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ARS Home » Southeast Area » Raleigh, North Carolina » Plant Science Research » Research » Research Project #434257

Research Project: Broadening the Genetic Base of U.S. Maize with Genes from Subtropical Genetic Resources

Location: Plant Science Research

Project Number: 6070-21000-031-00-D
Project Type: In-House Appropriated

Start Date: Mar 7, 2018
End Date: Mar 6, 2023

Objective:
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.