Nondestructive assessment of sinapic acid esters in Brassica species: II. Evaluation of germplasm and identification of phenotypes with reduced levels

The seed of Brassica spp. contain high levels of sinapic acid esters (SAE). Because of their antiquality nature, the presence of SAE limits the use of Brassica meal as a source of high-quality protein. The objective of this s tudy was to search for material with reduced SAE content in Brassica spp. A collection of 1487 accessions of 21 species of Brassica and a set of 1361 samples of breeding material of rapeseed (B. napus L.) were analyzed for SA E content by using a previously calibrated near infrared reflectance spectr oscopy (NIRS) instrument. The accessions of the germplasm collection showed an average SAE content of 9.4 g kg(-1), ranging from 1.7 g kg(-1) in an en try of B. tournefortii Gouan to 15.5 g kg(-1) in an entry of B. carinata A. Braun. Low levels of SAE were found in B. barrelieri (L.) Janka, B. oxyrrh ina Coss., B. souliei (Batt.) Batt., and especially in B. tournefortii,,vit h an average SAE content of 4.1 g kg(-1) in 31 accessions. Breeding materia l of B. napus ranged from 5.0 to 17.7 g kg(-1). The samples with the lowest SAE content from both the germplasm collection (n = 112) and the breeding material (n = 75) were further analyzed by the laboratory reference method, with the low levels being confirmed. The SAE content was positively correl ated with oil content, and negatively correlated with protein and glucosino late contents. Because of the observed correlations, simultaneous selection for low SAE, low glucosinolate and high oil contents should be performed, The use of B. tournefortii germplasm having low SAE content in breeding pro grams can potentially reduce these compounds in cultivated Brassica oilseed s.