|Holland, Jim - Jim|
Submitted to: Crop Science
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: 12/4/2000
Publication Date: N/A
Interpretive Summary: The "active ingredient" in oatmeal that lowers cholesterol in humans is b-glucan. Therefore, development of oat varieties with higher levels of b-glucan in the grain would improve the nutritional value of the crop and may enhance the economic value of the grain for U.S. oat growers. We evaluated individual plants from two large oat populations for their b-glucan content, and selected the plants with highest b-glucan content from each population. Lines from the selected plants were crossed to make two new selected populations. Lines from both original and selected populations were evaluated in the field to determine if selection resulted in higher levels of b-glucan content. Our results show that the selections were effective, and we increased the mean b-glucan of the two populations by 11% in one population and by 4% in the other. Some of the best lines from these populations had b-glucan contents greater than any commercial cultivar tested. These lines will be useful to oat breeders to develop cultivars with higher b-glucan contents.
Technical Abstract: Oat (A. sativa L.) b-glucan lowers serum cholesterol in humans. Development of oat cultivars with greater groat b-glucan content would increase the nutritional and economic value of the crop. The response to phenotypic selection among individual S0 plants for greater b-glucan content in two genetically broad-based populations was determined by evaluating random S0:1 lines from initial and selected generations of each population in a field experiment in 1996 and 1997 at two Iowa locations. The mean b-glucan content increased from 54.0 g kg-1 to 59.8 g kg-1 in one population, and from 63.5 g kg-1 to 66.1 g kg-1 in the other. Genetic variance b-glucan content decreased 9% and 22% in the two populations, respectively. Heritability estimates ranged from 0.49 to 0.65 on a sample-basis and from 0.80 to 0.88 on a line mean-basis. Additive variance was the only substantial component of genetic variance. Ranking of S0:1 lines for b-glucan content across environments was generally consistent, with correlations of genotypic b-glucan contents between pairs of environments ranging from 0.63 to 0.82. Some experimental lines had significantly greater b-glucan content than the best check cultivars and lines. Phenotypic selection for greater groat b-glucan content will be effective for developing cultivars with elevated b-glucan contents.