and forms hydroperoxides. These products are thought to be involved in plant defense, wound response, senes-Lipoxygenases constitute a family of enzymes that catalyze the cence, and development (Hildebrand, 1989). Under cerbreakdown of lipids, resulting in products that may have undesirable effects. These enzymes can affect pasta color and cause off-flavors. The tain processing conditions, high levels of lipoxygenase purpose of this study was to map the loci associated with lipoxygenase activity destroy the yellow color in pasta by oxidation activity in seeds of a durum wheat (Triticum turgidum ssp. durum ) (Joppa and Williams, 1988). Some plant lipoxygenase population to determine if lipoxygenase activity is associated with reaction products also are implicated in the production flour color. Seed of the parents, Jennah Khetifa and Cham 1, and the of aroma or undesirable flavors and odors. In barley recombinant inbred population consisting of 113 progeny lines were (Hordeum vulgare L.), this enzyme is thought to be used to assay lipoxygenase activity and flour color. A saturated molecresponsible for staling in beer (Drost et al., 1990; Wu ular-marker linkage map for this population was previously conet al., 1997). Lipoxygenase activity is directly affected structed. Allele specific primers targeting the wheat homolog to barley by storage conditions. Kaukovirta et al. (1998) measured LoxA were designed, and a fragment length polymorphism resulting from a miniature inverted-repeat transposable element (MITE) inser-oxidation of linoleic acid in flour suspensions of barley tion in an intron of the durum wheat LoxA homolog allowed mapping and malt samples. Results showed that there was great of the locus to chromosome 4BS. To measure lipoxygenase activity, variability of lipoxygenase activity profiles from a single spectrophotometric changes were recorded. Cham 1 had a change in malting, depending on the duration of storage before absorbance of 0.284 units of absorbance over 1 min compared with the assays. They concluded that the rate of lipoxygenase 0.752 units for Jennah Khetifa. Quantitative trait locus analysis of reaction should be considered as a quality factor of malt these data indicated that most of the lipoxygenase activity was associbecause of its effect on malting. In soybean [Glycine ated with the wheat lipoxygenase gene (Lpx ) on chromosome 4BS. max (L.) Merr.] seeds, lipoxygenases are responsible for A quantitative trait locus for vitreous appearance of seeds also was production of the unpleasant beany flavors that have associated with this locus. Flour color was not correlated with lipoxygenase activity in this population. With this knowledge, marker-as-Abbreviations: MITE, miniature inverted-repeat transposable element.