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ARS Home » Southeast Area » Raleigh, North Carolina » Plant Science Research » Research » Research Project #436890

Research Project: Adaptational Genomic Selection in Maize

Location: Plant Science Research

Project Number: 6070-21220-016-07-S
Project Type: Non-Assistance Cooperative Agreement

Start Date: May 1, 2019
End Date: Jan 14, 2021

Objective:
Develop and test a genomic selection pipeline for phenologically adapting U.S.-exotic maize to temperate U.S. environments. Cooperator will test the idea of a new artificial selection strategy for adapting maize populations to U.S. environments in which they are poorly adapted in terms of flowering time. This involves the production of new germplasm and data resources and the application of statistical modeling techniques to construct environment-specific prediction models that enable the selection of plants outside of the environments to which they are being adapted.

Approach:
This project uses maize as the research organism and leverages populations of a tropical synthetic (TropicS) partially adapted to DE and in NC by multiple generations of phenotypic selected for early flowering time (TropicS is still phenologically maladapted to these U.S. environments). A three-staged procedure will be used test the effectiveness of genomic selection for further adaptation of TropicS. In Stage 1, phenotypic mass selection for flowering time will be used to advance second generation DE- and NC-population lineages in their respective environments. At the same time, environment-specific prediction models for flowering time will be generated from two distinct training sets evaluated in field trials at each location: one training set will comprise non-replicated individual plants within the current generation under selection (INDI-model) and the other training set will comprise replicated inbred lines extracted from a generation prior to the one under selection (LINE-model). In Stage 2, the four separate prediction models (DE-INDI; DE-LINE; NC-INDI; NC-LINE) will be used to apply genomic selection to the third generation in an off-season winter nursery. DE models will be applied to the DE lineage and NC models will be applied to the NC lineage. In addition, randomly mated populations will be produced as experimental control populations. In Stage 3, all generations (G0-G3) from both environment-specific population lineages will be evaluated in both environments in a randomized complete block design with six replications. Data analysis will be performed to evaluate the response to phenotypic and genomic selection. A customized genotyping by sequencing (GBS) protocol for heterozygous plants will be used as the marker technology for genomic prediction and selection.