Biofortification of Pea and Lentil.

Field pea and lentil seeds, like those of other pulse crops, are rich in protein, slowly digestible carbohydrates, and fiber. To further enhance their nutritional value, research is in progress to increase the concentration and bioavailability of Fe, Zn, Se, carotenoids and folates. A 100 g dry weight serving of field pea or lentil supplied a substantial portion of the recommended daily allowance for adults of Fe, Zn, and Se. Association analysis in pea identified 9 single nucleotide polymorphisms (SNPs) associated with Fe concentration, and 2 SNPs associate with Zn concentration. Evaluation of bi-parental pea recombinant inbred line populations revealed QTLs associated with Fe, Zn, and Se concentration. A panel of 138 diverse cultivated lentil accessions phenotyped in four environments and genotyped using 1150 SNP markers exhibited a wide range of variation for seed Fe and Zn concentration, and marker-trait association analysis detected two SNPs tightly linked to seed Fe and one linked to seed Zn concentration. A number of putative candidate genes underlying detected loci encode Fe- and Zn-related functions. Selected pea RILs which segregated for Fe concentration showed positive correlation (r=0.38) between their Fe concentration and iron bioavailability. Field pea lines were identified with a 60% reduction in phytate-phosphorus concentration in seeds, while the inorganic (available) phosphorus concentration increased by a similar amount. A single recessive gene controls the low phytate trait and was mapped on pea chromosome 3. Phytate concentration was negatively correlated with iron bioavailability (r = −0.34 to -0.37) in pea lines segregating for phytate concentration. Dehulling lentil improved iron bioavailability, as did reducing the polyphenol concentration by introducing the zero tannin gene. Wild lentil species represent a potential resource for biofortification since 5 of 6 wild species are crossable with cultivated lentil and these accessions show diversity in Fe and Zn concentration. Total carotenoid concentration of 20 lentil cultivars ranged from 6-28 μg g^-1. Total carotenoid concentration of 12 pea cultivars ranged from 7-22 μg g^-1. Lutein was the most abundant carotenoid in lentil and pea seeds. Lutein concentration was positively correlated (r = 0.41) with iron bioavailability in a pea population. Low phytate-high carotenoid pea lines had up to 3-fold greater iron bioavailability than normal phytate checks. Total folate concentration of a small set of cultivars of chickpea was greater than that of lentil and common bean, while pea cultivars tested had substantially lower concentration. Current research is exploring more diverse germplasm for folate profile. This research shows potential positive associations between low phytate, high Fe, and high carotenoid concentration with improved iron bioavailability in pea and lentil seeds to improve Fe nutrition of foods.