Degree

Doctor of Philosophy (PhD)

Department

School of Plant, Environmental and Soil Sciences

Document Type

Dissertation

Abstract

The LSU AgCenter Hybrid Rice Breeding Program is developing two-line hybrids with high yields and resistance to the herbicide Quizalofop-P-Ethyl (QPE) to control weedy red rice and prolong Clearfield® and Provisia® weed control technologies. The first objective of this research was to develop and characterize QPE-resistant, environment-sensitive genic male sterility (EGMS) lines adapted to Louisiana field conditions. Five promising EGMS lines with desired agronomic traits were selected and evaluated from 2017-2020 that will lay the foundation for development of new QPE-resistant hybrids for the Louisiana rice industry. The second objective was to evaluate field performance of QPE-resistant experimental hybrids derived from crosses of the selected EGMS lines. Three QPE-resistant hybrids with high yields comparable to commercial hybrids were identified in 2019 and 2020 trials that will be further evaluated in the 2021 breeding pipeline. Efficient production of parental and hybrid seed is a crucial component of hybrid breeding that requires unique methods and approaches compared to inbred breeding schemes. The third objective of this research was to develop and optimize seed production methods for parental lines and hybrids under Louisiana field conditions. Crossing blocks with three rows of female and male plants planted at the same time allowed sufficient seed production for small-plot yield trials. Results from this research show that optimization in plot layout, planting date, seeding rate, and timing of GA3 plant growth regulator are key to maximizing parental and hybrid seed production for two-line hybrid breeding in Louisiana.

Date

3-27-2021

Committee Chair

Oard, James H.

Available for download on Monday, March 13, 2028

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