BREEDING DISEASE AND INSECT RESISTANT CORN INBREDS AND HYBRIDS

• Sponsoring Institution: National Institute of Food and Agriculture
• Project Status: COMPLETE
• Funding Source: HATCH
• Reporting Frequency: Annual
• Accession No.: 1007184
• Project Start Date: Oct 1, 2015
• Project End Date: Sep 30, 2019
• Program Code: [(N/A)]- (N/A)

Recipient Organization
CORNELL UNIVERSITY
(N/A)
ITHACA,NY 14853

Performing Department
Plant Breeding

Non Technical Summary
Field corn is the most important single crop grown in NY, planted in 2014 on 1.14 million acres and producing harvests worth about$612 million. Corn is a critical feed for the state's $3.5billion dairy industry and an important feedstock for biofuel. Recent years have seen increasing corn pest pressure (most notably northern leaf blight and gray leaf spot). This project focuses on corn breeding and field evaluation for improved pest resistance, which will boost corn production in sustainable ways and promote environmentally sound practices. Corn varieties that are resistant to diseases and insects minimize losses, reduce incentives for pesticide use, and improve profits from corn production systems. Resistance to these biological stresses will be increasingly important as our climate changes. With corn acreage increasing and climate change impacts being felt already, this work is critically important now. It merits public funding because private sector support for corn breeding is primarily focused on the large seed markets of the corn belt. Production systems and constraints in corn belt agroecologies are different from those that confront producers in New York, the northeast, and other areas beyond the central corn belt.For the major corn diseases (northern leaf blight, gray leaf spot, anthracnose leaf blight, and anthracnose stalk rot) and for European corn borer, new resistance sources are in the breeding pipeline in Cornell's corn breeding program. Still better resistance sources are needed for the future of agriculture. Continued development of existing and new resistance sources is part of the work proposed in this project. In addition, inheritance of resistance will be studied to determine how best to capitalize on current and future resistant sources in breeding efforts. Finally, there is a need to evaluate yield potential and agronomics on any new pest resistant sources developed, to ensure that pest resistance does not come at the expense of yield and agronomic quality (a trade-off that happens all too often). Classical plant breeding, screening, and selection methods will be used to achieve these goals. All breeding and testing will take place without seed treatment to ensure that we are selecting for strong early season vigor in cold wet soils and resistance to seedling emergence diseases. New sources of disease and insect resistance will be sought by screening corn varieties from other parts of the world and corn wild relatives that are likely to be resistant or reported to carry resistance. Classical genetic designs will be used to understand the inheritance of resistance in new sources identified. All new resistant sources developed through breeding will be evaluated in replicated hybrid yield trials in target management systems, both at experiment station sites and in farmers' fields. Results will be used to identify varieties that are genetically tailored to thrive in New York's agro-ecologies and local crop management systems, and maintain their target disease and/or insect resistance. Our work will result in new resistant corns with traits essential to future performance and productivity, genetic analysis of resistance to allow more efficient breeding, and varieties with improved yield potential and performance stability in sustainable corn management systems. The novel resistant corns developed through this project will help to enhance genetic diversity and thus stability in the U.S. corn germplasm base. Impacts will initially reach corn breeders and researchers, but will ultimately translate into improved commercial hybrids that provide growers with low-cost and environmentally-sound options for pest and crop management. The proposed research will contribute to sustainable agricultural systems in New York because of the importance of corn in the state.

Animal Health Component

50%

Research Effort Categories

Basic

10%

Applied

50%

Developmental

40%

Classification

Knowledge Area (KA)	Subject of Investigation (SOI)	Field of Science (FOS)	Percent
202	1510	1081	100%

Knowledge Area
202 - Plant Genetic Resources;

Subject Of Investigation
1510 - Corn;

Field Of Science
1081 - Breeding;

Keywords

corn breeding

disease resistance

european corn borer resistance

inheritance of resistance

northern leaf blight

gray leaf spot

anthracnose leaf blight and stalk rot

Goals / Objectives
1. Identify novel sources of resistance in corn to anthracnose stalk rot, European corn borer, northern leaf blight, and gray leaf spot and introduce them into New York-adapted inbreds and hybrids. 2. Investigate the genetics of novel pest resistant sources, including sources of resistance to multiple diseases.3. Test the yield potential, pest resistance, and performance stability of experimental hybrids produced from novel pest resistant parents bred at Cornell.

Project Methods
Classical breeding and screening methods will be used, complemented by marker-assisted selection as appropriate. All breeding and testing will take place without seed treatment to ensure that we are selecting for strong early season vigor in cold wet soils and resistance to seedling emergence diseases.Objective 1: Identify novel sources of resistance to anthracnose stalk rot, European corn borer, northern leaf blight, and gray leaf spot and introduce them into New York-adapted inbreds and hybrids.Novel sources of disease and insect resistance will be sought by screening exotic germplasm and wild relatives chosen for their reported or likely resistance to these or related pathogens and insects. Screening will be done with artificial inoculation/infestation to ensure uniform pest pressure, or in the case of GLS where reliable artificial inoculation techniques are lacking, disease hot spots will be used. Multiple year evaluation with comparison to our best resistant sources and to susceptible checks will be the basis for identification of promising new resistance sources. Modified backcrossing will be used to move these resistances into New York-adapted inbreds, with specifics of the breeding methods adjusted as more is learned about the inheritance patterns of the particular resistance source.Objective 2: Investigate the genetics of novel pest resistant sources, including sources of resistance to multiple diseasesDiallel, generation means, and molecular genetic approaches will be used to study the genetics of novel resistance sources. Results of a generation means analysis of gray leaf spot resistance source 22613 will be finalized and published. Screening of a BC3S2 recombinant inbred population derived from 22613 (resistant to multiple diseases) and Oh7B (highly susceptible to most diseases) will be used to investigate the genetics of multiple disease resistance in 22613. The 296 progenies comprising this mapping population will be screened for resistant to NLB, ALB, rust, and Stewart's wilt. Molecular genetic analysis for QTL underlying resistance to each disease individually will be used to identify loci that co-localize for one or more diseases. In addition, we will create a variable that represents multiple disease resistance score for each line and analyze the molecular basis of this trait.Given that ASR is costly and labor-intensive to evaluate, we will not aim to evaluate the 296-family mapping population for this disease. Rather, we will compare known ASR evaluation techniques (based on injecting spore suspension into the lowermost internode of each stalk shortly after flowering, and then splitting stalks open to rate the extent of disease at harvest) with potentially higher-throughput methods using imaging technology in an attempt to find a more cost-effective approach to screening.Objective 3: Test the yield potential, pest resistance, and performance stability of experimental hybrids produced from novel pest resistant parents bred at Cornell.Replicated evaluation of testcross hybrids in target management systems, both at experiment station sites and in farmers' fields, will be used to identify varieties that are genetically tailored to thrive in New York's agro-ecologies and with local crop management systems. All trials will be planted using 0.002 acre plots and two to three replications per location. Selection pressure in all breeding nurseries and trials will take advantage of conditions that occur in each growing season. For example, the 2013 and 2014 seasons led to high levels of both northern leaf blight and gray leaf spot in many locations around the state, and eyespot was prominent in 2014 as well. This allowed us to identify the most disease resistant progenies and hybrids in both nurseries and yield trials. Data will be collected in September on presence and intensity of any disease and insect damage at all yield trial locations. Yield, stalk and root lodging, and grain moisture at harvest will be measured to assess hybrid adaptation and yield potential in all trials.

Progress 10/01/15 to 09/30/19

Outputs
Target Audience:The target audiences for this project include corn breeders, corn seed companies, and both conventional and organic corn farmers. Changes/Problems: Nothing Reported What opportunities for training and professional development has the project provided?One graduate student is finishing his M.S. thesis on a genetic analysis of anthracnose stalk rot resistance, and onePh.D. student completed his research on multiple disease resistance mapping.Graduate and undergraduate lectures in three Cornell courses shared information about corn breeding related to disease and insect resistance. A lecture in the Gender-responsive Researchers Equipped for Agricultural Transformation (GREAT) Program educated plant breeders and social scientists from Sub-Saharan Africa about objectives and challenges in corn breeding. How have the results been disseminated to communities of interest?Information about Cornell's corn breeding program and results from this research project were shared at the Aurora Organic Field Day on 16 July 2019 and with Cornell plant breeding graduate students at a field tour on 17 September 2019. Results also were highlighted in a display at New York's Empire Farm Days, a three-day farm show in August 2019 that draws thousands of visitors, and with Cornell students, faculty, and staff at the Cornell CALS Day on 26 April 2019. What do you plan to do during the next reporting period to accomplish the goals? Nothing Reported

Impacts
What was accomplished under these goals? For corn diseases of major importance in NY and the northeast (northern leaf blight, gray leaf spot, and anthracnose stalk rot) and for European corn borer, new resistance sources are in the breeding pipeline in Cornell's corn breeding program. Still better resistance sources are needed for the future of agriculture. Continued development of existing and new resistance sources and evaluation of their yield potential and agronomics are the primary activities of this project. This work aims to ensure that pest resistance is available to build into new corn varieties, and that it does not come at the expense of yield and agronomic quality (a trade-off that happens all too often). We also have studied the genetics of pest resistance in the new genetic materials bred through our work, to facilitate their efficient use in commercial hybrid production and in future breeding efforts. Our work helps to ensure the future availability of pest resistant corn hybrids, thus contributing to future performance and productivity of sustainable corn management systems. The novel resistant corns developed through this project will help to enhance genetic diversity and thus stability in the U.S. corn germplasm base. Impacts will initially reach corn breeders and researchers, but ultimately will translate into improved commercial hybrids that provide growers with environmentally-sound options for pest and crop management. For objective 1 (identify novel sources of resistance to anthracnose stalk rot, European corn borer, northern leaf blight, and gray leaf spot and introduce them into New York adapted inbreds and hybrids), we developed new inbreds and breeding lines for all four target pests. For anthracnose stalk rot, we will choose the best of four finished inbreds to release as a new resistance source. One new European corn borer resistant inbred is ready for release as a germplasm source and fourteen additional new inbreds are undergoing final evaluation to choose release candidates. We will also choose release candidates based on completed final evaluations of five gray leaf spot resistant inbreds.A germplasm release manuscript is in preparation for two multiple disease resistant inbreds, which show strong resistance to northern leaf blight and gray leaf spot, and good resistance to rust, Stewart's wilt, southern leaf blight, and anthracnose stalk rot. For objective 2 (investigate the genetics of novel pest resistant sources, including sources of resistance to multiple diseases), a Ph.D. dissertation was completed and publications are in preparation from study of a 297-family BC3S3 mapping population developed at Cornell. The population was screened for northern leaf blight, gray leaf spot, and Stewart's wilt to identify regions of the genome associated with both individual and multiple disease resistance.The analysis revealed 16 quantitative trait loci (QTL) associated with northern leaf blight resistance, 17 QTL with gray leaf spot resistance, and 16 QTL with Stewart's wilt resistance. No QTL were colocalized for all three diseases, but three QTL were shared for northern leaf blight and gray leaf spot resistance, and one QTL was shared for gray leaf spot and Stewart's wilt resistance. Theligueless1gene emerged from the mapping study as associated with gray leaf spot and Stewart's wilt resistance and from the RNA differential expression study as associated with northern leaf blight resistance - a particularly interesting result implicating this gene in multiple disease resistance expression.An M.S. thesis is nearing completion for adiallel study of inheritance in four Cornell-developed anthracnose stalk rot resistant inbreds. Results indicated that one of these four, derived from a Brazilian stalk rot resistant source recombined with a locally-adapted genetic materials, has highly significant general combining ability for anthracnose stalk rot resistance. This result demonstrates that the new inbred will convey strongly improved anthracnose stalk rot resistance to its hybrid combinations. For objective 3 (test the yield potential, pest resistance, and performance stability of experimental hybrids produced from novel pest resistant parents bred at Cornell), 76 new hybrids and varieties were evaluated for yield and adaptation to New York growing conditions, including evaluations on conventional dairy farms, conventional cash grain farms, and organic farms. These include primarily pest resistant inbreds developed through this project, but also some inbreds developed strictly for improved local adaptation and yield potential as well as commercial checks. This evaluation helps to ensure that the products of our breeding efforts have the requisite performance to be competitive in light of existing varieties in the marketplace.

Publications

• Type: Journal Articles Status: Accepted Year Published: 2020 Citation: Falcon, Celeste M., Shawn M. Kaeppler, Edgar P. Spalding, Nathan D. Miller, Nicholas Haase, Naser AlKhalifah, Martin Bohn, Edward S. Buckler, Darwin A. Campbell, Ignacio Ciampitti, Lisa Coffey, Jode Edwards, David Ertl, Sherry Flint-Garcia, Michael A. Gore, Christopher Graham, Candice N. Hirsch, James B. Holland, Diego Jarqu�n, Joseph Knoll, Nick Lauter, Carolyn J. Lawrence-Dill, Elizabeth C. Lee, Aaron Lorenz, Jonathan P. Lynch, Seth C. Murray, Rebecca Nelson, Cinta M. Romay, Torbert Rocheford, Patrick S. Schnable, Brian Scully, Margaret Smith, Nathan Springer, Mitch Tuinstra, Renee Walton, Teclemariam Weldekidan, Randall J. Wisser, Wenwei Xu, and Natalia de Leon. 2019. Relative Utility of Agronomic, Phenological, and Morphological Traits for Assessing Genotype-by- Environment Interaction in Maize Inbreds. In press. Crop Science doi: 10.1002/csc2.220035
• Type: Books Status: Published Year Published: 2020 Citation: Kass, L.B., E.H. Coe, M.N. Cook, M.E. Smith, J.L. Singer (Eds.) 2019. Founding of the Maize Genetics Cooperation News Letter at Cornell University: A 90th Anniversary Tribute. (Foreword by E.S. Buckler) [e-book] Internet-First University Press, Ithaca, New York. https://ecommons.cornell.edu/handle/1813/66550
• Type: Theses/Dissertations Status: Published Year Published: 2019 Citation: Palanichamy, D. 2019. Genetics of Multiple Disease Resistance in Maize Inbred NY22613 and Science Communication of Quantitative Genetics. Ph.D. Dissertation, Cornell University. 140 pp.

Progress 10/01/17 to 09/30/18

Outputs
Target Audience:The target audiences for this project include corn breeders, corn seed companies, and both conventional and organic corn farmers. Changes/Problems: Nothing Reported What opportunities for training and professional development has the project provided?One graduate student is conducting a genetic analysis of anthracnose stalk rot resistance for his M.S. thesis, and onePh.D. student is doing his research on multiple disease resistance mapping.Graduate and undergraduate lectures in three courses shared information about corn breeding related to disease and insect resistance. Additionally, a tour of our corn breeding nursery was provided to 30 undergraduate summer program students from China, who are aiming to carry out graduate study in plant sciences. How have the results been disseminated to communities of interest?Information about Cornell's corn breeding program and results from this research project were shared at the Musgrave Farm Field Day on 12 July 2018 and with Cornell plant breeding graduate students at a field tour on 11 September 2018. Results also were highlighted in a display at New York's Empire Farm Days, a three-day farm show in August 2018 that draws thousands of visitors. What do you plan to do during the next reporting period to accomplish the goals?In 2018-2019, we will continue screening new materials obtained as sources of pest resistance to identify effective genetic variation in corn for resistance (objective 1).We also will advance the breeding progenies that are in the pipeline for both disease and insect resistance to continue development of new resistant corn inbreds. We will publish data from our multiple disease resistant mapping population and from our anthracnose stalk rot resistance diallel study, to more accurately identify regions of the genome associated with individual and multiple disease resistances (objective 2). Variety testing in farmers' fields, both conventional and organic, will be carried out to ensure that new resistance sources being developed have the adaptation and yield potential that will allow them ultimately to benefit New York corn farmers (objective 3).

Impacts
What was accomplished under these goals? For the major corn diseases (northern leaf blight, gray leaf spot, and anthracnose stalk rot) and for European corn borer, new resistance sources are in the breeding pipeline in Cornell's corn breeding program. Still better resistance sources are needed for the future of agriculture. Continued development of existing and new resistance sources is part of the work proposed in this project.In addition, yield potential and agronomics must be evaluated on any new pest resistant sources developed, to ensure that pest resistance does not come at the expense of yield and agronomic quality (a trade-off that happens all too often). Finally, we will study the genetics of pest resistance in these sources to facilitate their efficient use in commercial hybrid production and in future breeding efforts. Our work will result in new resistant corn inbreds with traits essential to future performance and productivity, genetic analysis of resistance to allow more efficient breeding, and potential to produce commercial varieties with improved yield and performance stability in sustainable corn management systems. The novel resistant corns developed through this project will help to enhance genetic diversity and thus stability in the U.S. corn germplasm base. Impacts will initially reach corn breeders and researchers, but will ultimately translate into improved commercial hybrids that provide growers with environmentally-sound options for pest and crop management. For objective 1 (identify novel sources of resistance to anthracnose stalk rot, European corn borer, northern leaf blight, and gray leaf spot and introduce them into New York adapted inbreds and hybrids), we have developed new inbreds and breeding lines for all four target pests. For anthracnose stalk rot, we have 40 inbreds ready for final evaluations and another 129 breeding lines under development and resistance screening. One new European corn borer resistant inbred is ready for release as a germplasm source.Additionally, we have 34 new resistant inbreds and another 32 breeding families undergoing selection for European corn borer resistance. Selection is on-going for gray leaf spot resistance in 109 breeding lines and seven resistant inbreds are ready for pre-release disease and yield screening. For objective 2 (investigate the genetics of novel pest resistant sources, including sources of resistance to multiple diseases), final analysis and summary of results is underway for a 297-family BC3S3 mapping population developed at Cornell that was screened to identify regions of the genome associated with both individual and multiple disease resistance. The mapping population underwent phenotypic evaluations for northern leaf blight, gray leaf spot, and Stewart's wilt in replicated trials during two growing seasons. The Cornell-developed multiple disease resistant parent of this population and a close sister line to it are both ready for release. These lines carry resistance to gray leaf spot, northern leaf blight, southern leaf blight, and anthracnose leaf blight and moderate resistance to anthracnose stalk rot and Stewart's bacterial wilt. Results are being analyzed and interpreted for a diallel study elucidating the genetics of resistance in four Cornell-developed anthranose stalk rot resistant inbreds. For objective 3 (test the yield potential, pest resistance, and performance stability of experimental hybrids produced from novel pest resistant parents bred at Cornell), 76 new hybrids and varieties were evaluated for yield and adaptation to New York growing conditions, including evaluations on conventional dairy farms, conventional cash grain farms, and organic farms. Additionally, 16 experimental inbreds developed for resistance to anthracnose stalk rot were crossed to testers and evaluated in on-farm replicated yield trials to determine their adaptation and yield potential in this geography. Good yield potential is a critical prerequisite to release of new disease and insect resistant inbreds from our program.

Publications

• Type: Journal Articles Status: Published Year Published: 2018 Citation: AlKhalifah, N., D.A. Campbell, C.M. Falcon, J.M. Gardiner, N.D. Miller, M.C. Romay, R. Walls, R. Walton, C-T. Yeh, M. Bohn, J. Bubert, E.S. Buckler, I. Cimapitti, S. Flint-Garcia, M.A. Gore, C. Graham, C. Hirsch, J.B. Holland, D. Hooker, S. Kaeppler, J. Knoll, N. Lauter, E.C. Lee, A. Lorenz, J.P. Lynch, S.P. Moose, S.C. Murray, R. Nelson, T. Rocheford, O. Rodriguez, J.C. Schnable, B. Scully, M. Smith, N. Springer, P. Thomison, M. Tuinstrra, R.J. Wisser, W. Zu, D. Ertl, P.S. Schnable, N. De Leon,E. P. Spalding, J. Edwards, C.J. Lawrence-Dill. 2018. Maize genomes to fields: 2014 and 2015 field season genotype, phenotype, environment, and inbred ear image datasets. BMC Research Notes. https://doi.org/10.1186/s13104-018-3508-1
• Type: Journal Articles Status: Published Year Published: 2018 Citation: Emmett, B.D., D.H. Buckley, M.E. Smith, and L.E. Drinkwater. 2018. Eighty years of maize breeding alters plant nitrogen acquisition but not rhizosphere bacterial community composition. Plant Soil. https://doi.org/10.1007/s11104-018-3744-0
• Type: Journal Articles Status: Published Year Published: 2017 Citation: Gage, J., D. Jarquin, M. Romay, A. Lorenz, E. Buckler, S. Kaeppler, N. Alkhalifah, M. Bohn, D. Campbell, J. Edwards, D. Ertl, S. Flint-Garcia, J. Gardiner, B. Good, C. Hirsch, J. Holland, D. Hooker, J. Knoll, J. Kolkman, G. Kruger, N. Lauter, C. Lawrence-Dill, E. Lee, J. Lynch, S. Murray, R. Nelson, J. Petzoldt, T. Rocheford, J. Schnable, P. Schnable, B. Scully, M. Smith, N. Springer, S. Srinivasan, R. Walton, T. Wekdekidan, R. Wisser, W. Zu, J. Yu, and N. de Leon. 2017. The effect of artificial selection on phenotypic plasticity in maize. Nature Communications 8:1348.
• Type: Journal Articles Status: Published Year Published: 2017 Citation: Huffman, R.D., C.A. Abel, L.M. Pollak, W. Goldstein, R.C. Pratt, M.E. Smith, et al. 2017. Maize Cultivar Performance under Diverse Organic Production Systems. Crop Sci. doi:10.2135/cropsci2017.06.0364.

Progress 10/01/16 to 09/30/17

Outputs
Target Audience:The target audiences for this project include corn breeders, corn seed companies, and both conventional and organic corn farmers. Changes/Problems: Nothing Reported What opportunities for training and professional development has the project provided?Graduate and undergraduate lectures in four courses shared information about corn breeding related to pest and stress tolerance. One graduate student is conducting a genetic analysis of anthracnose stalk rot resistance for his M.S. thesis, and one Ph.D. student is doing his research on multiple disease resistance mapping. How have the results been disseminated to communities of interest?A webinar presented in September 2017 as part of the eOrganic series informed attendees about different types of corn varieties, focusing on the nature, benefits, and weaknesses of each. Information about Cornell's corn breeding program and results from this research project were shared at the Musgrave Farm Field Day in July 2017 and with Cornell plant breeding graduate students at a field tour in September 2017. Results also were highlighted in a display at New York's Empire Farm Days, a three-day farm show in August 2017 that draws thousands of visitors. Finally, a display at Agstravaganza, an agriculture-focused event for the local Ithaca NY community, highlighted the benefits plant breeding provides to our food and agriculture system. What do you plan to do during the next reporting period to accomplish the goals?In 2017-2018, we will continue screening new materials obtained as sources of pest resistance to identify effective genetic variation in corn for resistance (objective 1). We also will advance the breeding progenies that are in the pipeline for both disease and insect resistance to continue development of new resistant corn inbreds. We will analyze and interpret data from our multiple disease resistant mapping population and from our anthracnose stalk rot resistance diallel study, to more accurately identify regions of the genome associated with individual and multiple disease resistances (objective 2). Variety testing in farmers' fields, both conventional and organic, will be carried out to ensure that new resistance sources being developed have the adaptation and yield potential that will allow them ultimately to benefit New York corn farmers (objective 3).

Impacts
What was accomplished under these goals? For the major corn diseases (northern leaf blight, gray leaf spot, and anthracnose stalk rot) and for European corn borer, new resistance sources are in the breeding pipeline in Cornell's corn breeding program. Still better resistance sources are needed for the future of agriculture. Continued development of existing and new resistance sources is part of the work proposed in this project. In addition, inheritance of resistance will be studied to determine how best to capitalize on current and future resistant sources in breeding efforts. Finally, there is a need to evaluate yield potential and agronomics on any new pest resistant sources developed, to ensure that pest resistance does not come at the expense of yield and agronomic quality (a trade-off that happens all too often). Our work will result in new resistant corns with traits essential to future performance and productivity, genetic analysis of resistance to allow more efficient breeding, and varieties with improved yield potential and performance stability in sustainable corn management systems. The novel resistant corns developed through this project will help to enhance genetic diversity and thus stability in the U.S. corn germplasm base. Impacts will initially reach corn breeders and researchers, but will ultimately translate into improved commercial hybrids that provide growers with environmentally-sound options for pest and crop management. For objective 1 (identify novel sources of resistance to anthracnose stalk rot, European corn borer, northern leaf blight, and gray leaf spot and introduce them into New York adapted inbreds and hybrids), we have developed new inbreds and breeding lines for all four target pests. For anthracnose stalk rot, we have 12 inbreds ready for final evaluations and another 71 breeding lines under development and resistance screening. Two new European corn borer resistant inbreds and one resistant population are ready for release as new germplasm sources. Additionally, we have five new resistant inbred and another 138 breeding families undergoing selection for European corn borer resistance. Selection is on-going for gray leaf spot resistance in 191 breeding lines and four resistant inbreds are ready for pre-release disease and yield screening. For objective 2 (investigate the genetics of novel pest resistant sources, including sources of resistance to multiple diseases), a 297-family BC3S3 mapping population developed at Cornell was screened to identify regions of the genome associated with both individual and multiple disease resistance in corn. The mapping population has been genotyped and the phenotypic evaluations for northern leaf blight, gray leaf spot, and Stewart's wilt have been done in replicated trials during two growing seasons. The Cornell-developed multiple disease resistant parent of this population and a close sister line to it are both ready for release. These lines carry resistance to gray leaf spot, northern leaf blight, southern leaf blight, and anthracnose leaf blight and moderate resistance to anthracnose stalk rot and Stewart's bacterial wilt. A diallel study with eight inbreds has been conducted to elucidate the genetics of resistance in the four Cornell-developed stalk rot resistant inbreds included in the study. For objective 3 (test the yield potential, pest resistance, and performance stability of experimental hybrids produced from novel pest resistant parents bred at Cornell), 86 new hybrids and varieties were evaluated for yield and adaptation to New York growing conditions, including evaluations on conventional dairy farms, conventional cash grain farms, and organic farms. Additionally, five experimental inbreds developed for resistance to European corn borer were crossed to testers and evaluated in on-farm replicated yield trials to determine their adaptation and yield potential in this geography. Good yield potential is a critical prerequisite to release of new disease and insect resistant inbreds from our program.

Publications

• Type: Conference Papers and Presentations Status: Published Year Published: 2017 Citation: Smith, M.E. 2017. Sustaining public plant breeding: What are the funding problems? Keynote, p. 20-24. In: W.F. Tracy, J.C. Dawson, V.M. Moore, and J. Fisch (eds.), Intellectual Property Rights for Public Plant Breeding Summit, Raleigh NC, 13-15 August 2016. University of Wisconsin-Madison.
• Type: Conference Papers and Presentations Status: Published Year Published: 2017 Citation: Lawton, A.B., J.R. Lawrence, M.E. Smith, W.S. Burhans, M.E. Van Amburgh, and T.R. Overton. 2017. The use of the Cornell Net Carbohydrate and Protein System in corn silage hybrid testing programs. Abstract T120. J. Dairy Sci. 100, Suppl. 2:268-269.
• Type: Conference Papers and Presentations Status: Published Year Published: 2017 Citation: Smith, M.E. 2017. GMOs: Food supply saviour or the devil in disguise? Proceedings 2017 Western Canadian Dairy Seminar. March 7-10, 2017. Red Deer, Alberta, Canada. WCDS Advances in Dairy Technology 29:19-34.
• Type: Conference Papers and Presentations Status: Published Year Published: 2017 Citation: Smith, M.E. 2017. Genetically engineered crops: Top-notch designer genes or the gene(ie) that got out of the bottle? pp. 8-15. In: 2017 Winter Crop Meeting Proceedings, Cornell Cooperative Extension South Central New York Dairy & Field Crops Team. January 20, 2017. Ithaca NY.
• Type: Conference Papers and Presentations Status: Published Year Published: 2016 Citation: Lawrence, J., A. Lawton, M. Smith, M. Van Ambrugh, T. Overton, S. Norman, K. Payne, and D. Fisher. 2016. New York corn hybrid silage trials 2016. pp. 8-10. In: J. Lawrence and T.R. Overton (eds.) Proceedings 2016 Feed Dealers Seminars. Animal Science Publication Series No. 246. Cornell University, Ithaca NY.

Progress 10/01/15 to 09/30/16

Outputs
Target Audience:The target audiences for this project include corn breeders, corn seed companies, and both conventional and organic corn farmers. Changes/Problems: Nothing Reported What opportunities for training and professional development has the project provided?Graduate and undergraduate course lectures shared information about corn breeding related to pest and stress tolerance. Seven lectures in different on-campus courses addressed this topic. One graduate student is carrying out a Ph.D. research project on multiple disease resistance mapping. How have the results been disseminated to communities of interest?Information about Cornell's corn breeding program and results from this research project were shared at Certified Crop Advisor training in November 2015 and with Cornell plant breeding graduate students at a field tour in September 2016. Results also were highlighted in a display at New York's Empire Farm Days, a three-day farm show in August 2016 that draws thousands of visitors. What do you plan to do during the next reporting period to accomplish the goals?In 2016-2017, we will continue screening new materials obtained as sources of pest resistance to identify effective genetic variation in corn for resistance (objective 1). We also will advance the breeding progenies that are in the pipeline for both disease and insect resistance to continue development of new resistant corn inbreds. We will carry out a second season of disease resistance screening in our multiple disease resistant mapping population to more accurately identify regions of the genome associated with individual and multiple disease resistance (objective 2). Variety testing in farmers' fields, both conventional and organic, will be carried out to ensure that new resistance sources being developed have the adaptation and yield potential that will allow them ultimately to benefit New York corn farmers (objective 3).

Impacts
What was accomplished under these goals? Field corn is the most important single crop grown in NY, planted on 1.13 million acres and producing harvests worth about $946 million over the period from 2010 to 2014. Corn is a critical feed for the state's $2.8 billion dairy industry and an important feedstock for biofuel. Recent years have seen increasing corn pest pressure (most notably northern leaf blight and gray leaf spot). This project focuses on corn breeding and field evaluation for improved pest resistance, which will boost corn production in sustainable ways and promote environmentally sound practices. Corn varieties that are resistant to diseases and insects minimize losses, reduce incentives for pesticide use, and improve profits from corn production systems. Resistance to these biological stresses will be increasingly important as our climate changes. For the major corn diseases (northern leaf blight, gray leaf spot, anthracnose leaf blight, and anthracnose stalk rot) and for European corn borer, new resistance sources are in the breeding pipeline in Cornell's corn breeding program. Still better resistance sources are needed for the future of agriculture. Continued development of existing and new resistance sources is part of the work proposed in this project. In addition, inheritance of resistance will be studied to determine how best to capitalize on current and future resistant sources in breeding efforts. Finally, there is a need to evaluate yield potential and agronomics on any new pest resistant sources developed, to ensure that pest resistance does not come at the expense of yield and agronomic quality (a trade-off that happens all too often). Our work will result in new resistant corns with traits essential to future performance and productivity, genetic analysis of resistance to allow more efficient breeding, and varieties with improved yield potential and performance stability in sustainable corn management systems. The novel resistant corns developed through this project will help to enhance genetic diversity and thus stability in the U.S. corn germplasm base. Impacts will initially reach corn breeders and researchers, but will ultimately translate into improved commercial hybrids that provide growers with low-cost and environmentally-sound options for pest and crop management. For objective 1 (identify novel sources of resistance to anthracnose stalk rot, European corn borer, northern leaf blight, and gray leaf spot and introduce them into New York adapted inbreds and hybrids), we have evaluated commercial testers to identify those most resistant to northern leaf blight. For gray leaf spot, experimental inbreds were evaluated to choose release candidates, new inbreds were testcrossed for such evaluations, and numerous breeding progenies were advanced. Anthracnose stalk rot resistant experimental inbreds were evaluated for resistance to choose candidates for yield testing, and many breeding progenies were inoculated, screened, selected, and advanced through further self pollinations. Two new European corn borer resistant inbreds and one resistant population are ready for release as new germplasm sources. New experimental corn borer resistant inbreds are undergoing final screening and selection, and various breeding progenies are being infested, screened, and selected for advancement. For objective 2 (investigate the genetics of novel pest resistant sources, including sources of resistance to multiple diseases), a BC3S3 mapping population of over 300 families developed at Cornell was screened to identify regions of the genome associated with both individual and multiple disease resistance in corn. The mapping population has been genotyped and the phenotypic evaluations for northern leaf blight, gray leaf spot, and Stewart's wilt were completed. Additionally, the Cornell-developed multiple disease resistant parent of this population is ready for release. It carries resistance to gray leaf spot, northern leaf blight, southern leaf blight, and anthracnose leaf blight and moderate resistance to anthracnose stalk rot and Stewart's bacterial wilt. For objective 3 (test the yield potential, pest resistance, and performance stability of experimental hybrids produced from novel pest resistant parents bred at Cornell), over 60 new hybrids and varieties were evaluated for yield and adaptation to New York growing conditions, including evaluations on conventional dairy farms, conventional cash grain farms, and organic farms. Additionally, experimental inbreds developed for resistance to gray leaf spot, anthracnose stalk rot, and European corn borer were crossed to testers and evaluated in on-farm replicated yield trials to determine their adaptation and yield potential in this geography. Good yield potential is a critical prerequisite to release of new disease and insect resistant inbreds from our program.

Publications

• Type: Journal Articles Status: Published Year Published: 2015 Citation: Smith, M.E., L. Ericson, S.A. Norman, and N. OLeary. 2015. Registration of NY195, NY212, NY215, and NY266 anthracnose stalk rot resistant inbred lines of maize. Journal of Plant Registrations 9:393-397.
• Type: Conference Papers and Presentations Status: Published Year Published: 2016 Citation: Smith, M.E. 2016. GMOs: Food supply savior or the devil in disguise? Proceedings 2016 Western Canadian Dairy Seminar. March 8-11, 2016. Red Deer, Alberta, Canada.
• Type: Conference Papers and Presentations Status: Published Year Published: 2016 Citation: Smith, M.E. 2016. What are GMO crops and how do we talk about them? pp. 21-38. Proceedings Corn Congress at Miner Institute. 4 February 2016. Chazy NY.