Glucosinolates in the new oilseed crop meadowfoam: natural variation in Section Inflexae of Limnanthes, a new glucosinolate in L. floccosa, and QTL analysis in L. alba

Abstract

Meadowfoam, an oilseed crop grown in the Willamette Valley of Oregon, was developed from Limnanthes alba (Benth.), an herbaceous winter annual native to the west coast of North America. Meadowfoam oil is valued for unique properties attributed to the predominance of very long-chain fatty acids and desaturation at the Δ5 position. Seed meal remaining after commercial oil extraction contains intact glucosinolates and has potential pesticidal properties owing to isothiocyanate and nitrile glucosinolate derivatives. We identified and quantitated seed glucosinolates in four species of Section Inflexae of Limnanthes to assess variation for this trait in primary and secondary gene pools of cultivated meadowfoam. Glucosinolate content in seeds ranged from 30 to 204 μmol/g dry weight. Only glucolimnanthin (3-methoxybenzyl glucosinolate) was detected in L. alba, L. montana and L. gracilis, but L. floccosa contained glucolepigramin (3-hydroxybenzyl glucosinolate) as well as glucolimnanthin. Two QTL affecting seed glucosinolate content were identified in an inter-subspecific BC1 population derived from a cross between L. alba subsp. alba and L. alba subsp. versicolor.