Breeding to increase the concentration of 2-phenylethyl glucosinolate in the roots of Brassica napus

Root concentrations of 2-phenylethyl glucosinolate in canola, Brassica napu s, influence the susceptibility of the crop to the root lesion nematode (Pr atylenchus neglectus), as well as the nematicidal effect of root tissues as they degrade in the soil. Plants containing high 2-phenylethyl glucosinola te should therefore reduce soil populations of P. neglectus. A selection pr ogram was developed to increase the proportion of total glucosinolates cont ributed by 2-phenylethyl glucosinolate in the roots of B. napus cv. Dunkeld . Variation within this accession was observed to be stable across the S-1 and S-2 generations. The segregation observed for 2-phenylethyl glucosinola te percentage suggested that the trait was encoded at a single locus, with the "high" phenotype being dominant. Plants with the high 2-phenylethyl glu cosinolate phenotype (>45% of total glucosinolates) were shown to he signif icantly more resistant to P. neglectus than otherwise identical "low" pheno types (<45% of total).