Germplasm Enhancement of Maize

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Accomplishments
Cooperator's Meeting
TAC Meeting
Personnel Changes
Publicity
Field Day
GEM SCA
Breeding Program
NC Breeding
Nursery
Winter Nursery
BC Advance
Yield Trials
YT Summary
Lab Reports
DSC Measurement

GEM - 1998 Annual Report

1998 Accomplishments

  • Over 11,000 yield plots were conducted at or coordinated from Ames. 
  • Thirty-two breeding crosses were selected for advancement by Ames. 
  • Over 1500 topcrossed lines will be available for Corn Belt yield testing in 1999. 
  • 200 topcrossed S2 lines from GEM breeding crosses beat the average of commercial check hybrids in trials analyzed to date at Ames. 
  • GEM's value-added research capacity expanded with the addition of a Waters High Performance Liquid Chromatography (HPLC) system with an UV-VIS detector to measure amino acid and anti-oxidant content of GEM lines. 
  • In Raleigh, about 30 of the approximately 200 families tested in second-year trials are competitive with commercial check hybrids. 
  • GEM’s capacity for field research in Ames expanded with the acquisition of a Gleaner K combine with three-row corn head (thanks to Les Lewis for funds to install air conditioning, Pioneer Hybrids International for the combine and hauling to Indiana, and Dekalb Genetics for hauling from Indiana,) converted to a plot combine. 
  • A field day was held on September 23 at the CAD Uthe farm in Ames. 
  • GEM gained international status with Embrapa, Brazil becoming a cooperator. This brings the total to 23 private, 43 public, and one international cooperators. 
  • A total of 12 public cooperator projects were partially supported financially by GEM. 
  • Identified three lines with very high % retrogradation (%R), CUBA164: S1511b-38-1-3, CUBA164:S1511b-34-1-3 and CUBA164:S2008a-31-1-3 with 83.8%, 86.7%, and 83.9% respectively. High %R starch may be a “resistive starch” meaning that it readily retrogrades or recrystallizes. Resistive starch potential uses include a new source of dietary fiber or as a dry lubricant or dusting powder in industrial applications e.g. as a lubricant between the multiple layers of plastic as is used in plastic lamination (hot dog packages) and in plastic gloves. 
  • Identified a line, AR16035: S02-500-24, with low protein, 5.1%, a line, SCROGP:N1310-213-22, with high protein, 15.4%, and a line, AR16035:S02-214-6, with high starch content, 73.6%. 

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Cooperator’s Meeting in Chicago, IL (December 10, 1997)

Twenty-seven cooperators attended the meeting. Annual reports were presented by Linda Pollak (Coordinator), Major Goodman (North Carolina Cooperator), Susan Duvick (Lab Manager), and Tim Johnson (Data Manager) who discussed progress on the 1997 Yield Testing Data Summary. Preliminary reports were given by the public cooperators: Craig Abel, Jim Coors, Neil Widstrom, Richard Pratt, and Gary Munkvold. Dave Harper discussed restructuring of breeding protocol. Dana Eaton was elected to replace Randy Holley on the TSG, and Ron Walejko was elected to replace Kevin Montgomery. A mid-meeting coffee break gave cooperators an opportunity to network.
 

Technical Advisory Committee (TAC) Meetings

December 9, 1997, Chicago, IL:

  • Ron Phillips, an invited guest, discussed the Plant Genome Research Program, which recently received funding of $40million through National Science Foundation. In particular, he discussed GEM’s relationship to this genome work as a shared structural resource dealing with genetic resources. 
  • Discussion was conducted about formation of new breeding crosses with new exotic materials. 
  • Funding decisions for public cooperators were approved. 
  • Randy Holley suggested some effort be made to developing lines for the genome work without regard to yield potential. 
  • A suggestion to make breeding crosses with zone 5 or 6 inbreds to target lines for zone 6 was made. 
February 17, 1998, Ames, IA: This meeting was cancelled because several members were unable to attend.

June 2, 1998, Ames, IA:

  • Ron Cantrell, Head of ISU’s Agronomy Department, and David Topel, Dean of ISU’s College of Agriculture, were invited guests. Dr. Cantrell suggested being risky, less afraid of failure. Dean Topel suggested that public cooperators seek matching grants, and that GEM involve commodity groups and others able to lobby at high levels. 
  • Protocol for retesting lines for potential release (use two testers), and for collection of data on these lines was discussed. Agronomic data should be collected on S2’s, while disease/insect testing should be on S3’s. Grain quality traits will be collected on second year topcrosses to correlate back to the S3 line in the test. Use 3 or more locations, 4-5 ears at each location selfed and bulked for analysis. 
  • GEM lines release nomenclature will be GEMN#### and GEMS### for nSS and SS lines, respectively. Release notices will include primary developer, institution, in kind support cooperators involved not mentioned but their companies will be mentioned, TSG and USDA indicated as cooperators with primary developer. 
  • Seed orders for S2 lines will not be filled until increased to S3’s. 
  • Common checks will be reviewed yearly by Pioneer and Holden’s principal contacts, possible adding grain quality, Bt, and other types of checks. 
  • Linda will cooperate with Ed Coe on a genomics grant proposal to NSF using GEM lines. Companies were not concerned with sequencing of breeding crosses or lines using SSR’s. 
August 19, Raleigh, NC:
  • A new department head will be hired at ISU, after which USDA will hold an external review of GEM. The review was requested by Les Lewis (Research Leader) and Rick Dunkle (Area Director). Names of potential external reviewers were discussed. Hiep Pham, David Harper, and Marty Carson will help Linda organize for the review.   
  • Cerestar, a starch processing company, is a new private cooperator. They will do amylose content, starch granule particle size distribution analysis, and wet milling characteristics as their in kind support (as compared to nursery rows, yield plots, and disease observation plots for seed companies), and expertise and commercialization for value-added traits as their proprietary contribution (as compared to germplasm for seed companies). 
  • Marty Carson discussed problems in the southern area such as lack of cooperators, labor resource limitations, early planting dates compared to the central area, and late date for availability of data. 
  • Discussion was made of public cooperator visits made by TSG members, and the questioning of ARS concerning use of GEM funds because of poor data submission track record of some public cooperators. In the future, need data (or response of some kind) by deadline outlined in signed specific cooperative agreements or new funding will not be extended. 
  • Wilfredo will leave as member and chair as Pioneer will no longer fund his travel (contract ending at the end of the year) unless other funding is secured. TSG will investigate continuing funding for his chair position for 3 years. Jim Coors and Don White due to rotate off, Dirk Benson and Dave Harper would remain for continuity of lobbying. Giving public members $1000 per year for travel honorarium to meetings not held in conjunction with other meetings was proposed; require 2 meetings/year minimum for public cooperator members. 
  • The future of GEM in relation to database issues was discussed. GEM needs to establish a real, accessible database. Both GRIN and Maize genome database wants links with our data. The TSG will lobby ARS for funding, and Hiep Pham will help Linda with plans/ideas. 
  • Ideas were put forth to sell our materials. A subcommittee of Data Eaton (chair), Dirk Benson, Kevin Montgomery, and Doug Tiffany was formed to promote, package, and sell our germplasm most effectively. 
  • The Genome proposal involving GEM was thrown out by NSF. 

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Personnel Changes

Chris Halweg successfully completed his USDA internship in the GEM laboratory. Chris accepted a graduate research assistant position at North Carolina State University to study genetics. Tyler Lameroux is the new USDA intern. He is completing his second year of undergraduate work at Ellsworth Community College and will transfer to Iowa State University in summer 1999 to study agronomy.

Publicity

  • GEM description in ISU’s College of Agriculture 1997 Annual Report.

  • Article in The Messenger/Farm News, Fort Dodge IA, January 30.

  • Article in February’s Seed & Crops Digest.

  • Article in Integrated Crop Management-Crops Research Edition, Winter 1998.

  • Article in Iowa Farmer Today, February 14.

  • Presentation of Results of 1996 GEM Laboratory Analyses at NCR-167 by Susan Duvick, Ames IA, February 16.

  • Invited presentation “A program for developing and characterizing exotic corn crosses with value-added starch and oil” by Pam White at 10th Annual Food Focus, Minneapolis

  • Poster display at ISU Agronomy Day on September 10.

  • Invited presentation “Productivity and quality in cereal improvement and production” at Brazilian Congress of Corn and Sorghum, Recife, Brazil, September 9.

  • Invited presentation “Public-private sector collaboration in maize germplasm enhancement in the USA” at Asian Seed ’98, Manila Philippines, September 24.

  • Article “Taking corn into future” in Sunday’s Des Moines Register, October 4.

  • Poster “Corn elite germplasm enhancement:results of the use of South American corn resources” by A.T. Kraja, J.W. Dudley, D.G. White, at ASA Meetings October 22, Baltimore.

  • Poster “Yield potential of GEM project breeding crosses” by L. Pollak, W. Salhuana, and T. Johnson, at ASA Meetings, October 22, Baltimore.

  • Poster “Yield potential of GEM project breeding lines” by T. Johnson, L. Pollak, and W. Salhuana, at ASA Meetings, October 22, Baltimore.

  • December News Release by ISU “Using the exotic to expand value-added agriculture at home”

  • Publication of “Genetic variability in exotic x adapted maize (Zea mays L.) germplasm for resistance to maize weevil” by R. Li, M.S. Kang, O.J. Moreno, L.M. Pollak in Plant Genetics Resources Newsletter 114:22-25.

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1998 Field Day 

September 23, 1997, Ames, IA: The field day was held at the Committee for Agricultural Development’s Uthe Farm. The Central Iowa Field day was held at the same location on September 23-24.Having our field day held in association with the Central Iowa Field Day meant that attendance by commercial people increased significantly over the two days. On September 23 official greetings from USDA-ARS came from Corn Insects and Crop Genetics Research Leader Leslie Lewis. Official greetings from Iowa State University came from Dean David Topel. Official greetings from GEM came from TSG chair Wilfredo Salhuana and member Dave Harper. Susan Duvick gave a poster. Featured GEM breeding materials were value added trait selections, new breeding crosses, and breeding crosses recommended by public cooperators, as well as a demonstration of breeding progress in exotic and Corn Belt materials.

 

Public Cooperators Supported in 1998

Name
$ Funded

Research Supported 

John Dudley
6000
Evaluation of tropical accessions as sources of genes to improve a Corn Belt hybrid for grain yield and disease resistance
Gary Munkvold
5000
Fusarium ear rot resistance screening of GEM germplasm
Jerry Sell
4041
Evaluation of two varieties of experimental corns as feed ingredients for broiler chickens
Paul Scott
3000
Evaluation for zein content
Mark Campbell
2143
Influence of exotic background on amylose extender gene
Margaret Smith
5000
Anthracnose stalk rot resistance from exotic maize germplasm
Richard Pratt
5000
Introgression of grain quality traits from GEM germplasm to Corn Belt maize
Jim Hawk (breeding)
9000
Inbred line development in DKXL212:N11a and evaluation of testcrosses in irrigated and dryland conditions
Robert Lambert
5000
Development of GEM corn lines with multiple disease resistance, starch content, and grain yield
Dean Barry, Bruce Hibbard, Larry Darrah
6500
Evaluation and development of GEM materials for European corn borer, western corn rootworm, rind penetrometer, and vertical root pulling resistance
Neil Widstrom 
4000
Southern yield tests
Dennis West 
5000
Southern yield tests and line development

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Ames, IA - Breeding Program

 
98 Iowa Nursery: 64 lines increased for possible release, 30 lines for further evaluation, 26 backcross regenerations, 32 value added lines for intensive starch evaluations, 1326 rows for developing value-added lines, and 4087 rows for making S3’s. 
98 Iowa Isolations:  Production of Mo17, B73 and (Mo17 x B73) for lab checks. 
98 Puerto Rico Nursery: 389 rows for developing GEM lines for value-added traits. 
98 Puerto Rico Isolation: 536 rows of SS females to topcross to nSS tester. 

Raleigh, NC - Breeding Program

Production and Evaluation of GEM Accessions Suitable for Enhancement

The project consists of four types of activities:

  • Generation of 50%-tropical, 50% temperate families in the nursery, starting with the various breeding crosses. 
  • Production of topcross seed for yield trial experiments. 
  • Running yield trials, collecting and analyzing the yield trial data. 
  • Arranging cooperative tests with other public and private breeding organizations and providing the counted seed to these organizations. 
  • Analyzing the combined data sets from the yield trials run by us and other cooperators. 
  • Selecting breeding crosses and families to include in the next cycle of testing. 
Slightly over 1,000 plots (nominally 25 plants each) were used during the winter and summer season for selfing to produce families. This year we emphasized increases of families, which had performed well in first-year yield trials. An additional 2,000 observation plots of F1S2s were planted to select for general agronomic worth and for advancement into testcross yield trials. Of these, 115 F1S2s from Pasco14 ss01 are being testcrossed this winter for 1999 yield trials.

We utilized over 700 plots to make topcross seed, about half of which was made by hand pollinations and about half of which was done in isolated, detasselled fields. An additional set of 700 was done for us by hand pollination by Novartis, utilizing their Puerto Rico facilities.

We planted GEM yield trials at four locations in North Carolina, one of which (Sandhills, with about 3,000 plots), was lost to extreme heat and drought stress. A few trials (almost 300 plots) were lost to a hurricane at Lewiston, N.C. Basically, good data were acquired for all second year trials (about 800 plots) and data was lost for first year trials.

We chose to place emphasis on increasing, testing, and generating second-tester topcrosses of the more elite materials rather than generating more families or topcrosses of untested materials (we already have a large backlog of both topcrosses and of untested families). Several sources appear to be the most promising of the 16 that have had two years of trials. The best are DK888 S11, PE1 N16, and DK380 S11.

About 7,800 GEM yield trial plots were planted by 12 cooperators in 7 states, about 1/3 of which were second year trials. To date, almost 1,800 of these were lost due to either drought or flooding (80% of these were first-year trials). Reports have been received from 8 of the cooperators thus far; three additional ones have said that their data will be available shortly.

Final data for 1997 were not complete until mid-January, 1998.They were combined with data received earlier and summarized immediately. Approximately 200 of 750 GEM entries were selected for second-year yield trials. These entries performed at the level of the median of the check entries, a surprisingly favorable result for 50%-tropical families, about 1/3 of which represented germplasm-accession sources.

We have slightly more than ½ of the data for 1998 in from cooperators, but have enough in to summarize the second year trials. It appears thus far that about 30 of the approximately 200 families tested in second-year trials are competitive with commercial check hybrids. Disease data on 50% breeding crosses is still being analyzed. Big White ss03 continues to looking promising for both Fusarium and Aspergillus ear rot resistance.F1S2s from this cross were advanced to F1S3s this summer for further selection and evaluation.

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1998 Cooperative Nursery Work

Private In-kind Nursery Support - Summer, 1998

 

Company Nursery RowsPledged Rows Will Do  Populations Populations From 
Bo-Jac  100 Making S1’s AR16035:S19   
Cargill 200  S1 to S2 DKXL370:N11a20  Crow’s
DeKalb  500  S1 to S2 

Making S1’s

CHIS740:S1411a

AR16026:S1704

DeKalb
FFR Coop 50 Making S1’s  AR16021:S0908b  
Global Agro 200 S1 to S2  AR16035:S19  Global Agro
Golden Harvest  500 S1 to S2 AR16026:S17  
Great Lakes 250 S1 to S2 DKXL370:N11a20  Crow’s
Growmark 150 Making S1’s  UR01089:S24   
Hoegemeyer 350 Making S1’s 

Topcrosses for 99’ 

FS8B(S):S0316 

DKB844:S1601

 
Holdens 500  Making S1’s 

Making S1’s 

Making S1’s 

AR17056:N2025 

FS8B(S):S0301 

UR11003:S0302 

 
Garst 500 Making S1’s 

Making S1’s 

Making S1’s 

CASH:N1410 

FS8B(T):N1802 

AR01150:S0125

 
Gowan Seeds  100 Making BC’s 4 Temperate 25% Exotics   
Jung Farms 400 Making S1’s UR13085:N0215  
Limagrain 500 Making S1’s 

Making S1’s 

Making S1’s 

ANTIG01:S0225 

AR16035:S02 

UR01089:N225 

 
NC+  200 Making S1’s UR11003:S0302   
Novartis 500   From Major   
PAU Seeds  250 Making S1’s 

Making S1’s 

DK212T:S0610 

UR13088:S0607 

 
Pioneer  800 Making S1’s 

Making S1’s 

Making S1’s 

UR01089:S0225 

GUAT209:N1925 

AR03056:N1625 

 
Wilson 300 Making S1’s 

Making S1’s

DK212T:S0610 

AR13026:S15 

 
Wyffels 250 Making S1’s BR52051:N04  

 

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Private In-kind Nursery Support - Winter 1998-99

Company
Nursery Rows Pledged
Comments
Bo-Jac
50
Making S1’s
Cargill
100
Topcrossing 100 S2's ofDKXL370:N11a20 from Cargill
DeKalb
150
Topcrossing 150 S2's ofCHIS740:S1411am from DeKalb
FFR Coop
20
Making S1’s
Golden Harvest
200
Making breeding crosses Topcrossing 112 S2's ofAR16026:S17
Great Lakes
150
Topcrossing 150 S2's of DKXL370:N11a20 from Great Lakes
Growmark
100
Making breeding crosses
Hoegemeyer
0
No Winter Support
Holdens
200
Topcrossing 2 testers to lines for release for final testing.
Garst
100
Making breeding crosses.
Limagrain
100
Making breeding crosses.
NC+
100
Making breeding crosses.
Novartis
100
Materials from Major Goodman
Pioneer
300
Making breeding crosses.
Wyffels
100
Making breeding crosses.
Crow's
0
No Winter Support
Pau
100
Making breeding crosses
Wilson 
100
Making breeding crosses

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Breeding Crosses Advanced - Summer 1998 and Winter 1998-1999

Breeding Cross
Cooperator
CLG1607:N11
Linda Pollak
CML325:S11
Linda Pollak
CLG1501:N15
Linda Pollak
CML287:S15
Linda Pollak
CLG1703:N15
Linda Pollak
CML323:N15
Linda Pollak
CML329:N15
Linda Pollak
AR16035:S19
Bo-Jac
CH05015:N1204
Bo-Jac
AR16026:S1704
DeKalb
AR16021:S0908b
FFR
CASH:N1410
Garst
FS8B(T):N1802
Garst
AR01150:S0125
Garst
UR01089:S24
Growmark
FS8B(S):S0316
Hoegemeyer
AR17056:N2025
Holdens
FS8B(S):S0301
Holdens
UR11003:S0316
Holdens
UR13085:N0215
Jung Seed Genetics
ANTIG01:S0225
Limagrain
AR16035:S02
Limagrain
UR01089:N2225
Limagrain
UR11003:S0302
NC+
DK212T:S0620
PAU
UR13088:S0607
PAU
UR01089:S0525
Pioneer
GUAT209:N1925
Pioneer
AR03056:N1625
Pioneer
DK212T:S0610
Wilson
AR13026:S15
Wilson
BR52051:N04
Wyffels

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1998 Cooperative Yield Testing

In all, there were 22 experiments ranging from six to eight replications, with a total of 132.  

Plots with Private Cooperators
7795
Plots with Public Cooperators
416
Plots in Ames
4347
TOTAL MIDWEST YIELD PLOTS
12558
Plots in disease observations
1443

1998 GEM Yield Test Entries

50% tropical breeding crosses
508
25% tropical breeding crosses
272
50% temperate breeding crosses
86
25% temperate breeding crosses
508
Tropical backcrosses
69
TOTAL ENTRIES
1443

 

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Private Cooperator Yield Trials

Experiment

Cooperator Making Topcross

%Exotic

Tester

Zone

Number of Entries

Number of Replications

98121

Holdens

50%

nSS

tropical

125

7

98122

Holdens

50%

nSS

tropical

95

9

98123

Holdens

50%

SS

tropical

208

7

98124

Limagrain

50%

SS

tropical

61

7

98131

Holdens

25%

nSS

tropical

73

8

98132

Holdens

25%

SS

tropical

58

7

98134

NC+

25%

nSS

tropical

70

7

98135

Pioneer

25%

nSS

tropical

126

7

98136

Wyffels

25%

SS

tropical

54

7

98137

Wyffels

25%

SS

tropical

38

7

98221

Holdens

25%

nSS

temperate

86

8

98222

DeKalb

25%

SS

temperate

166

7

98231

Holdens

25%

SS

temperate

38

7

98232

Cargill

25%

SS

temperate

110

7

98234

Growmark

25%

SS

temperate

55

7

98235

Golden Harvest

Both

nSS

temperate

280

7

98236

Garst

Both

nSS

temperate

50

7

98237

Garst

Both

nSS

temperate

50

7

98238

Garst

Both

nSS

temperate

50

7

98239

Garst

25%

nSS

temperate

40

7

98601

Pioneer

Both

SS

both

45

7

98602

Holdens

Both

nSS

both

25

7

 

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Summary of Yield Trial 1998

 

Experiment

Cooperators Making Topcross

Tester Type

Number of Entries

Number of Replications

22

9

10-SS & 12-nSS

1903

158

Data Summary Book

The GEM Project Data Summary provides a complete overview of GEM results throughout the year. The 1998 GEM Data Summary book will contain yield data from all trials held in the United States both public and private. Disease ratings of the material in yield trial by private cooperators are included in the data summary. Public cooperator summaries and data will be also be featured in the GEM. The book will be available at the NCR-167 meetings in February. The book will be available as a Compact Disk.

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Laboratory Report

  • The S1 lines from the 50% breeding Cross CUBA117:S15 from 1997 and Corn Belt checks were evaluated for fatty acid composition (GC analysis). 
  • Identified a S1 line from CUBA117:S15 had a Palmitic acid value of 16%. 
  • Identified a S1 line from CUBA117:S15 had a Stearic acid value of 3.8%. 
  • Identified a S1 line from CUBA117:S15 had a Total Saturated fatty acid value of 18.2%. 
  • Corn lines high in Palmitic and Stearic acid content are useful in a breeding program for corn with elevated saturated fatty acid oil. 
  • Corn oil higher in saturated fatty acid content has reduced peroxide formation, which results in increased oxidative stability and reduced rancidity (longer shelf life). 
  • The Composition (NIR) analysis is completed for grain quality traits of individual S2 ears from the high protein/oil selections in AR16035:S02 and SCROGP:N1310 materials. 
  • Identified a line, SCROGP:N1310-509-19, with low protein, 5.7%. 
  • Identified a line, AR16035:S02-500-24, with low protein, 5.1%. 
  • Identified a line, AR16035:S02-644-6, with high protein, 15.0%. 
  • Identified a line, SCROGP:N1310-213-22, with high protein, 15.4%. 
  • Identified a line, AR16035:S02-275-24, with elevated oil content, 5.7%. 
  • Identified a line, SCROGP:N1310--378-11, with elevated oil content, 5.3%. 
  • Identified a line, AR16035:S02-214-6, with high starch content, 73.6%. 
  • Identified a line, SCROGP:N1310-95-12, with high starch content, 72.8%. 
  • All Gem Fast Track S3 lines from winter 1996 nursery are processed for single kernel starch extraction. 
  • The Differential Scanning Calorimeter (DSC) analyses for starch thermal properties of the Gem Fast Track S3 lines from winter 1996 nursery are nearly completed. 
  • Identified a line, CUBA164:S2008a-9-1-2, with low onset of gelatinization (ToG), 62.9°C. 
  • Identified a line, DK212T:S0610-25-1-1, with a narrow range of gelatinization (RnG), 4.4°C. 
  • Identified a line, CUBA164:S2008a-9-1-2, with a wide range of gelatinization (RnG), 14.4°C. 
  • Identified a line, CHIS775:S1911b-16-1-1, with low energy of gelatinization(DHG), 2.3 cal/g. 
  • Identified a line, DK212T:S0610-8-1-3, with high energy of gelatinization (DHG), 4.1 cal/g. 
  • Identified a line, CHIS775:S1911b-37-1-1, with low energy of regelatinazation (DHR).1.1 cal/g. 
  • Identified three lines with very high % retrogradation (%R), CUBA164:S1511b-38-1-3, CUBA164:S1511b-34-1-3 and CUBA164:S2008a-31-1-3 with 83.8%, 86.7%, and 83.9% respectively. 
  • High %R starch may be a “resistive starch” meaning that it readily retrogrades or recrystallizes. 
  • Resistive starch potential uses include a new source of dietary fiber or as a dry lubricant or dusting powder in industrial applications e.g. as a lubricant between the multiple layers of plastic as is used in plastic lamination (hot dog packages) and in plastic gloves. 

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Oil Quality Data

Ten kernels from each ear were individually crushed, extracted, converted to fatty acid methyl esters (FAMES) and analyzed with gas chromatography to determine the fatty acid compositions of the five major fatty acids in corn oil: C16:0, Palmitic acid; C18:0, Stearic acid; C18:1, Oleic acid; C18:2, Linoleic acid; and C18:3, Linolenic acid.

 

Table 1. Corn Belt Checks: Fatty Acid Compositions (%). 

Entry

Palmitic

Stearic

Oleic 1

Linoleic1

Linolenic

Tot Sats

Pioneer 3394

10.9

2.0

27.9

58.2

1.1

12.9

Pioneer 3489

10.0

2.1

23.4

63.7

0.7

12.1

Pioneer 3163

12.1

2.2

22.4

62.4

0.9

14.3

Pioneer 3525

9.4

1.4

24.6

63.4

1.2

10.8

Mo17

10.1

2.0

24.2

63.0

0.8

12.1

1Means of 10 kernels per ear.

 

Table 2. Fatty Acid Composition of CUBA117: S15 S1 lines with unusual values (%), 

Entry

Palmitic 1

Stearic

Oleic1

Linoleic1

Linolenic 1

Tot Sats

972066

16.0

1.5

32.8

48.6

1.0

17.6

972024

12.5

3.8

30.0

52.5

1.2

16.3

972171

15.5

2.7

31.9

48.9

1.0

18.2

1Means of 10 kernels per ear.

Whole Grain Composition Data

Table 3. NIR Whole grain composition of Corn Belt checks, individual S2 ears from the high protein/oil selections in AR16035:S02 and SCROGP:N1310 materials. 

Sample

Protein (%)*

Oil (%)*

Starch (%)*

B73

10.9

3.2

72.2

Mo17

11.9

3.4

70.2

Pioneer 3394

11.0

3.3

70.7

Pioneer 3489

8.6

4.6

70.3

AR16035:S02-500-24

5.1

1.5

71.8

AR16035:S02-644-6

15.0

4.2

66.7

AR16035:S02-275-24

11.9

5.7

66.0

AR16035:S02-214-6

10.2

3.7

73.6

SCROGP:N1310-509-19

5.7

2.8

70.2

SCROGP:N1310-213-22

15.4

3.3

65.7

SCROGP:N1310--378-11

12.4

5.3

66.1

SCROGP:N1310-95-12

9.5

3.3

72.8

*Dry Matter Basis

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Starch Quality Data: Thermal Analysis

Table 4. Target Values for Starch Thermal Properties*

 

TpG ( peak onset of gelatinization)
Below 60°C
DHG (enthalpy of gelatinization)
Less than2.5cal/g or more than 4cal/g
RnG (range of gelatinization)
Less than 5°C or greater than 15°C
PHI (peak height index)
Above 1.2
DHR (enthalpy of retrogradation)
Less than 1cal/g
%R (percent retrogradation)
Less than 20% or greater than 80%
*See Target sheet for additional explanation

 

Table 5. DSC Values for Corn Belt Checks 

Entry ToG (°C) ToR (°C) TpG (°C) TpR (°C) RnG (°C) RnR (°C) DHG (cal/g) DHR (cal/g) PHI %R
Sigma 65.1 41.3 69.7 50.2 9.1 18.0 2.9 1.1 0.7 38.8
Mo17 70.4 40.9 72.4 50.7 5.7 19.5 2.9 1.3 1.1 40.0
Pioneer 3394 64.1 41.7 69.7 50.6 11.1 18.1 2.7 1.2 0.5 48.2
Pioneer 3489 64.5 40.8 69.9 51.2 10.9 20.9 3.0 1.5 0.5 51.8

 

Table 6. Gem Fast Track S3 lines from winter 1996 nursery Lines with Unusual DSC Values 

Entry

ToG (°C)

ToR (°C)

TpG (°C)

TpR (°C)

RnG (°C)

RnR (°C)

DHG (cal/g)

DHR (cal/g)

PHI

%R 

CUBA164:S2008a-9-1-2

62.9

38.3

70.1

50.0

14.4

23.4

2.9

1.9

0.4

66.2

DK212T:S0610-25-1-1

69.0

37.6

71.1

49.9

4.2

24.7

3.5

2.0

1.7

55.8

CUBA164:S2008a-9-1-2

62.9

38.3

70.1

50.0

14.4

23.4

2.9

1.9

0.4

66.2

CHIS775:S1911b-16-1-1

65.4

42.3

70.7

50.5

10.5

16.5

2.3

1.2

0.4

53.8

DK212T:S0610-8-1-3

66.9

36.4

70.7

49.1

7.5

25.4

4.1

1.9

1.1

46.87

CHIS775:S1911b-37-1-1

66.1

41.8

70.8

52.9

9.3

22.2

3.0

1.1

0.6

38.70

DK212T:S0610-25-1-1

69.0

37.6

71.1

49.9

4.2

24.7

3.5

2.0

1.7

55.8

CUBA164:S1511b-38-1-3

65.9

34.2

70.5

48.4

9.3

28.3

2.9

2.4

0.6

83.8

CUBA164:S1511b-34-1-3

65.6

33.3

70.7

48.4

10.1

30.2

3.2

2.7

0.6

86.7

CUBA164:S2008a-31-1-3

65.0

37.9

70.0

50.5

10.0

25.3

3.1

2.6

0.6

83.9

 

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Measurement of Starch Quality with Differential Scanning Calorimetery

 

Starch represents nearly 70% of the dry weight of the mature corn kernel and is the most economically important component. Therefore, it is essential to determine the endosperm variation and starch quality of the GEM materials. The process has two steps. The first step is the extraction of the starch from the endosperm using a modified mini wet mill procedure developed in the GEM laboratory. The second step evaluates the starch qualities and structures by measuring the starch gelling properties with the differential scanning calorimeter (DSC). The DSC allows direct measurement of the energy required to gelatinize starch. The gelatinized samples are held for a week in a refrigerator and rescanned to determine the amount of retrogradation or recrystallization and hence the stability of the starch gel.

Several studies have examined how thermal properties, as measured by DSC, relate to structural and functional characteristics of the starch. These thermal properties and their implications are listed in Table 1.
 

DSC Parameter
Desired Characteristic
Tp
(Peak Onset of gelatinization) 
Low value means less energy required in starch cooking process. Target <60°C 
DHG 
(Enthalpy of gelatinization) 
Low value means less energy required in starch cooking process. Target <2.5 cal/g 
High value means extensive thickening power. 
Target >4.0g/cal 
Rn
(Range of gelatinization) 
Low value means starch granules are likely from a homogeneous population. Starch cooking can occur quickly within a brief range. 
Target <5°C. 
High value means starch granules are likely from a heterogeneous population. Starch cooking occurs over a wide temperature range. 
Target >15°C. 
PHI 
(Peak height index) 
(enthalpy/1/2 range) 
 High value means the thermogram has a tall narrow peak, which suggests high thickening power within a narrow temperature range. 
Target >1.2 
DHR 
(Enthalpy of retrogradation) 
Low value means the starch is not subject to aligning and recrystallizing. Starch is likely stable in frozen and refrigerated products. 
Target <1cal/g 
%R 
(Percentage of retrogradation) 
Low value gives similar meaning as previous parameter. More information about the relation to the original enthalpy is obtained. 
Target <20% 
High value may indicate presence of resistant starch. 
Target >80% 
Shape of the thermogram 
   
Double or triple peaks suggest two or more populations of starch granules. Starch cooking occurs over a wide temperature and may have multiple functions. 
Target: detection 

 

 

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