Molecular characterization of waxy alleles in three subspecies of hexaploid wheat and identification of two novel Wx-B1 alleles.

Two novel Wx - B1 null alleles that enlarge the genetic variability for this wheat gene were characterized, whose effects on wheat quality could be different to those of the Wx - B1b allele. The starch composition of wheat grain has a primary influence on flour quality. Wheat starch consists of two types of glucose polymers: amylose (22-35% of the total) and amylopectin (68-75% of the total).

Molecular characterization of a new waxy allele with partial expression in spelt wheat.

Starch composition which is dependent on the waxy protein, the enzyme responsible for amylose synthesis in the grain, is an important aspect of the wheat quality. In this report, we describe the characterization of a novel Wx-A1 allele (Wx-A1g formerly known as -Wx-A1a) in Spanish spelt wheat lines which is responsible for a remarkable decline in the concentration of Wx-A1 protein found in the endosperm. Comparison of the DNA sequences in the Wx-A1a and Wx-A1g alleles showed the presence of a 160-bp insertion within the fourth intron in the latter.

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

Background: 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.

Multiple effects of the starch synthase II mutation in developing wheat endosperm.

A line of wheat (Triticum aestivum L.), sgp-1, that does not express starch synthase II (SSII, also known as SGP-1) has previously been reported. In this study, F1 derived doubled haploid lines with homozygous wild type or mutant alleles for SGP-1 genes were identified from a cross between the original mutant and a wild type Australian cultivar.