Genetic dissection of durum wheat milling and dough rheological properties.

Description of the Topic: Grain and semolina quality traits are essential selection criteria in durum wheat breeding. However, due to the high phenotypic costs and to the relatively high amount of seeds required for the analysis, only few advanced lines are typically completely characterized for their quality profile. For this reason, understanding the genetic basis of complex milling and rheological traits such as dough extensibility and how it relates to the different measurements of strength, could greatly help in the early selection of durum wheat lines with the desired quality characteristics. In addition, little is known about the genetic determinants of milling yield.

Several studies have investigated the genetic basis of wheat quality and different quantitative trait loci (QTL) and/or genes associated with specific quality traits have been identified. However, especially for durum wheat, most of the genetic studies have been limited to a relatively small number of analysis which in most of the cases were not explicative of the actual milling yield, dough rheological or end-use properties. For this reason, more studies exploring the genetic basis of semolina quality in durum wheat are needed.

Hence, the objectives of this study are to: 1) Characterize a panel of modern lines representative of the diversity of the CIMMYT durum wheat breeding program and suitable for genome-wide association study (GWAS) for their milling quality, dough rheological properties and protein quality; 2) Understand the effect of the genotype (G), environment (E) and of the G x E interaction on the variation of the analyzed traits; 3) Perform a GWAS analysis to detect genomic regions significantly associated with the measured traits and 4) Test already available molecular markers associated with the traits of interest and develop new ones. 

Work expectations: The candidate will be in charge of: 1) Determining milling yield and analyzing the dough rheological quality of the panel grown in 2 different environments for two years using equipment such as mixograph, alveograph and Texture Analyzer; 2) Using statistical analysis to understand the heritability of the different traits; 3) Characterizing the protein profile of the selected wheat lines through methods such as SDS-PAGE; 4) Performing a GWAS analysis and 5) Testing and developing different molecular markers associated with durum wheat quality. All the results obtained from this study are expected to be clearly organized and compiled in the form of at least a scientific paper.

Required skills: Good knowledge of plant genetics and ability to work with chemical/biochemical methodologies in the laboratory are required. The candidate will work collaboratively with colleagues and provide necessary assistance when requested.