Amylose content and starch properties in emmer and durum wheat lines with different waxy proteins composition

Emmer wheat is a neglected crop that can be used in the breeding of modern durum wheat for quality. One important aspect of this quality is the starch composition, which is related to the waxy proteins. A collection of emmer wheat was analysed previously for waxy protein composition, and two new Wx-B1 alleles were found by sodium dodecyl sulfate-polyacrylamide gel electrophoresis and DNA sequencing analysis. It is necessary to analyse the effect of these alleles in starch properties and compare them to durum wheat ones.

In the current study, emmer lines carrying three different Wx-B1 alleles (Wx-B1b, -B1g, -B1c*), including one with the null allele (Wx-B1b), together with durum cultivars Langdon (Wx-B1a) and Mexicali (Wx-B1c'), were analysed for amylose content. Differences were detected between both species, and the line lacking Wx-B1 protein showed a remarkably low amylose content. In addition, data from blue value, swelling power and Rapid Visco Analyzer also suggested that there were differences in starch properties among the different Wx-B1 alleles.

The present study suggests that the amylose content in emmer (Wx-B1g) and durum (Wx-B1a) standard materials is not the same; therefore some starch properties are different between the two species. The variation found could be used to enlarge the gene pool of durum wheat and design new materials with desirable amylose content.