Genotype × Environment Interactions, Heritability, and Trait Correlations of Sinapate Ester Content in Winter Rapeseed (Brassica napus L.)

Improving the meal and protein quality for feed and food purposes is of increasing importance in canola (Brassica napus L.). The phenolic acid ester content contributes to the bitter taste, astringency, and dark color of rapeseed meal products. The predominant phenolic acid esters are sinapate esters (SE), which make up 1 to 2% of the seed dry matter. The objective of the present study was to analyze the genetic variation and the genotype × environment interactions for SE content and composition in three populations of doubled haploid lines. The populations were grown in three to four environments in Germany. The following SE were analyzed by HPLC: sinapoylcholine (sinapine), sinapoylglucose, and a minor group of other SE which includes sinapate. The three populations showed a highly significant variation for the total SE content, and sinapine was the predominant sinapate ester compound. The analysis of variance showed highly significant effects for the genotype (G), the environment (E) and the G × E interactions for all three populations. In two of the populations the G × E interaction variance components were less than half of the genetic variance, in one population it was slightly higher. The estimates for heritability of the individual and total SE were generally high and ranged from 0.57 to 0.93. A reduction of sinapate ester content was not associated with a change in oil, protein, and glucosinolate content.