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United States Department of Agriculture

Agricultural Research Service

Research Project: Germplasm Enhancement and Genetic Improvement of Cotton Title: Genetic analysis without replications: Model evaluation and application in spring wheat

Authors
item Wu, Jixiang -
item Bondalapati, Krishna -
item Glover, Karl -
item Berzonsky, William -
item Jenkins, Johnie
item McCarty, Jack

Submitted to: Euphytica
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: November 11, 2012
Publication Date: February 1, 2013
Repository URL: http://handle.nal.usda.gov/10113/56065
Citation: Wu, J., Bondalapati, K., Glover, K., Berzonsky, W., Jenkins, J.N., McCarty, J.C. 2013. Genetic analysis without replications: model evaluation and application in spring wheat. Euphytica. 190:447-458.

Interpretive Summary: Data collected from plant breeding and genetic studies may not be replicated in field even though field variation is always present. In this study, we addressed this problem using spring wheat data collected from two locations. There were no intra-location replications and an extended additive-dominance genetic model was used to account for field variation. The data was numerically evaluated from a simulation and variance components were estimated. Three agronomic traits from the spring wheat data set were analyzed as a demonstration. Results illustrated that these data could be effectively analyzed using an extended additive-dominance model. Actual data analysis revealed that all analyzed traits were significantly influenced by systematic field variation. Additive effects were significant for all traits and dominance effects were significant for plant height and time-to-flowering. Genetic effects were predicted and used to demonstrate that most spring wheat lines developed by the South Dakota State University breeding program exhibited good general combining ability effects for yield improvement. Thus, this study provides a general framework to appropriately analyze data in situations where field crop data are collected from non-replicated designs.

Technical Abstract: Genetic data collected from plant breeding and genetic studies may not be replicated in field designs even though field variation is present. In this study, we addressed this problem using spring wheat (Triticum eastivum L.) trial data collected from two locations. There were no intra-location replications and an extended additive-dominance model was used to account for field variation. We numerically evaluated the data from a simulation and estimated the variance components. As a demonstration, we analyzed three agronomic traits from the actual spring wheat data set. Results illustrated that these data could be effectively analyzed using an extended additive-dominance model, which was more comparable to a conventional model. Actual data analysis revealed that all traits were significantly influenced by systematic field variation. Additive effects were significant for all traits and dominance effects were significant for plant height and time-to-flowering. Genetic effects were predicted and used to demonstrate that most spring wheat lines developed by the South Dakota State University breeding program exhibited good general combining ability effects for yield improvement. Thus, this study provides a general framework to appropriately analyze data in situations where field crop data are collected from non-replicated designs.

Last Modified: 12/19/2014
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