Document Type

Dissertation - Open Access

Award Date

1974

Degree Name

Doctor of Philosophy (PhD)

Department

Agronomy

First Advisor

Dale L. Reeves

Abstract

The objectives of this study were (a) to determine gene action, heritability and number of effective factors controlling protein content in oats, (b) to investigate the interrelationships of protein content with other agronomic characters, and (c) to evaluate the feasibility of utilizing A. sterilis germplasm in oat breeding projects. Four genetically distinct cultivars with protein content ranging from 15.7 to 26.6 percent were crossed in all possible combinations to make a complete set of diallel crosses. The data suggested additive gene action and partial dominance for protein content. Groat percentage and number of panicles showed overall partial dominance. Yield and days to heading indicated over-dominance, whereas height, plant weight and groat weight exhibited complete dominance. A. sterilis manifested dominance for early heading, low groat percentage and a large number of panicles. It exhibited recessiveness for yield, plant weight and groat weight. Narrow sense heritability for protein content varied from 41 to 83 percent while broad sense heritability ranged from 0 to 98 percent depending on genotype, environment and method used for computation. Genotype x environment interactions for protein content were significant. Frequency distribution for protein content in the F3 generation was reasonably symmetrical. Mean protein content was skewed toward the low protein content. F3 progeny from a cross involving two low protein parents had a lower average protein percentage than either parent. Some crosses had progeny with as high as 25 percent protein and yield above the mid-parent value were observed. Number of effective factors controlling protein content varied from 1 to 19, depending upon the method of determination and genetic diversity of the parents. Protein content exhibited negative correlations with yield, plant weight, height, number of spikelets, groat percentage, leaf length, leaf width and days to heading. A positive correlation of protein content was observed with awns, which is a A. sterilis characteristic. On the basis of standard partial regression coefficients, number of spikelets and yield were the most influential variables to predict protein content in the F1 and F3 generations, respectively. To predict yield, plant weight and number of spikelets were the best factors. There was a constancy of generation means for protein content in the F1, F2 and F3 generations. General combining ability, specific combining ability and reciprocal effects were significant in the F1 generation for protein content. Based upon this study, it can be concluded that the high protein content of A. sterilis can be combined with agronomic traits of A. sativa. This might be achieved by selecting from large populations of segregating material followed by backcrossing to A. sativa to recover better agronomic traits.

Library of Congress Subject Headings

Oats -- Breeding

Format

application/pdf

Publisher

South Dakota State University

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