Inheritance of β‐Glucan Content of Oat Grain

Abstract

β‐Glucan in oat (Avena sativa L.) grain is primarily responsible for the beneficial effect of oat fiber on lowering blood serum cholesterol levels in humans. Plant breeding programs designed to genetically alter the β‐glucan contents of oat germplasm would benefit from information on the inheritance of this trait. Two experiments were conducted to study the inheritance of β‐glucan. Generation means analysis of five populations derived from biparental crosses between high and low β‐glucan lines and cultivars was used to determine the genetic effects controlling β‐glucan content in these populations. Parent‐offspring regression was performed by using β‐glucan data collected from individual plants of 166 oat lines and cultivars and their selfed offspring, allowing estimation of broad‐sense heritability for β‐glucan content in a diverse sample of oat germplasm. Additive gene effects were more important, and dominant gene effects were detected in only two of five biparental populations. No evidence of epistatic gene effects was found. Broad‐sense heritability was estimated as 0.55 on an individual plant basis. This estimate is based on the covariance of inbred parents and their selfed progeny, which involves twice the additive gene action of the reference noninbred population, as well as nonadditive genetic effects. Selection based on replicated progeny families would involve a higher heritability. A positive correlation between grain yield and β‐glucan was observed in the generation means analysis. These results suggest that plant breeders should be successful in altering β‐glucan in oat through direct selection for this genetically variable trait.