The Genetic Control of Stem Mechanical Properties in Oilseed Rape

Oilseed rape (Canola) is a crop type of Brassica napus.Studies on the mechanical properties of the stems of B. napus accessions provide insights into the susceptibility of plants to lodging, and are part of the suite of research activities necessary for the optimisation of rapeseed straw as a feedsock for lignocellulosic ethanol production. In this study, we explored the mechanical properties of a diverse panel of B.napus accessions and identified important variation in both material strength and structural strength. Furthermore, the chemical composition of all material tested was determined through Fourier transform infrared spectroscopy, allowing the identification of correlations between the stem chemistry and mechanical properties. In order to uncover the genetic control of these important traits, we conducted an Associative Transcriptomics approach using Illumina transcriptome sequencing, which enabled the identification of 101,644 B.napus SNPs through the alignment of sequence data corresponding to 94,558 unigenes. This powerful approach allows the detection of both SNP marker and gene expression marker associations. With trait data available across multiple years and locations, this Associative Transcriptomics approach enabled the identification of a number of very promising associations for both structural and material strength traits. Using comparative genomics, we identified a number of candidate genes, for which Arabidopsis thalianahomologues have been described. The ultimate aim of this study is to provide markers for these mechanical traits, allowing breeders to take a marker assisted selection approach to crop improvement.