Progress 09/26/03 to 09/25/09
Outputs
OUTPUTS: During the 2009 crop year we continued selection, evaluation and characterization of diverse maize germplasm to identify inbred lines with reduced preharvest aflatoxin accumulations, reduced affects from abiotic stress, adaptation to the Southern U.S. and overall agronomic performance. The 2009 breeding nursery consisted of approximately 1200 yellow maize breeding plots, 250 each of white and QPM breeding plots 100 red and blue breeding plots, and 500 genetics plots (photoperiod sensitivity, perennialism, etc.). Breeding plot primary selection criteria were 1. plant desirability, including 1a. height, 1b. flowering time, 1c. staygreen, and 1d. lack of foliar diseases (rust, leaf blight); 2) improved husk coverage including 2a) good ear tip coverage, and 2b) tight husks; and 3) ear desirability at harvest including 3a) no ear rots (A. flavus, A. niger, Penecillium, smut, Fusarium, or others) 3b) a high number of kernel rows, 3b) good ear length, 3c) decent kernel size, 3d) high ear heft (when dry), 3e) grain color (where appropriate). From these selections a total of 764 plots (derived from approximately 670 ears) of promising breeding and genetics material was sent to the winter nursery in Weslaco, TX. Additionally, 390 plots were planted in two isolation blocks (SS, NSS) to create testcross hybrids for further evaluation. Multilocational hybrid yield trials were planted across south and central Texas and the evaluation under inoculation with Aspergillus flavus aided in further characterization of these lines. Over the life of this project, in addition to breeding, testing and training activities, two QTL mapping studies were conducted on a recombinant inbred line population derived from a cross between B73o2o2 (temperate opaque 2 line with high aflatoxin accumulations) and CML161 (a tropical adapted line with low aflatoxin accumulation). The first QTL study evaluated inbred lines per se. The second study conducted in 2008 and 2009 evaluated hybrid testcrosses of this same material as both a QTL study (genetics) and a breeding line study each planted in three locations. Yield trials of this population under inoculation with Aspergillus flavus were evaluated in Weslaco, TX (390 plots); College Station, TX (480 plots) and Corpus Christi, TX (390 plots). In College Station and Weslaco stress was applied by withholding irrigation. In Corpus Christi, the trial was planted late due to lack of sufficient soil moisture and to induce late season drought and heat stress but eventually abandoned because the drought became to severe. Data on aflatoxin, grain yield, plant and ear height, flowering time, lodging, oil, starch, protein, were taken and identified the most promising of these lines. PARTICIPANTS: Kerry Mayfield (Senior Research Associate), Seth Murray (Assistant Professor), Javier Betran (Professor), Meghyn Stalcup (Masters Student), William Rooney (Professor), Thomas Isakeit (Professor), Wenwei Xu (Professor), Gary Odvody (Professor), Dennis Pietsch (Senior Research Associate), Jurg Blumenthal (Professor) TARGET AUDIENCES: Texas and US corn producers, corn breeding companies and corn seed companies, students, and the public. PROJECT MODIFICATIONS: This is the final report for this project. The new project is CRIS NUMBER: 0219546 (PROJECT NUMBER: TEX09348) and has changed focus to reflect a new primary investigator (Murray).
Impacts
Throughout the life of this project at least six students were trained and educated. Over 90 inbred lines were developed and deemed to have sufficient improvements or novel characteristics to warrant release. Five QTL were identified for aflatoxin resistance and 26 QTL were identified for starch oil and protein across different environments that could be incorporated into producers inbreds and hybrids through marker assisted selection.
Publications
- Pietsch, D., J. Blumenthal, K.L. Mayfield, S. Labar, S.C. Murray. 2009. Corn Performance Tests in Texas. #SCS-2009-18. Texas AgriLife Research. College Station, TX.
- Murray, S.C., K.L. Mayfield, M.B. Stalcup, T. Isakeit. 2009. Quantitative Genetics and Maize Breeding for Texas. Plant Breeding Coordinating Committee National Conference. Madison, WI. August 3-5.
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Progress 01/01/08 to 12/31/08
Outputs
OUTPUTS: During the 2008 crop year we continued selection, evaluation and characterization of diverse maize germplasm to identify inbred lines with reduced preharvest aflatoxin accumulations, reduced affects from abiotic stress, adaptation to the Southern U.S. and overall agronomic performance. Multilocation trials across south and central Texas and evaluation under inoculation with Aspergillus flavus have aided in characterization of these lines. Approximately 350 testcrosses were planted at multiple locations across the southern U.S. and Texas. Multiple traits (grain yield, test weight, moisture, maturity, plant and ear height, root and stalk lodging) were evaluated at each location to aid in determining the most adapted germplasm for these growing environments. Several hybrid testcrosses in the yellow trials exhibited adaptation similar to that of the commercial checks used to compare. These germplasm are derived from crosses which include tropical and subtropical sources and exhibit long tight husks and hard flinty endosperm. Two nurseries were utilized during 2008 to advance breeding generations and to make selections. The regular season nursery in College Station consisted of 1100 breeding rows divided between yellow, white and qpm germplasm and lines. The off season nursery at Weslaco consisted of 610 rows for advancing generations and creating new hybrid combinations. Approximately 500 inbred lines representing a wide range of maturity (early, medium and late), kernel texture (hard vs. soft), husk coverage (long and tight vs. short and loose), color (yellow, white), adaptation (tropical, subtropical, temperate), stalk and root soundness (lodging) and quality (high lysine). The most promising germplasm was selected by traits such as maturity, stalk and root soundness, kernel texture and color. Texas environments tend to be a transitional area for exotic germplasm. This transitional area allows for the introgression of tropical alleles which could not be accomplished in more temperate areas. We are searching for new alleles for reducing preharvest aflatoxin accumulations, adaptation to Texas environment, kernel texture and foliar disease resistance; this transitional area has allowed us to tap into the tropical germplasm pool to potentially access new alleles for these traits. Development of corn germplasm utilizing both tropical germplasm with its stress tolerance and kernel qualities and temperate germplasm with its high yield potential and known heterotic response, should help bring desirable allele combinations to Texas corn growing regions. PARTICIPANTS: Kerry Mayfield, Dr. Seth Murray, Dr. William Rooney and Dale Herrington participated in planting, pollination, harvesting, phenotyping, and data analysis/ evaluation. Kind support was provided with collaborators Dr. Thomas Isakeit and Dr. Gary Odvody. TARGET AUDIENCES: Through field days and site visits, Texas corn producers were introduced to research, germplasm, and outputs conducted under this project. PROJECT MODIFICATIONS: This project will be replaced with project Tex09348.
Impacts
Several potential quantitative trait loci (QTL) for reduction of aflatoxin, oil, protein and starch were identified in a recombinant inbred line population testcrosses. Introgression of these alleles should aid in reducing abiotic/biotic stresses in the Southern U.S. and increase the diversification of corn germplasm in the U.S.
Publications
- No publications reported this period
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Progress 01/01/07 to 12/31/07
Outputs
During the 2007 season we have continued evaluation, characterization and selection of diverse corn germplasm to develop inbred lines with lowered susceptibility to aflatoxin, adaptation to Southern U.S. environment, tolerance to abiotic stress and improved agronomic performance. Multilocation evaluations across south and central Texas and evaluations under inoculation with Aspergillus flavus have aided in better characterization of these germplasm. Approximately 300 experimental hybrids and testcrosses were evaluated across several Texas and Southern U.S. environments; multiple traits (yield, test weight, moisture, stand, root and stalk lodging, plant and ear heights) measured help identify the most adapted germplasm for the local conditions. Considering overall performance, we have selected the best material for continuation in the program as parental lines. Most of this germplasm has subtropical or tropical origins, exhibiting hard endosperm and long and tight
husks. We again had two breeding nurseries during 2007, one regular season nursery at College Station (1700 plots) and an off season nursery at Weslaco (500 plots). Approximately 500 inbred lines representing a wide range of maturities (early, intermediate and late), adaptation (topical, subtropical and temperate), color (white and yellow), quality (lysine content) and kernel characteristics (flint, dent) were screened in the nurseries. The most promising germplasm in the nurseries were classified by traits such as maturity, kernel texture, cob color, lodging and plant and ear heights. We are searching for new alleles to aid in reductions of mycotoxins (aflatoxins and fumonisin) contamination, adaptation to the Texas environment, kernel attributes, disease resistance; exotic germplasm has aided in this search. Texas environment tends to be a transitional area for tropical and temperate germplasm. This transitional area allows for the introgression of alleles from tropical sources
which otherwise could not be accomplished in the more temperate areas. Temperate types of corn tend to provide known heterotic response, high yields and stalk strength, while subtropical and tropical corn ten to provide good stress tolerance and kernel quality. The development of inbreds utilizing both sources of germplasm should help bridge the gap of genetic flow between the gene two pools of genetic materials.
Impacts
The introgression of these alleles should aid in reducing abiotic/biotic stresses in the Southern U.S. and increase the diversification of corn germplasm in the U.S.
Publications
- Mayfield, K.L., T. Isakeit, Gary Odvody, W.L. Rooney. 2007. Breeding Corn Germplasm for Reduced Aflatoxin Contamination. Aflatoxin Elimination Workshop 2007. October 21-25. Atlanta, GA.
- K. Mayfield, T. Isakeit, W. Xu, D. White, W. B. Henry, G.L. Windham, W. P. Williams, B. Guo, H. Abbas, S. Moore, Q.J. Raab, D. P. Gorman, J.M. Perkins, R. D. Lee, and M.D. Krakowsky. 2007. SERAT: The Southeast Region Aflatoxin Trial. Aflatoxin Elimination Workshop 2007. October 21-25. Atlanta, GA.
- Isakeit, T., K. Mayfield, R. Sutton, K. Ong, and J.W. Dorner. 2007. Reduction in Aflatoxin Contamination of Corn in Texas with Aflaguard (Aspergillus flavus NRRL 21882). Aflatoxin Elimination Workshop 2007. October 21-25. Atlanta, GA.
- Michael Kolomiets, Xiquan Gao, Shawn Christensen, Yong-Soon Park, Tom Isakeit, Javier Betran, Kerry Mayfield, Won-Bo Shim, Jurgen Engelberth, Cornelia Gobel, Marion Brodhagen, Ivo Feussner, and Nancy Keller. 2007. Maize lipoxygenases govern production of conidia and mycotoxins by Aspergillus flavus and Fusarium verticillioides. Aflatoxin Elimination Workshop 2007. October 21-25. Atlanta, GA.
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Progress 01/01/06 to 12/31/06
Outputs
During the 2006 season we have continued the evaluation, characterization and selection of corn germplasm with different origins and genetic backgrounds to develop inbred lines with superior grain quality, reduced susceptibility to aflatoxin, adaptation to Texas, and tolerance to abiotic stresses. We have conducted multilocation testing across the major corn production regions of Texas and evaluated germplasm under drought stress and inoculation with Aspergillus flavus, fungi responsible of aflatoxin contamination in corn. Approximately 800 experimental hybrids and testcrosses were evaluated across several Texas environments to identify the most adapted germplasm to the local conditions. Different traits (yield, maturity, moisture, test weight, lodging, ear and plant height, cob and grain color, texture, disease resistance, etc.) were recorded. We have selected the best material in these trials considering its overall performance, local adaptation, and quality. Most
of these inbreds have subtropical or tropical origin and hard endosperm (e.g., LAMA lines). In these evaluations we have collaborated with other public programs and agencies, international centers, and private seed companies. As in previous years, during year 2006 we had two nurseries, one during the regular season (summer) at College Station (4,000 plots) and one off-season (winter) at Weslaco (1000 plots). An approximate of 1000 inbred lines representing a wide range of maturities (early, intermediate and late), adaptation (tropical, subtropical and temperate), color (white, yellow, orange), quality (lysine content), and kernel characteristics (flint, dent) were screened in these nurseries. Traits such as early vigor, maturity, adaptation, plant and ear height, grain color, cob color, texture, disease resistance, and ear characteristics were recorded and ultimately used to classify and select the most promising germplasm for our program objectives. We are searching for new alleles
in exotic germplasm for resistance to mycotoxins, tolerance to drought and heat, high test weight, high proportion of hard flinty endosperm, kernel integrity with kernels free of fissures or stress cracks, white cobs, and nutritional value for food or feed. Transitional areas between tropical and temperate areas, such as Texas, represent excellent opportunities to incorporate, combine and introgress exotic germplasm in temperate material and vice versa. By developing inbreds adapted to Southern U.S. we expect to facilitate the connection and genetic flow between these gene pools. Overall, temperate inbreds from northern areas provide high yield, stalk quality, known heterotic response, and early vigor while tropical and subtropical germplasm from southern areas provides resistance and/or tolerance to biotic and abiotic stresses (e.g.,less aflatoxin, drought and heat tolerance) and kernel quality (more flinty endosperm texture). There are several lines in advance stages of testing that
will be proposed for release during 2007.
Impacts
With the development of this material we expect to contribute to the diversity of corn germplasm in the U.S. and to the improvement of corn hybrids for sustainable productivity, value-added profitability and food safety.
Publications
- Javier Betran, Sandeep Bhatnagar, Tom Isakeit, Gary Odvody and Kerry Mayfield. 2006. Aflatoxin accumulation and associated traits in QPM maize inbreds and their testcrosses. Euphytica 152:247-257.
- Leilani A. Robertson-Hoyt, Javier Betran, Gary A. Payne, Don G. White, Thomas Isakeit, Chris M. Maragos, Terence L. Molnar, and James B. Holland. 2006. Relationships among responses to Fusarium and Aspergillus ear rots and contamination by fumonisin and aflatoxin in maize (Zea mays). Phytopath. (Accepted).
- F.J. Betran, K. Mayfield, T. Isakeit, and M. Menz. 2005. Breeding exotic maize germplasm. Proceedings of the Arnel R. Hallauer International Plant Breeding Symposium. Mexico D.F., Mexico 2003. Iowa State Press.
- F.J. Betran, T. Isakeit, G. Odvody, and K. Mayfield. 2006. Breeding corn germplasm for agronomic performance and reduced aflatoxin contamination 2006. Aflatoxin Elimination Workshop 2006, October 16 to 18, Forth Worth, Texas.
- Cody Mckee, Kerry Mayfield, Tom Isakeit, Gary Odvody, and Javier Betran. 2006. Multilocation evaluation of aflatoxin accumulation and agronomic performance of maize hybrids in Texas. Aflatoxin Elimination Workshop 2006, October 16 to 18, Forth Worth, Texas.
- Matthew Krakowsky, Baozhu Guo, Don White, Wenwei Xu, Paul Williams, Tom Brooks, Gary Windham, Steve Moore, Hamed Abbas, James Perkins, Daniel Gorman, Quinton Raab, Keith Arnold, David Smith, Tom Isakeit, Kerry Mayfield and Javier Betran. 2006. Southern East Regional Aflatoxin Test (SERAT) 2006. Aflatoxin Elimination Workshop 2006, October 16 to 18, Forth Worth, Texas.
- Rebecca Corn, Matt Krakowsky, Paul Williams, David Bergvinson, Kerry Mayfield and Javier Betran. 2006. Response to aflatoxin of exotic (CIMMYT and LAMA) germplasm in Southern USA. Aflatoxin Elimination Workshop 2006, October 16 to 18, Forth Worth, Texas.
- Halima Atta, Andres Gutierrez, Monica Menz, Tom Isakeit, Kerry Mayfield and Javier Betran. 2006. Mapping of QTL for response to aflatoxin accumulation. Aflatoxin Elimination Workshop 2006, October 16 to 18, Forth Worth, Texas.
- D. Makumbi, F.J. Betran, M. Banziger, and J.M. Ribaut. 2006. Heterosis and genetic diversity of tropical inbreds under stress and optimal conditions. Drought Conference, Keystone, Colorado, April 2006.
- R. Corn, K. Mayfield, C. McKee, T. Isakeit, G. Odvody and J. Betran. 2006. Introduction and Adaptation of Corn Exotic Lines to Southern U.S. Agronomy abstracts, Indianapolis, IN.
- K. Mayfield, T. Isakeit, G. Odvody, and F.J. Betran. 2006. Interaction between host plant genotypes and A. flavus strains across environments and years. Agronomy abstracts, Indianapolis, IN.
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Progress 01/01/05 to 12/31/05
Outputs
During the 2005 season we have continued the evaluation, characterization and selection of corn germplasm with different origins and genetic backgrounds to develop inbred lines with superior grain quality, reduced susceptibility to aflatoxin, adaptation to Texas, and tolerance to abiotic stresses. We have conducted multilocation testing across the major corn production regions of Texas and evaluated germplasm under drought stress and inoculation with Aspergillus flavus, fungi responsible of aflatoxin contamination in corn. Approximately 800 experimental hybrids and testcrosses were evaluated across several Texas environments to identify the most adapted germplasm to the local conditions. Different traits (yield, maturity, moisture, test weight, lodging, ear and plant height, cob and grain color, texture, disease resistance, etc.) were recorded. We have selected the best material in these trials considering its overall performance, local adaptation, and quality. Most
of these inbreds have subtropical or tropical origin and hard endosperm (e.g., LAMA lines). In these evaluations we have collaborated with other public programs and agencies, international centers, and private seed companies. As in previous years, during year 2005 we had two nurseries, one during the regular season (summer) at College Station (5,000 plots) and one off-season (winter) at Weslaco (4,000 plots). An approximate of 1000 inbred lines representing a wide range of maturities (early, intermediate and late), adaptation (tropical, subtropical and temperate), color (white, yellow, orange), quality (lysine content), and kernel characteristics (flint, dent) were screened in these nurseries. Traits such as early vigor, maturity, adaptation, plant and ear height, grain color, cob color, texture, disease resistance, and ear characteristics were recorded and ultimately used to classify and select the most promising germplasm for our program objectives. We are searching for new alleles
in exotic germplasm for resistance to mycotoxins, tolerance to drought and heat, high test weight, high proportion of hard flinty endosperm, kernel integrity with kernels free of fissures or stress cracks, white cobs, and nutritional value for food or feed. Transitional areas between tropical and temperate areas, such as Texas, represent excellent opportunities to incorporate, combine and introgress exotic germplasm in temperate material and vice versa. By developing inbreds adapted to Southern U.S. we expect to facilitate the connection and genetic flow between these gene pools. Overall, temperate inbreds from northern areas provide high yield, stalk quality, known heterotic response, and early vigor while tropical and subtropical germplasm from southern areas provides resistance and/or tolerance to biotic and abiotic stresses (e.g.,less aflatoxin, drought and heat tolerance) and kernel quality (more flinty endosperm texture). There are several lines in advance stages of testing that
will be proposed for release during 2006.
Impacts
With the development of this material we expect to contribute to the diversity of corn germplasm in the U.S. and to the improvement of corn hybrids for sustainable productivity, value-added profitability and food safety.
Publications
- F.J. Betran, T. Isakeit, G. Odvody, and K. Mayfield. 2005. Breeding corn germplasm for agronomic performance and reduced aflatoxin contamination. Aflatoxin Elimination Workshop 2005, October 24-26, 2005, Raleigh, NC.
- K. Mayfield, T. Isakeit, G. Odvody, and F.J. Betran. 2005. Interaction between A. flavus strains and host plant genotypes across environments and years. Aflatoxin Elimination Workshop 2005, October 24-26, 2005, Raleigh, NC.
- C. McKee, T. Isakeit, G. Odvody, K. Mayfield, and F.J. Betran. 2005. Multilocation evaluation of aflatoxin accumulation in yellow maize hybrids. Aflatoxin Elimination Workshop 2005, October 24-26, 2005, Raleigh, NC.
- F.J. Betran, T. Isakeit, G. Odvody, and K. Mayfield. 2005. Breeding Corn to Reduce Preharvest Aflatoxin Contamination. In Aflatoxin and Food Safety. H. Abbas (ed.). Marcel Dekker, Inc. New York.
- M. Clements, P. Williams, S. Moore, M. Krakowsky, B. Guo, D. White, W. Xu, T. Isakeit, T. Brooks, G. Windham, H. Abbas, J. Perkins, D. Gorman, Q. Raab, K. Arnold, D. Smith, and F.J. Betran. 2005. Southern East Regional Aflatoxin Test (SERAT). Aflatoxin Elimination Workshop 2005, October 24-26, 2005, Raleigh, NC.
- D. Jeffers, M. Krakowsky, P. Williams, and F.J. Betran. 2005. Evaluation of CIMMYT germplasm for response to aflatoxin production in the Southern USA. Aflatoxin Elimination Workshop 2005, October 24-26, 2005, Raleigh, NC.
- M. Edwards, M. Menz, T. Isakeit, and F.J. Betran. 2005. Phenotypic and genotypic characterization of a RIL maize mapping population for aflatoxin and secondary traits. Aflatoxin Elimination Workshop 2005, October 24-26, 2005, Raleigh, NC.
- F.J. Betran, T. Isakeit, S. Bhatnagar, M. Edwards, B. Ochs, K. Mayfield, C. McKee, H. Atta, G. Odvody and M. Menz. 2005. Breeding for aflatoxin resistance and protein quality in maize. 2nd general meeting of The Rockefeller Foundation: Biotechnology, Breeding and Seed Systems for African Crops. Nairobi, Kenya, January 2005.
- D. Jeffers, D. Makumbi, F.J. Betran, R. Brown, D. Bergvison, and M. Banziger. 2005. Breeding for Aflatoxin Resistance in Maize. International Conference: Reducing Impact Of Mycotoxins In Tropical Agriculture With Emphasis On Health And Trade In Africa. Accra, Ghana, September 2005.
- D. Makumbi, M. Banziger, J-M. Ribaut, and F.J. Betran. 2005. Combining Ability, Heterosis and Stability of Tropical Maize Inbreds under Stress and Optimal Conditions. II Interdrought Conference, Rome, Italy, September 2005.
- O. Leyva, A. Gutierrez, F.J. Betran, K. Mayfield, and A. Carballo. 2005. Quantification of maize kernels components using digital image processing. In Agronomy Abstracts. Salt Lake City, UT.
- M.L. Warburton, J.M. Ribaut1, J. Franco, J. Crossa1, P. Dubreuil, and F.J. Betran. 2005. Genetic characterization of 218 elite CIMMYT maize inbred lines using RFLP markers. Euphytica 142:97-104.
- F.J. Betran, T. Isakeit, G. Odvody, and K. Mayfield. 2005. Breeding Corn to Reduce Preharvest Aflatoxin Contamination. In Aflatoxin and Food Safety. H. Abbas (ed.). Marcel Dekker, Inc. New York.
- C. McKee, B. Ochs, K. Mayfield, and F.J. Betran. 2005. Aflatoxin Accumulation and Agronomic Performance of Corn Hybrids Across Environments. In Agronomy Abstracts. Salt Lake City, UT.
- B. Ochs, C. Mckee, K. Mayfield, and F.J. Betran. 2005. Agronomic performance and grain attributes of Argentine maize hybrids in Southern U.S. In Agronomy Abstracts. Salt Lake City, UT.
- D. Makumbi, M. Banziger, J-M. Ribaut, and F.J. Betran. 2005. Combining Ability and Heterosis in Tropical Maize Inbreds under Stress and Optimal Conditions. In Agronomy Abstracts. Salt Lake City, UT.
- H. Atta, M. Menz, T.Isakeit, and F.J. Betran. 2005. Phenotypic evaluation of a high lysine maize recombinant inbred line population. In Agronomy Abstracts. Salt Lake City, UT.
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Progress 01/01/04 to 12/31/04
Outputs
During the 2004 season we have continued the evaluation, characterization and selection of corn germplasm with different origins and genetic backgrounds to develop inbred lines with superior grain quality, reduced susceptibility to aflatoxin, adaptation to Texas, and tolerance to abiotic stresses. We have conducted multilocation testing across the major corn production regions of Texas and evaluated germplasm under drought stress and inoculation with Aspergillus flavus, fungi responsible of aflatoxin contamination in corn. Approximately, 1000 experimental hybrids and testcrosses were evaluated across several Texas environments to identify the most adapted germplasm to the local conditions. Different traits (yield, maturity, moisture, test weight, lodging, ear and plant height, cob and grain color, texture, disease resistance, etc.) were recorded. We have selected the best material in these trials considering its overall performance, local adaptation, and quality. Most
of these inbreds have subtropical or tropical origin and hard endosperm (e.g., LAMA lines). In these evaluations we have collaborated with other public programs and agencies, international centers, and private seed companies. During year 2004 we had two nurseries, one during the regular season (summer) at College Station, TX (5,000 plots) and one off-season (winter) at Weslaco, TX (4,000 plots). An approximate of 1000 inbred lines representing a wide range of maturities (early, intermediate and late), adaptation (tropical, subtropical and temperate), color (white, yellow, orange), quality (lysine content), and kernel characteristics (flint, dent) were screened in these nurseries. Traits such as early vigor, maturity, adaptation, plant and ear height, grain color, cob color, texture, disease resistance, and ear characteristics were recorded and ultimately used to classify and select the most promising germplasm for our program objectives. We are searching for new alleles in exotic
germplasm for resistance to mycotoxins, tolerance to drought and heat, high test weight, high proportion of hard flinty endosperm, kernel integrity with kernels free of fissures or stress cracks, white cobs, and nutritional value for food or feed. Transitional areas between tropical and temperate areas, such as Texas, represent excellent opportunities to incorporate, combine and introgress exotic germplasm in temperate material and vice versa. By developing inbreds adapted to Southern U.S. we expect to facilitate the connection and genetic flow between these gene pools. Overall, temperate inbreds from northern areas provide high yield, stalk quality, known heterotic response, and early vigor while tropical and subtropical germplasm from southern areas provides resistance and/or tolerance to biotic and abiotic stresses (e.g.,less aflatoxin, drought and heat tolerance) and kernel quality (more flinty endosperm texture). The releases of three parental inbred lines (Tx110, Tx114, and
Tx772) and 4 germplasm lines (Tx745, Tx714, Tx732 and Tx770) were published in Crop Science during 2004.
Impacts
With the development of this material we expect to contribute to the diversity of corn germplasm in the U.S. and to the improvement of corn hybrids for sustainable productivity, value-added profitability and food safety.
Publications
- F.J. Betran, T. Isakeit, G. Odvody, K. Mayfield, D. Transue, S. Bhatnagar, D. Makumbi, and R. Ganunga. 2004. Response of white food corn to aflatoxin contamination. Mycopathologia 157(4).
- B. Ochs, K. Mayfield, and F.J. Betran. 2004. Performance of Argentine maize hybrids across southern U.S. environments. In Agronomy Abstracts. Seattle, WA.
- B. Ochs, K. Mayfield, and F.J. Betran. 2004. Testcrosses between exotic maize lines and elite temperate testers. In Agronomy Abstracts. Seattle, WA.
- K. Mayfield, H. Atta, C. Mckee, and F.J. Betran. 2004. Agronomic performance of specialty corn in Texas. In Agronomy Abstracts. Seattle, WA.
- M. Edwards, M. Menz, and F.J. Betran. 2004. Phenotypic evaluation of a maize recombinant inbred line population. In Agronomy Abstracts. Seattle, WA.
- S. Bhatnagar, M. Menz, and F.J. Betran. 2004. Haplotyping of maize chromosome 7 in high lysine inbreds. In Agronomy Abstracts. Seattle, WA.
- F.J. Betran, A. Bockholt, F. Fojt III, D. Pietsch, L. Rooney, and K. Mayfield. 2004. Registration of Tx114. Crop Sci. 44: 1036.
- F.J. Betran, A. Bockholt, F. Fojt III, and K. Mayfield. 2004. Registration of Tx110. Crop Sci. 44: 1035-1036.
- C.F. Llorente, F.J. Betran, A. Bockholt, and F. Fojt III. 2004. Registration of Tx772. Crop Sci. 44: 1036-1037.
- F.J. Betran, A. Bockholt, F. Fojt III, K. Mayfield, and D. Pietsch. 2004. Registration of Tx714 maize germplasm line. Crop Sci. 44:1028-1029.
- F.J. Betran, A. Bockholt, F. Fojt III, and K. Mayfield. 2004. Registration of Tx732 maize germplasm line. Crop Sci. 44:1028-1029.
- F.J. Betran, A. Bockholt, and F. Fojt III. 2004. Registration of Tx745 maize germplasm line. Crop Sci. 44: 1029.
- F.J. Betran, A. Bockholt, F. Fojt III, and K. Mayfield. 2004. Registration of Tx770 maize germplasm line. Crop Sci. 44: 1029-1030.
- F.J. Betran, and T. Isakeit. 2004. Aflatoxin accumulation in early, intermediate and late maturing maize hybrids. Agron. J. 96:565-570.
- Bhatnagar, S., F.J. Betran, and L.W. Rooney. 2004. Combining ability of quality protein maize inbreds. Crop Science 44: 1997-2005.
- Smith, C.W., Betran, F.J., and Runge, E. (eds.). 2004. Corn: origin, history, technology, and production. John Wiley & Sons, New York.
- F.J. Betran, T. Isakeit, G. Odvody, and K. Mayfield. 2004. Aflatoxin accumulation in maize inbreds and hybrids. Mycopathologia 157(4).
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Progress 01/01/03 to 12/31/03
Outputs
During the 2003 season we have continued the evaluation, characterization and selection of corn germplasm with different origins and genetic backgrounds to develop inbred lines with superior grain quality, reduced susceptibility to aflatoxin, adaptation to Texas, and tolerance to abiotic stresses. We have conducted multilocation testing across the major corn production regions of Texas and evaluated germplasm under drought stress and inoculation with Aspergillus flavus, fungi responsible of aflatoxin contamination in corn. Approximately 1000 experimental hybrids and testcrosses were evaluated across several Texas environments to identify the most adapted germplasm to the local conditions. Different traits (yield, maturity, moisture, test weight, lodging, ear and plant height, cob and grain color, texture, disease resistance, etc.) were recorded. We have selected the best material in these trials considering its overall performance, local adaptation, and quality. In
these evaluations we have collaborated with other public programs and agencies, international centers, and private seed companies. Inbred lines and their hybrids were evaluated under A. flavus inoculation in three locations in South and Central Texas during 2003. The most promising inbreds for reducing the risk of aflatoxin in Texas growing conditions are CML269, CML176, CML78, and Tx807 among the white grained lines, and TxX69's, CML323, Tx772, and CML288 among the yellow grained lines. Most of these inbreds have subtropical or tropical origin and hard endosperm. Their hybrids were more resistant to aflatoxin than commercial white food hybrids. During year 2003 we had two nurseries, one during the regular season (summer) at College Station (4,500 plots) and one off-season (winter) at Weslaco (4,000 plots). An approximate of 1000 inbred lines representing a wide range of maturities (early, intermediate and late), adaptation (tropical, subtropical and temperate), color (white, yellow,
orange), quality (lysine content), and kernel characteristics (flint, dent) were screened in these nurseries. Traits such as early vigor, maturity, adaptation, plant and ear height, grain color, cob color, texture, disease resistance, and ear characteristics were recorded and ultimately used to classify and select the most promising germplasm for our program objectives. We released three parental inbred lines (Tx110, Tx114, and Tx772) and 4 germplasm lines (Tx745, Tx714, Tx32 and Tx770) during 2003.
Impacts
With the development of this material we expect to contribute to the diversity of corn germplasm in the U.S. and to the improvement of corn hybrids for sustainable productivity, value-added profitability and food safety.
Publications
- F.J. Betran, A. Bockholt, F. Fojt III, L. Rooney. 2003. Registration of Tx811 Maize Parental Line. Crop Sci. 43: 1893-1894.
- F.J. Betran, A. Bockholt, F. Fojt III, G. Odvody. 2003. Registration of Tx807 Maize Parental Line. Crop Sci. 43: 1892-1893.
- F.J. Betran, A. Bockholt, F. Fojt III, R. Waniska. 2003. Registration of Tx802 Maize Parental Line. Crop Sci. 43: 1891-1892.
- F.J. Betran, D. Beck, M. Banziger, G. Edmeades. 2003. Genetic analysis of inbred and hybrid grain yield under stress and nonstress environments in tropical maize. Crop Sci 43:807-817.
- F.J. Betran, J.M. Ribaut, D. Beck, and D. Gonzalez de Leon. 2003. Genetic diversity, specific combining ability and heterosis in tropical maize under stress and non-stress environments. Crop Sci. 43:797-806.
- F.J. Betran, D. Beck, G. Edmeades, M. Banziger. 2003. Secondary Traits in Parental Inbreds and Hybrids under Stress and Non-stress Environments in Tropical Maize. Field Crops Research 83: 51-65.
- S. Bhatnagar, F.J. Betran, and D. Transue. 2003. Agronomic performance, aflatoxin accumulation and protein quality of subtropical and tropical QPM hybrids in southern USA. Maydica 48: 113-124.
- F. Maideni, C. Magorokosho, R. Ganunga, D. Makumbi, K. Mayfield, and F.J. Betran. 2003. Comparative performance of single and three-way white maize hybrids. In Agronomy Abstracts. Denver, CO.
- M.L. Edwards, K. Mayfield, T. Isakeit, G. Odvody, and F.J. Betran. 2003. Repeatability of aflatoxin trials in white and yellow maize. In Agronomy Abstracts. Denver, CO.
- S. Bhatnagar, P. Scott, K. Mayfield, and F.J. Betran. 2003. Agronomic and quality evaluations of high lysine maize hybrids. In Agronomy Abstracts. Denver, CO.
- K. Mayfield, D. Pietsch, J.M. Owen, and F.J. Betran. 2003. Classification and characterizatiopn of Texas corn locations based on yellow hybrid evaluations. In Agronomy Abstracts. Denver, CO.
- D.K. Transue, S. Bhatnagar, K. Mayfield, and F.J. Betran. 2003. Diallel analysis among temperate and subtropical white inbred testers: agronomic performance, heterotic response, and aflatoxin accumulation. In Agronomy Abstracts. Denver, CO.
- D.K. Transue, S. Bhatnagar, D. Pietsch, J. Owen, K. Mayfield, and F.J. Betran. 2003. Maize single cross hybrids between yellow temperate and subtropical and tropical inbreds. In Agronomy Abstracts. Denver, CO.
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Progress 01/01/02 to 12/31/02
Outputs
During the 2002 season we have continued the evaluation, characterization and selection of corn germplasm with different origins and genetic backgrounds to develop inbred lines with superior grain quality, reduced susceptibility to aflatoxin (AF), adaptation to Texas, and tolerance to abiotic stresses. We have conducted multilocation testing across the major corn production regions of Texas and evaluated germplasm under controlled drought stress and under inoculation with Aspergillus flavus, fungi responsible of aflatoxin production in corn. Approximately 500 experimental hybrids were tested across Texas to identify the most adapted germplasm to the local conditions. Different traits (yield, maturity, moisture, test weight, lodging, ear and plant height, cob and grain color, texture, disease resistance, etc.) were recorded. We have selected the best material in these trials considering its overall performance, local adaptation, and quality. In these evaluations we
have collaborated with other public programs and agencies, international centers, and private seed companies. Inbred lines and their hybrids were evaluated under inoculation in three locations in South and Central Texas: College Station (CS), Weslaco (WE), Corpus Christi (CC) during 2002. The most promising inbreds for reducing the risk of AF in Texas growing conditions are CML269, CML176, CML78, Tx130, and Tx807 among the white grained lines, and TxX69's, CML323, Tx772, and CML288 among the yellow grained lines. Most of these inbreds have subtropical or tropical origin and hard endosperm. Their hybrids were more resistant to AF than commercial white food hybrids. During year 2002 we had two nurseries, one during the regular season (summer) at College Station (4,000 plots) and one off-season (winter) at Weslaco (3,500 plots). An approximate of 1000 inbred lines representing a wide range of maturities (early, intermediate and late), adaptation (tropical, subtropical and temperate),
color (white, yellow, orange), quality (lysine content), and kernel characteristics (flint, dent) were screened in these nurseries. Traits such as early vigor, maturity, adaptation, plant and ear height, grain color, cob color, texture, disease resistance (i.e. aflatoxin), and ear characteristics were recorded and ultimately used to classify and select the most promising germplasm for our program objectives.
Impacts
With the development of this corn germplasm we have contributed to the to the diversity of corn germplasm in the U.S. and to the improvement of corn hybrids for sustainable productivity, value-added profitability and food safety.
Publications
- Kerry Mayfield, Javier Betran, Frank Fojt III, Dennis Pietsch. 2002. Comparative performance of early, intermediate and full season hybrids in Southern USA. In Agronomy Abstracts. Indianapolis, IN.
- Dennis Transue, Javier Betran, Sandeep Bhatnagar. 2002. Heterotic response of subtropical & tropical maize yellow inbreds across environments. In Agronomy Abstracts. Indianapolis, IN.
- Dennis Transue, Rosan Ganunga, Dan Makumbi, Javier Betran. 2002. Diallel analysis of F1 hybrids among white grained temperate, subtropical and tropical inbreds. In Agronomy Abstracts. Indianapolis, IN.
- F. J. Betran, T. Isakeit, and G. Odvody. 2002. Aflatoxin accumulation of white and yellow inbreds in diallel crosses. Crop Science 42: 1894-1901.
- Betran, F.J. and T. Isakeit. 2002. Aflatoxin contamination of early, intermediate, and late maturing maize hybrids. Mycopathologia 155:86.
- Betran, F.J., T. Isakeit, G. Odvody, and K. Mayfield. 2002. Maize germplasm evaluation for aflatoxin resistance in Texas. Mycopathologia 155:81.
- Betran, F.J., T. Isakeit, G. Odvody, and K. Mayfield. 2000. Aflatoxin accumulation in maize inbreds and hybrids. In Proc. of the Aflatoxin/Fumonisin Workshop 2002. October 23-25, 2002. San Antonio, TX.
- Betran, F.J., T. Isakeit, D. Transue, K. Mayfield, S. Bhatnagar, D. Makumbi, R. Ganunga, and D. Pietsch. 2002. Response of white food corn to aflatoxin accumulation. In Proc. of the Aflatoxin/Fumonisin Workshop 2002. October 23-25, 2002. San Antonio, TX.
- Bhatnagar, S., F. J. Betran, and D. Transue. 2002. Aflatoxin resistance of subtropical/tropical quality protein maize hybrids in Texas. Mycopathologia 155:85.
- F.J. Betran, S. Bhatnagar, L.W. Rooney and R.D. Waniska. 2002. Combining Abilities of Quality Protein Maize Inbreds. In Agronomy Abstracts. Indianapolis, IN.
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Progress 01/01/01 to 12/31/01
Outputs
During the 2001 season we have continued the evaluation, characterization and selection of corn germplasm with different origins and genetic backgrounds to develop inbred lines with superior grain quality, aflatoxin (AF) resistance, adaptation to Texas, and tolerance to abiotic stresses. We have conducted multilocation testing across the major corn production regions of Texas and evaluated germplasm under controlled drought stress and under artificial inoculation with Aspergillus flavus, fungi responsible of aflatoxin production in corn. We have maintained our cooperation with national and international institutions. Approximately 500 experimental hybrids were tested across Texas to identify the most adapted germplasm to the local conditions. Different traits (yield, maturity, moisture, test weight, lodging, ear and plant height, cob and grain color, texture, disease resistance, etc.) were recorded. The 2001 season has been good in general with timely rainfall, low
stress at flowering time, and low incidence of aflatoxin. We will select the best material in these trials considering its overall performance, local adaptation, and quality. In these evaluations we have collaborated with other public programs and agencies, international centers, and private seed companies. Also, we have continued as a cooperator of the U.S. Germplasm Enhancement Maize (GEM) project. Aflatoxin resistant candidate inbred lines and hybrids were tested under artificial inoculation in three Texas locations. We have identified white and yellow inbreds with consistent low AF accumulation in hybrid combinations. The most promising inbreds for our conditions were CML176, CML269, CML322, and Tx130 among the whites, and Tx601y, CML289, Tx770 and CML338 among the yellows. We will characterize further these genotypes, initiate the transfer of AF resistance to elite inbreds, and combine different types of aflatoxin resistance. Quality Protein Maize (QPM) and o2 hybrids were
evaluated in Texas environments. QPM in general had longer maturities, bigger tassels, higher ear placements, higher lodging, and better grain quality than temperate o2 hybrids and commercial checks. In addition, QPM hybrids had better husk cover, less ear rot, and were more resistant to aflatoxin as compared to non-QPM checks. QPM germplasm of subtropical background appears to be a promising source of AF resistant factors. During year 2001 we had two nurseries, one during the regular season (summer) at College Station (3,000 plots) and one off-season (winter) at Weslaco (2,500 plots). An approximate of 1000 inbred lines representing a wide range of maturities (early, intermediate and late), adaptation (tropical, subtropical and temperate), color (white, yellow, orange), quality (lysine content), and kernel characteristics (flint, dent) were screened in these nurseries. Traits such as early vigor, maturity, adaptation, plant and ear height, grain color, cob color, texture, disease
resistance (i.e. aflatoxin), and ear characteristics were recorded and ultimately used to classify and select the most promising germplasm for our program objectives.
Impacts
With the development of this corn germplasm we have contributed to the to the diversity of corn germplasm in the U.S. and to the improvement of corn hybrids for sustainable productivity, value-added profitability and food safety.
Publications
- F.J. Betran, Tom Isakeit, Gary Odvody. 2001. Aflatoxin resistance of maize germplasm in Texas A&M University. In 55th Annual Meeting of the Rio Grande Valley Horticulture Society, Weslaco, TX. January 23, 2001.
- F. J. Betran, Tom Isakeit, Gary Odvody, Kerry Mayfield. 2001. Maize Germplasm Evaluation for Aflatoxin Resistance in Texas. In proceedings of the Aflatoxin/Fumonisin Workshop 2001, October, 2001, Phoenix, AR.
- S. Bhatnagar, F. J. Betran, D. Transue. Response of Quality Protein Maize to Aflatoxin Contamination 2001. Maize Germplasm Evaluation for Aflatoxin Resistance in Texas. In proceedings of the Aflatoxin/Fumonisin Workshop 2001, October, 2001, Phoenix, AR.
- F. J. Betran and Tom Isakeit. Aflatoxin Contamination of Early, Intermediate, and Late maturing maize hybrids in Texas. In proceedings of the Aflatoxin/Fumonisin Workshop 2001, October, 2001, Phoenix, AR.
- J. Franco, J. Crossa, J.M. Ribaut, F.J. Betran, M.L. Warburton, and M. Khairallah. 2001. A method for combining molecular markers and phenotypic attributes for classifying plant genotypes. Theor Appl Genet (2001) 103:944-952.
- J.M. Ribaut, F.J. Betran, K. Dreher, K. Pixley, and David Hoisington. 2001. Marker-assisted selection in maize: strategies, examples and costs. In Plant & Animal Genome IX abstracts, San Diego, CA.
- L.L.Darrah, D.R. West, R.L. Lundquist, B.E. Hibbard, A. Schaafsma, E.A. Lee, S. Mbuvi, C.G. Poneleit, F.J. Betran, W. Xu, J.K. Pataky, L.D. Maddux, B. Gordon, R.W. Elmore, D. Stenburg, Z. W. Wicks III, P. Beauzay, P. Thomison, D.M. Jordan, K.E. Ziegler, R. Henry, J.A. Deutsch, J.F. Strissel, and D.B. Fischer. White food corn 2000 performance tests. Special Report 535. ARS-USDA.
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Progress 01/01/00 to 12/31/00
Outputs
During the 2000 season we have continued the evaluation, characterization and selection of corn germplasm with different origins and genetic backgrounds to develop inbred lines with superior grain quality, aflatoxin resistance, adaptation to Texas, and tolerance to abiotic stresses. We have conducted multilocation testing across the major corn production regions of Texas and evaluated germplasm under controlled drought stress and under artificial inoculation of the Aspergillus flavus, fungi responsible of aflatoxin production in corn. We have maintained our cooperation with national and international institutions. Approximately 700 experimental hybrids were tested across Texas to identify the most adapted germplasm to the local conditions. Different traits (yield, maturity, moisture, test weight, lodging, ear and plant height, cob and grain color, texture, disease resistance, etc.) were recorded. The 2000 season has been good with timely rainfall, low stress at
flowering time, and low incidence of aflatoxin. We will select the best material in these trials considering its overall performance, local adaptation, and quality. In these evaluations we have collaborated with other public programs and agencies, international centers, and private seed companies. Also, we have continued as a cooperator of The U.S. Germplasm Enhancement of Corn (GEM) project. Aflatoxin resistant candidate inbred lines and hybrids were tested under artificial inoculation in three Texas locations. We have identified white and yellow inbreds with consistent low AF content in hybrid combinations. The most promising inbreds for the Texas growing conditions are CML322, CML269, CML176 among the whites and CML326, Tx772, CML285 and Mp715 among the yellows. We will characterize further these genotypes, initiate the transfer of AF resistance to elite inbreds, and combine different types of aflatoxin resistance. Quality Protein Maize (QPM) hybrids were evaluated in Texas
environments. QPM in general had longer maturities, bigger tassels, higher ear placements, higher lodging, and lower grain yields than commercial checks. White QPM hybrids performed better in Texas than the yellow QPM hybrids. During 2000 we had two nurseries. One during the regular season (summer) at College Station and one off-season (winter) at Weslaco. Unfortunately a hailstorm before flowering severely damaged our summer nursery and trials at College Station. An approximate of 1000 inbred lines and 50 populations representing a wide range of maturities (early, intermediate and late), adaptation (tropical, subtropical and temperate), color (white, yellow, orange), quality (lysine content), and kernel characteristics (flint, dent) were screened in these nurseries. Traits such as early vigor, maturity, adaptation, plant and ear height, grain color, cob color, texture, disease resistance (aflatoxin, head smut), and ear characteristics were recorded and ultimately used to classify and
select the most promising germplasm for our program objectives.
Impacts
With the development of this corn germplasm we have contributed to the diversity of corn germplasm in the U.S. and to the improvement of corn hybrids for sustainable productivity, value-added profitability and food safety.
Publications
- Betran, F.J., Isakeit, T., and Odvody, G. 2000. Aflatoxin resistance of maize germplasm in Texas. In Agronomy Abstracts. Minneapolis, MN.
- Betran, F.J., Rooney, L., Fojt, F Pietsch, D. and Synatschk, L. 2000. Quality Protein Maize development in Texas. In Agronomy Abstracts. Minneapolis, MN.
- Bhatnagar, S., Betran, F.J., Transue, D., Cordova, H. and Srinivasan, G. 2000. Evaluation of QPM subtropical/tropical hybrids in Texas. In Agronomy Abstracts. Minneapolis, MN.
- L.L. Darrah, R.L. Lundquist, B.E. Hibbard, S. Mbuvi, C.G. Poneleit, D.R. West, F. J. Betran, W. Xu, J.K. Pataky, L.D. Maddux, B. Gordon, R.W. Elmore, D. Stenburg, Z. W. Wicks III, P. Beauzay, P.R. Thomison, D.M. Jordan, A. Schaafsma, E.A. Lee, K.E. Ziegler, X. Zhu, D. Fischer, R. Henry, J.A. Deutsch, and J.F. Strissel. 1999. White food maize 1999 performance tests. Special Report 528. ARS-USDA.
- F.J. Betran, T. Isakeit, G. Odvody. 2000. Maize resistance to aflatoxin in Texas. Aflatoxin Workshop. Tenaya Fish Camp, California.
- M. Willcox, G. Davis, G. Windham, Paul Williams, Hamed Abbas, and J. Betran. 2000. Confirmation of QTL regions for aflatoxin resistance by evaluating tails of the Va35 x Mp313E mapping population in multiple environments. Aflatoxin Workshop. Tenaya Fish Camp, California.
- P. Williams, G. Windham, M. Willcox, H. Abbas, J. Betran, D. White, S. Moore, R. Mascagni, K. Damann and N. Widstrom. 2000. Multilocation evaluation of single cross maize hybrids for aflatoxin contamination. Aflatoxin Workshop. Tenaya Fish Camp, California.
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Progress 01/01/99 to 12/31/99
Outputs
During the 1999 season we have continued the evaluation, characterization and selection of corn germplasm (inbred lines, populations or synthetics, and hybrids) with different origins and genetic backgrounds. We have conducted multilocation testing across the major corn production regions of Texas and evaluated germplasm under controlled drought stress and under artificial inoculation of the Aspergillus flavus, fungi responsible of aflatoxin production in corn. We have maintained our cooperation with national and international institutions. Approximately 3,200 experimental hybrids were tested across Texas to identify the most adapted germplasm to the local conditions. Different traits (yield, maturity, moisture, test weight, lodging, ear and plant height, cob and grain color, texture, disease resistance, etc.) were recorded. The 1999 season has been better than the 1998 season with timely rainfall, less stress at flowering time, and less incidence of aflatoxin. We
will select the best material in these trials considering its overall performance, local adaptation, and quality. In these evaluations we have collaborated with other public programs and agencies (Crop testing program, Corn breeding program at Lubbock, Pathology, Extension, County Agents, etc), international centers (CIMMYT), and private seed companies. Also, we have continued as a cooperator of The U.S. Germplasm Enhancement of Corn (GEM) project. Aflatoxin resistant candidate inbred lines and hybrids were tested under artificial inoculation in three Texas locations: Weslaco, Corpus Christi and College Station. We have identified genotypes showing resistance in our conditions (CML269, CML322, Tex 6, Mp313E among the whites, and A633, FR2128 among the yellows). We will characterize further these genotypes, initiate the transfer of AF resistance to elite inbreds, and combine different types of aflatoxin resistance. During 1999 we had two nurseries. One during the regular season
(summer) at College Station (3,000 plots) and one off-season (winter) at Florida (2,000 plots). An approximate of 1000 inbred lines and 50 populations representing a wide range of maturities (early, intermediate and late), adaptation (tropical, subtropical and temperate), color (white, yellow, orange), quality (Quality Protein Corn), and kernel characteristics (flint, dent) were screened in these nurseries. Traits such as early vigor, maturity, adaptation, plant and ear height, grain color, cob color, texture, disease resistance (aflatoxin, head smut), and ear characteristics were recorded and ultimately used to classify and select the most promising germplasm for our program objectives.
Impacts
With the development of this corn germplasm we expect to contribute to the to the diversity of corn germplasm in the U.S. and to the improvement of corn hybrids for sustainable productivity, value-added profitability and food safety.
Publications
- J.M. Ribaut and F.J. Betran. 1999. Single large-scale marker-assisted selection (SLS-MAS). Molecular Breeding, December 1999 issue: 1-11.
- F.J. Betran, A. Bockholt, Lloyd Rooney. Blue Corn. 1999. In (A.R. Hallauer, ed) Specialty Corns. CRC. Boca Raton, Florida, USA.
- Pietsch D., Synatschk, L., Betran, J., and Fojt III, F. 1999. Corn performance tests in Texas. Technical Report No. 99-25. Tx.. Agr. Exp. Sta. College Station, Texas, 80pp.
- Pietsch D., Rooney, L.W., Suhendro, E.L., Synatschk, L., Betran, J., and Fojt III, F. 1999. Texas food corn performance tests. Technical Report No. 99-26. Tx.. Agr. Exp. Sta. College Station, Texas, 37pp.
- L.L.Darrah, R.L. Lundquist, B.E. Hibbard, S. Mbuvi, C.G. Poneleit, D.R. West, R. Bernardo, J. Betran, J.K. Pataky, L.D. Maddux, B. Gordon, R.W. Elmore, D. Stenburg, K.E. Ziegler, Z. W. Wicks III, P. Thomison, A. Schaafsma, X. Zhu, D. Fischer, R. Henry, J.A. Deutsch, and D. Benson. 1998. White food corn 1998 performance tests. Special Report 518. ARS-USDA.
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Progress 01/01/98 to 12/31/98
Outputs
During the 1998 season we have evaluated and introduced maize germplasm (inbred lines, populations or synthetics, and hybrids) with different origins and genetic backgrounds. We have established a multilocation testing representing the wide range of environmental conditions across the major corn production regions of Texas as well as the evaluation of germplasm under controlled drought stress (different water regimes) and under artificial inoculation of the Aspergillus flavus, fungi responsible of aflatoxin production in maize. The Texas corn breeding program became a cooperator of The U.S. Germplasm Enhancement of Maize (GEM) project, a nation wide cooperative effort involving both private and public institutions that has the ultimate aim of improving and broadening the American corn germplasm. We have initiated collaboration with CIMMYT and Iowa State University in the search of new sources of stress resistance/tolerance and value added traits in maize. An
approximate of 600 inbred lines and 30 populations representing a wide range of maturities (early, intermediate and late), adaptation (tropical, subtropical and temperate), color (white, yellow, orange), and kernel characteristics (flint, dent) were evaluated in Texas. Traits such as early vigor, maturity, adaptation, plant and ear height, grain color, cob color, texture, disease resistance (aflatoxin, head smut), and ear characteristics were recorded and ultimately used to classify and select the most promising germplasm for our program objectives. Quality Protein Maize (QPM) inbreds from CIMMYT, South Africa and Texas were increased and crossed for further selection and testing during 1999. Hybrid trials of 650 hybrids (7200 experimental plots) were conducted across different locations in Texas (Weslaco, Corpus Christi, Castroville, College Station, Lubbock and Springlake). Grain yield, agronomic traits (maturity, moisture, lodging, ear and plant height, disease resistance) and
quality traits relevant for food corn (test weight, texture, pericarp removal, cob and grain color, density, hardness) were recorded according with the location and germplasm type. The season was difficult because the hot and dry weather during the summer. Those conditions affected our trial and nursery plots, which were affected by drought stress, charcoal rot and aflatoxin. A considerable variation in the response of the germplasm under evaluation to Texas environments and growing conditions was observed. Selection for drought tolerance was initiated by using different water regimes (full irrigated, pre-tassel and post-tassel stress) controlled by irrigation. Aflatoxin screening was established at Corpus Christi, TX by using artificial inoculation with Aspergillus flavus. We are selecting the best of this germplasm considering its overall performance, drought tolerance, disease resistance (with main focus in aflatoxin), and quality traits. A winter nursery to accelerate the
development of germplasm was established in Florida during the fall of 1998.
Impacts
(N/A)
Publications
- Edmeades, G.O., Ribaut, J.M., Banziger, M., Betran, F.J., and Beck, D.L.. 1998. Towards molecular breeding for mid-season drought tolerance in tropical maize. Plant and Cell Biology Abstracts. SEB Annual Meeting. Journal of experimental botany. Vol. 49.
- Pietsch D., Rooney, L.W., Suhendro, E.L., Synatschk, L., Betran, J., and Fojt III, F. 1998. Texas food corn performance tests. Technical Report No. 98-06. Tx.. Agr. Exp. Sta. College Station, Texas, 32pp.
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