasm, winter nursery sites, and in kind support.

• The TSG successfully developed a web-based GEM survey resulting in more than 80 responses from GEM collaborators.  The results of the survey will be presented in Chicago and submitted for publication.

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PERSONNEL UPDATE:

Ames:  USDA-ARS Plant Introduction Unit

            Dr. Mike Blanco, GEM Coordinator and Geneticist

            Mack Shen, IT Specialist

            Sue Duvick, Quality Traits Lab Manager

            Andrew Smelser, GEM Technician

            Dr. Candice Gardner, Research Leader

Our former GEM Technician, Brian Alt, left GEM for a position in the private sector in May. We thank Brian for his excellent service to the GEM Project and wish him success. Andrew Smelser joined GEM this fall as a term employment federal technician.  Hiring is underway for a permanent technician to replace Mr. Alt.  

We welcome back Sue Duvick after her medical leave from a serious injury.

Raleigh:  USDA-ARS

           Joe Hudyncia, Southeastern GEM Coordinator (Agricultural Research Technician).

            Dr. Jim Holland, Maize Research Geneticist, GEM Collaborator.

            Peter Balint-Kurti, Research Geneticist, GEM Collaborator

            Vickie Brewster, Research Support Scientist.

            Dr. David Marshall, Research Leader and Fund holder.

            NC State University

            Dr. Major Goodman, Professor, GEM Collaborator

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IN KIND SUPPORT MIDWEST GEM PROJECT IN 2004:

The focus was to generate more S1 families and work a minimum of 30 new breeding cross families per year through the combined efforts of GEM and private cooperators. We worked more than 30 families per year in 2003 and 2004.  In addition, our focus in 2004 summer and 2004-5 winter was to create more new breeding crosses by requesting private cooperators to cross their proprietary lines to the best GEM accessions and/or 50% exotics to make 25% breeding crosses.  Support for this effort was very impressive.  For 2004 summer and 2004-5 winter more than 38 new breeding crosses have been, or are presently being made.  Thanks to GEM private Cooperators for their continued efforts making new breeding crosses and other in kind nursery and/or yield trial efforts. 

Table 3. Private In-Kind Nursery Support – Summer 2004