Progress 10/01/10 to 09/30/11
Outputs
Progress Report Objectives (from AD-416) The objective of this cooperative research project is to enhance the development of mycotoxin-resistant corn hybrids by identifying new resistant genes from world collections and incorporating them into existing breeding programs. Approach (from AD-416) Three major steps are outlined to improve resistance of commercial hybrids to aflatoxin biosynthesis. The first is large scale screening of corn germplasm (accessions) to identify new resistance. The second is to stabilize newfound resistance into improved populations. The third is to transfer resistance into commercial inbreds. Step one: Screen Corn Germplasm for Improved Resistance. Our screening procedure requires two seasons. In season one corn accessions are hybridized with B73 to produce F1 seed. Mr. Mark Millard, Maize Curator at the North American Plant Introduction Center in Ames, Iowa, will share responsibility to select accessions for screening and provide seed. Initial priority will be given to accessions originating from hot and dry climates where active or passive selection for resistance might have occurred. Accessions will be hybridized B73 to produce F1 seed in summer nurseries at Alexandria, Louisiana. B73 has been perhaps the most widely recognized corn inbred and represents one side of the most common heterozygous hybrid combination. Accessions hybridized with B73 produce F1 seed with improved vigor and ear size. Resistance in F1 seed also provides a better indicator of useful resistance than in the original accession. In season two, F1 ears are inoculated with Aspergillus flavus and screened for aflatoxin and fumonisin contamination. Screening nurseries are conducted in conventional 38-inch row spacings on a Norwood silt loam soil at the Dean Lee Research Station in central Louisiana by Dr. Steven Moore, LSU Ag Center corn breeder. A randomized complete block design is used with two replications. Each replication will include resistant checks of B73:Mp313e and B73:Tex6. The experimental unit is ten ears from a single row. Ears will be inoculated with A. flavus spores after anthesis using a hand-held pin bar apparatus dipped in a container containing spores in liquid suspension (about or equal to 90 million spores/ml). Ears will be harvested after physiological maturity, dried, ground to a fine meal and sent to the USDA-ARS facility at Stoneville, Mississippi, for aflatoxin and fumonisin analyses by Dr. Hamed Abbas, USDA Research Pathologist. Dr. Abbas will also maintain inoculum and provide spore suspensions at the time of anthesis. Resistance will be assessed by Dr. Moore. To date, 1600 lines from the North American Plant Intoduction Center have been planted in nurseries at Alexandria, LA, although many have not been successfully pollinated and screened. Step two: Develop Breeding Populations - Seed from accessions showing the lowest aflatoxin will be screened again to confirm resistance. Selected accessions crossed to B73 will be selfed to the F4 generation. Resistant and non-resistant populations will be identified and planned for use in commercial marker-assisted programs where resistance can be transferred into elite inbreds. Eleven lines with potentially improved resistance are now being advanced (Nigerian Composite B. Manio-PI490411, Haiti 33- PI483902, Saint Croix1-PI484036, TZI18-PI506253, Tx81, Tx807 and CML43- PI595535). Step three: Transfer Improved Resistance into Commerical Inbreds. Progress concluded with the 2010 Annual Report, but was not terminated because of financial management reasons. See 2010 Annual Report for last reported progress.
Impacts
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Publications
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Progress 10/01/09 to 09/30/10
Outputs
Progress Report Objectives (from AD-416) The objective of this cooperative research project is to enhance the development of mycotoxin-resistant corn hybrids by identifying new resistant genes from world collections and incorporating them into existing breeding programs. Approach (from AD-416) Three major steps are outlined to improve resistance of commercial hybrids to aflatoxin biosynthesis. The first is large scale screening of corn germplasm (accessions) to identify new resistance. The second is to stabilize newfound resistance into improved populations. The third is to transfer resistance into commercial inbreds. Step one: Screen Corn Germplasm for Improved Resistance. Our screening procedure requires two seasons. In season one corn accessions are hybridized with B73 to produce F1 seed. Mr. Mark Millard, Maize Curator at the North American Plant Introduction Center in Ames, Iowa, will share responsibility to select accessions for screening and provide seed. Initial priority will be given to accessions originating from hot and dry climates where active or passive selection for resistance might have occurred. Accessions will be hybridized B73 to produce F1 seed in summer nurseries at Alexandria, Louisiana. B73 has been perhaps the most widely recognized corn inbred and represents one side of the most common heterozygous hybrid combination. Accessions hybridized with B73 produce F1 seed with improved vigor and ear size. Resistance in F1 seed also provides a better indicator of useful resistance than in the original accession. In season two, F1 ears are inoculated with Aspergillus flavus and screened for aflatoxin and fumonisin contamination. Screening nurseries are conducted in conventional 38-inch row spacings on a Norwood silt loam soil at the Dean Lee Research Station in central Louisiana by Dr. Steven Moore, LSU Ag Center corn breeder. A randomized complete block design is used with two replications. Each replication will include resistant checks of B73:Mp313e and B73:Tex6. The experimental unit is ten ears from a single row. Ears will be inoculated with A. flavus spores after anthesis using a hand-held pin bar apparatus dipped in a container containing spores in liquid suspension (about or equal to 90 million spores/ml). Ears will be harvested after physiological maturity, dried, ground to a fine meal and sent to the USDA-ARS facility at Stoneville, Mississippi, for aflatoxin and fumonisin analyses by Dr. Hamed Abbas, USDA Research Pathologist. Dr. Abbas will also maintain inoculum and provide spore suspensions at the time of anthesis. Resistance will be assessed by Dr. Moore. To date, 1600 lines from the North American Plant Intoduction Center have been planted in nurseries at Alexandria, LA, although many have not been successfully pollinated and screened. Step two: Develop Breeding Populations - Seed from accessions showing the lowest aflatoxin will be screened again to confirm resistance. Selected accessions crossed to B73 will be selfed to the F4 generation. Resistant and non-resistant populations will be identified and planned for use in commercial marker-assisted programs where resistance can be transferred into elite inbreds. Eleven lines with potentially improved resistance are now being advanced (Nigerian Composite B. Manio-PI490411, Haiti 33- PI483902, Saint Croix1-PI484036, TZI18-PI506253, Tx81, Tx807 and CML43- PI595535). Step three: Transfer Improved Resistance into Commerical Inbreds. New genes are needed to develop corn hybrids with resistance to Aspergillus flavus and aflatoxin biosynthesis. From 1,900 lines, twelve lines have been selected and planted for trials at LSU in 2009. The ARS scientist will complete analysis for mycotoxins on sampled to be provided from these tests. However, as the LSU cooperator resigned there is no new progress from the collaborator to report. The ADODR monitored this project through frequent visits, telephone and e-mail communications before resignation of the cooperator.
Impacts
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Publications
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Progress 10/01/08 to 09/30/09
Outputs
Progress Report Objectives (from AD-416) The objective of this cooperative research project is to enhance the development of mycotoxin-resistant corn hybrids by identifying new resistant genes from world collections and incorporating them into existing breeding programs. Approach (from AD-416) Three major steps are outlined to improve resistance of commercial hybrids to aflatoxin biosynthesis. The first is large scale screening of corn germplasm (accessions) to identify new resistance. The second is to stabilize newfound resistance into improved populations. The third is to transfer resistance into commercial inbreds. Step one: Screen Corn Germplasm for Improved Resistance. Our screening procedure requires two seasons. In season one corn accessions are hybridized with B73 to produce F1 seed. Mr. Mark Millard, Maize Curator at the North American Plant Introduction Center in Ames, Iowa, will share responsibility to select accessions for screening and provide seed. Initial priority will be given to accessions originating from hot and dry climates where active or passive selection for resistance might have occurred. Accessions will be hybridized B73 to produce F1 seed in summer nurseries at Alexandria, Louisiana. B73 has been perhaps the most widely recognized corn inbred and represents one side of the most common heterozygous hybrid combination. Accessions hybridized with B73 produce F1 seed with improved vigor and ear size. Resistance in F1 seed also provides a better indicator of useful resistance than in the original accession. In season two, F1 ears are inoculated with Aspergillus flavus and screened for aflatoxin and fumonisin contamination. Screening nurseries are conducted in conventional 38-inch row spacings on a Norwood silt loam soil at the Dean Lee Research Station in central Louisiana by Dr. Steven Moore, LSU Ag Center corn breeder. A randomized complete block design is used with two replications. Each replication will include resistant checks of B73:Mp313e and B73:Tex6. The experimental unit is ten ears from a single row. Ears will be inoculated with A. flavus spores after anthesis using a hand-held pin bar apparatus dipped in a container containing spores in liquid suspension (about or equal to 90 million spores/ml). Ears will be harvested after physiological maturity, dried, ground to a fine meal and sent to the USDA-ARS facility at Stoneville, Mississippi, for aflatoxin and fumonisin analyses by Dr. Hamed Abbas, USDA Research Pathologist. Dr. Abbas will also maintain inoculum and provide spore suspensions at the time of anthesis. Resistance will be assessed by Dr. Moore. To date, 1600 lines from the North American Plant Intoduction Center have been planted in nurseries at Alexandria, LA, although many have not been successfully pollinated and screened. Step two: Develop Breeding Populations - Seed from accessions showing the lowest aflatoxin will be screened again to confirm resistance. Selected accessions crossed to B73 will be selfed to the F4 generation. Resistant and non-resistant populations will be identified and planned for use in commercial marker-assisted programs where resistance can be transferred into elite inbreds. Eleven lines with potentially improved resistance are now being advanced (Nigerian Composite B. Manio-PI490411, Haiti 33- PI483902, Saint Croix1-PI484036, TZI18-PI506253, Tx81, Tx807 and CML43- PI595535). Step three: Transfer Improved Resistance into Commerical Inbreds. Significant Activities that Support Special Target Populations New genes are needed to develop corn hybrids with resistance to Aspergillus flavus and aflatoxin biosynthesis. From the 1,900 lines twelve lines have been selected and planted for trials at LSU in 2009. The ARS scientist will complete analysis for mycotoxins on samples to be provided from these tests. However, as the cooperator resigned from LSU and there is no funding to cover analytical supplies it is requested that the project be terminated. ADODR monitored activities of this project through frequent visit, telephone and e-mail communications.
Impacts
(N/A)
Publications
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Progress 10/01/07 to 09/30/08
Outputs
Progress Report Objectives (from AD-416) The objective of this cooperative research project is to enhance the development of mycotoxin-resistant corn hybrids by identifying new resistant genes from world collections and incorporating them into existing breeding programs. Approach (from AD-416) Three major steps are outlined to improve resistance of commercial hybrids to aflatoxin biosynthesis. The first is large scale screening of corn germplasm (accessions) to identify new resistance. The second is to stabilize newfound resistance into improved populations. The third is to transfer resistance into commercial inbreds. Step one: Screen Corn Germplasm for Improved Resistance. Our screening procedure requires two seasons. In season one corn accessions are hybridized with B73 to produce F1 seed. Mr. Mark Millard, Maize Curator at the North American Plant Introduction Center in Ames, Iowa, will share responsibility to select accessions for screening and provide seed. Initial priority will be given to accessions originating from hot and dry climates where active or passive selection for resistance might have occurred. Accessions will be hybridized B73 to produce F1 seed in summer nurseries at Alexandria, Louisiana. B73 has been perhaps the most widely recognized corn inbred and represents one side of the most common heterozygous hybrid combination. Accessions hybridized with B73 produce F1 seed with improved vigor and ear size. Resistance in F1 seed also provides a better indicator of useful resistance than in the original accession. In season two, F1 ears are inoculated with Aspergillus flavus and screened for aflatoxin and fumonisin contamination. Screening nurseries are conducted in conventional 38-inch row spacings on a Norwood silt loam soil at the Dean Lee Research Station in central Louisiana by Dr. Steven Moore, LSU Ag Center corn breeder. A randomized complete block design is used with two replications. Each replication will include resistant checks of B73:Mp313e and B73:Tex6. The experimental unit is ten ears from a single row. Ears will be inoculated with A. flavus spores after anthesis using a hand-held pin bar apparatus dipped in a container containing spores in liquid suspension (about or equal to 90 million spores/ml). Ears will be harvested after physiological maturity, dried, ground to a fine meal and sent to the USDA-ARS facility at Stoneville, Mississippi, for aflatoxin and fumonisin analyses by Dr. Hamed Abbas, USDA Research Pathologist. Dr. Abbas will also maintain inoculum and provide spore suspensions at the time of anthesis. Resistance will be assessed by Dr. Moore. To date, 1600 lines from the North American Plant Intoduction Center have been planted in nurseries at Alexandria, LA, although many have not been successfully pollinated and screened. Step two: Develop Breeding Populations - Seed from accessions showing the lowest aflatoxin will be screened again to confirm resistance. Selected accessions crossed to B73 will be selfed to the F4 generation. Resistant and non-resistant populations will be identified and planned for use in commercial marker-assisted programs where resistance can be transferred into elite inbreds. Eleven lines with potentially improved resistance are now being advanced (Nigerian Composite B. Manio-PI490411, Haiti 33- PI483902, Saint Croix1-PI484036, TZI18-PI506253, Tx81, Tx807 and CML43- PI595535). Step three: Transfer Improved Resistance into Commerical Inbreds. Significant Activities that Support Special Target Populations New genes are needed to develop corn hybrids with resistance to Aspergillus flavus and aflatoxin biosynthesis. To date, 1,900 lines obtained from the North Central Regional Plant Introduction Station in Ames, IA, have been planted at the Dean Lee Research Station in an effort to identify new resistance to aflatoxin biosynthesis. In order to increase ear size, corn lines are first crossed to B73. The F1 seed are screened for aflatoxin in the second season by inoculating ears in two replicated rows. Thirty-four accessions have now been identified that recorded low aflatoxin relative to resistant checks. Over thirty corn lines, along with resistant checks �Mp313e� and �Tex6� were hybridized with B73. Seed from the F1 hybrids were planted in replicated field trials at three locations in Louisiana in 2008, although there was not enough seed to plant all hybrids and/or all reps at each location. We hope to determine this summer if we have identified sources of superior resistance. If so, we will plan to immediately proceed to incorporate the resistance into commercial material. The thirty-four lines planted at one or more locations in 2008 are �Nigerian Composite B�, �Manio�, �Lancaster Surecrop�, �Haiti 33�, �Saint Croix 1�, �Dominican Republic 309�, �Tx81�, �Tx807�, �CML91�, �Brazil 1135-AF�, �Brazil 1088-AF�, �BENZ 745�, �Veracruz 59�, �Jalisco 38�, �BENZ 755�, �SE 028�, �31116 G M37W2T/A�, �Veracruz 200�, �Chihuahua 230�, �Brazil 1483�, �Durango 84�, �Brazil 2797�, �Hidalgo 17�, �Veracruz 119�, �Sao Paulo Group 9�, �Chihuahua 75�, �Veracruz 130�, �Brazil 1519�, �CML 43�, �P 69�, �TZ118 (Nigeria)�, �Benz 875�, �CML 271�, and �Coahuila 21�. The ADODR monitors the activities of this project through frequent telephone and email communications.
Impacts
(N/A)
Publications
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Progress 10/01/06 to 09/30/07
Outputs
Progress Report Objectives (from AD-416) The objective of this cooperative research project is to enhance the development of mycotoxin-resistant corn hybrids by identifying new resistant genes from world collections and incorporating them into existing breeding programs. Approach (from AD-416) Three major steps are outlined to improve resistance of commercial hybrids to aflatoxin biosynthesis. The first is large scale screening of corn germplasm (accessions) to identify new resistance. The second is to stabilize newfound resistance into improved populations. The third is to transfer resistance into commercial inbreds. Step one: Screen Corn Germplasm for Improved Resistance. Our screening procedure requires two seasons. In season one corn accessions are hybridized with B73 to produce F1 seed. Mr. Mark Millard, Maize Curator at the North American Plant Introduction Center in Ames, Iowa, will share responsibility to select accessions for screening and provide seed. Initial priority will be given to accessions originating from hot and dry climates where active or passive selection for resistance might have occurred. Accessions will be hybridized B73 to produce F1 seed in summer nurseries at Alexandria, Louisiana. B73 has been perhaps the most widely recognized corn inbred and represents one side of the most common heterozygous hybrid combination. Accessions hybridized with B73 produce F1 seed with improved vigor and ear size. Resistance in F1 seed also provides a better indicator of useful resistance than in the original accession. In season two, F1 ears are inoculated with Aspergillus flavus and screened for aflatoxin and fumonisin contamination. Screening nurseries are conducted in conventional 38-inch row spacings on a Norwood silt loam soil at the Dean Lee Research Station in central Louisiana by Dr. Steven Moore, LSU Ag Center corn breeder. A randomized complete block design is used with two replications. Each replication will include resistant checks of B73:Mp313e and B73:Tex6. The experimental unit is ten ears from a single row. Ears will be inoculated with A. flavus spores after anthesis using a hand-held pin bar apparatus dipped in a container containing spores in liquid suspension (about or equal to 90 million spores/ml). Ears will be harvested after physiological maturity, dried, ground to a fine meal and sent to the USDA-ARS facility at Stoneville, Mississippi, for aflatoxin and fumonisin analyses by Dr. Hamed Abbas, USDA Research Pathologist. Dr. Abbas will also maintain inoculum and provide spore suspensions at the time of anthesis. Resistance will be assessed by Dr. Moore. To date, 1600 lines from the North American Plant Intoduction Center have been planted in nurseries at Alexandria, LA, although many have not been successfully pollinated and screened. Step two: Develop Breeding Populations - Seed from accessions showing the lowest aflatoxin will be screened again to confirm resistance. Selected accessions crossed to B73 will be selfed to the F4 generation. Resistant and non-resistant populations will be identified and planned for use in commercial marker-assisted programs where resistance can be transferred into elite inbreds. Eleven lines with potentially improved resistance are now being advanced (Nigerian Composite B. Manio-PI490411, Haiti 33- PI483902, Saint Croix1-PI484036, TZI18-PI506253, Tx81, Tx807 and CML43- PI595535). Step three: Transfer Improved Resistance into Commerical Inbreds. Significant Activities that Support Special Target Populations This report serves to document research on Screening Global Corn Accessions to find New Genes with Resistance to Aflatoxin and Fumonisin conducted under a Specific Cooperative Agreement between ARS and Louisiana State University. Additional details of the research can be found in the report for the in-house project 6402-42000-003-00D, "Agricultural Practices, Ecological and Varietal Effects on Aflatoxins and Other Mycotoxins in Corn." New genes are needed to develop corn hybrids with resistance to Aspergillus flavus and aflatoxin biosynthesis. Eleven lines were selected which may have superior resistance. These are �Nigerian Composite B�, �Manio�, �Lancaster Surecrop�, PI 218189, �Haiti 33�, �Saint Croix 1�, �Dominican Republic 309�, PI 506253, �Tx81�, �Tx807�, and PI 595535. These lines were crossed-pollinated to B73 and Mo17 in 2006 in an effort to stabilize resistance in an improved agronomic background. Seed from successful pollinations were planted in a winter nursery facility at Homestead Florida (2006-2007). Seed from these lines were planted in 2007 at the Dean Lee Research Station at Alexandria, LA, in 2007 and are now in the field approaching maturity and/or harvest. Twenty-one accessions were selected in 2006 that had lower aflatoxin mathematically than resistant checks: �CML91�, �Brazil 1135-AF�, �Brazil 1088-AF�, �BENZ 745�, �Veracruz 59�, �Jalisco 38�, �BENZ 755�, �SE 028�, �31116 G M37W2T/A�, �Veracruz 200�, �Chihuahua 230�, �Brazil 1483�, �Durango 84�, �Brazil 2797�, �Hidalgo 17�, �Veracruz 119�, �Sao Paulo Group 9�, �Chihuahua 75', �Veracruz 130�, �Brazil 1519� and �Coahuila 21�. Seed from successful crosses and/or self-pollinations of these lines are now being moved forward in a 2007 summer nursery at the Dean Lee Research Station in Alexandria, LA. The work by the cooperator was monitored via e-mail, phone calls, visiting the collaborator by the ARS scientist on June 13 Field Day, and round table discussion at the aflatoxin workshop annual meeting in October in 2006.
Impacts
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