Selection for low erucic acid and genetic mappingof loci affecting the accumulation of very long-chain fatty acids in meadowfoam seed storagelipids

摘要

Erucic acid (22:113) has been identified as an anti-nutritional compound in meadowfoam (Limnanthes alba) andother oilseeds in the Brassicales, a classification which has necessitated the development of low erucic acid cultivars forhuman consumption. The erucic acid concentrations of meadowfoam wild types (8%-24%) surpass industry standards forhuman consumption (≤3%). The goals of the present study were to develop low erucic acid lines and identify loci affectingthe accumulation of 22:1~(13)and other very long-chain fatty acids (VLCFAs) in meadowfoam seed storage lipids. LE76, alow erucic acid line, was developed by 3 cycles of selection in an ethyl methanesulfonate–treated wildtype population.LE76 produced 3% 22:1~(13), threefold less than the M_0 population. Wildtype x LE76F2populations produced continuous,approximately normal erucic and dienoic acid distributions. Loss-of-function mutations apparently did not segregate andindividuals with low 22:1~(13)concentrations (≤3%) were observed only inF2populations from hybrids withL. albasubsp.alba wild types. The meadowfoam genome was mapped and scanned for quantitative trait loci (QTL) affecting VLCFAprofiles in seed storage lipids by genotyping and phenotyping wildtype x low erucic acid F2 progeny. Composite intervalmapping identified 3 moderately large-effect erucic acid QTL. The low erucic acid parent transmitted favorable alleles for2 of 3 QTL, suggesting low erucic acid cultivars can be developed by combining favorable alleles transmitted by wildtypeand low erucic acid parents.