Location: Plant Science Research
2018 Annual Report
Objectives
Objective 1. Manage and coordinate the Southeastern component of a multi-year, multi-site, cooperative program of maize genetic resource evaluation, genetic enhancement, inbred line development, and information sharing which will broaden the genetic base for U.S. maize.
Objective 2. Evaluate temperate, subtropical, and tropical maize genetic resources for adaptation, yield, resistance to ear, stalk, and foliar diseases, tolerance to environmental extremes, and selected value-added, product quality traits. Record and disseminate evaluation data via the GEM database, GEM website, GRIN-Global, and other data sources.
Objective 3. Breed and release maize populations and inbred lines with primarily 50% unadapted/50% temperate pedigrees which contribute to U.S. maize more diverse genetic resistance to diseases, tolerance to environmental extremes, higher yield, unique product qualities, other valuable new traits, or which enable maize trait analysis and allelic diversity research.
Sub-objective 3A. Breed and release genetically-enhanced maize lines, derived from unadapted sub-tropical and tropical maize germplasm, that can contribute diverse and valuable new traits to commercial and public breeding programs.
Sub-objective 3B. Develop and release a novel set of “adapted” maize races resulting from the allelic diversity (AD) program as tools for gene discovery and genomic research.
Approach
Exotic maize genetic resources with agronomic potential for developing new breeding populations will be selected in cooperation with the Ames GEM (Germplasm Enhancement of Maize) coordinator and the GEM Technical Steering Group. Private company cooperators will make the initial crosses between commercial and exotic stocks, and each cooperator has agreed to conduct a specific set of evaluations (e.g. yield trials, abiotic or biotic stress, or breeding cross evaluations) in addition to the evaluations conducted in North Carolina by the Raleigh GEM coordinator. New exotic germplasm sources will be evaluated in testcrosses and then crossed to either proprietary inbreds or formerly proprietary (ex-PVP) inbreds to develop new breeding crosses for further evaluation. These breeding crosses will then be self-pollinated for two generations in abiotic and biotic nurseries to enhance selection of the most promising genotypes, which will subsequently be testcrossed and evaluated in yield and disease trials. In addition, less agronomically promising sources of exotic germplasm will be backcrossed to elite temperate inbred lines and inbred to create a set of 25% exotic/75% temperate lines that can be used for allele mining and gene discovery.
Progress Report
This project was initiated during FY2018. Overall, 10,300 yield plots were coordinated from Raleigh, North Carolina with about 4700 planted in North Carolina and the rest planted by six cooperators at various locations throughout the Southeast and Midwest. Five hundred and seventy-four Germplasm Enhancement of Maize (GEM) entries were evaluated in first-year trials and twenty-nine entries were evaluated in second-year trials. Disease evaluation continues in 2018 for Gray Leaf Spot (GLS), where advanced materials were evaluated at three locations in North Carolina (Laurel Springs, Salisbury, and Waynesville). Approximately 1200 GEM nursery rows and over 1000 isolation rows were planted in summer 2018 at Clayton, North Carolina, with an additional 250 rows of isolation planted by MBS, a GEM cooperator based in Story City, Iowa. Nursery work involved about forty different GEM breeding crosses, while over 500 new breeding crosses were observed for agronomic traits of interest. Most of the breeding crosses were produced by the program in Raleigh, North Carolina but approximately 25% of the crosses were supplied to the Raleigh program by the program in Ames, Iowa. Only 50 nursery rows in Clayton, North Carolina were devoted to the allelic diversity project, a significant drop from recent years that is in line with the near completion of the responsibilities of the Raleigh, North Carolina program to that project.
Accomplishments
