David Karki

Document Type

Thesis - University Access Only

Award Date

2007

Degree Name

Master of Science (MS)

Department / School

Agronomy

Abstract

Breeding to improve soybean oil quality has intensified over the past decade. Stability of performance across environments is essential for consistent production of modified fatty acid levels. This study was conducted in 2004 and 2005 growing seasons to determine fluctuations of modified fatty acid profiles across diverse northern environments, with the main focus on linolenic acid. We studied the fatty acids most likely to fluctuate (palmitic, stearic, oleic and linoleic) with fluctuations in linolenic acid concentrations. The experiment contained 38 lines (maturity groups 0, I & II), derived from two crosses of SD high protein lines with two low linolenic parents. The study included three high yield checks, the two low linolenic parents and the two high protein parents. All 45 lines were tested in seven eastern SD locations in two years. In the combined analysis, location and year effects were not significant. None of the individual fatty acids showed significant entry x location effects. For stearic and oleic acids, Year x location effects were significant. Maturity group effects were significant for some fatty acids including linolenic acid. Means of palmitic, oleic and linolenic acids showed significant differences among maturity groups. There were significant differences among the lines for oleic and linolenic acid at all locations. Significant positive relationships were found between linolenic and palmitic acid. Relationships of linolenic acid with oleic and linoleic acids were found significantly negative. Regression coefficients (bi) of lines which had less than 4% linolenic acid ranged from -0.85 to 0.78 and mean deviation from regression (S2 d) ranged from -0.39 to -0.07. These data indicated that low linolenic acid was very stable across environments and can be maintained in northern environments without negative effects on other important traits.

Library of Congress Subject Headings

Linolenic acids

Fatty acids

Soy oil

Soybean -- Breeding -- South Dakota

Format

application/pdf

Number of Pages

43

Publisher

South Dakota State University

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